1. family and parenting
2. children

Evaluation of Tuberculosis Score Charts against Bacteriologically Confirmed
Pulmonary Tuberculosis by Induced Sputum among Children at Bugando Medical
Centre
Issa Sabi, MD
A dissertation submitted in partial fulfillment of the requirements
for the Degree of Master of Medicine (Paediatrics and Child Health) of the Catholic
University of Health and Allied Sciences
2014
1
DECLARATION AND COPYRIGHT
I Issa Sabi hereby declare that the work presented in this dissertation has not been
presented and will not be presented to any other university for similar or any other
degree award.
Signature: …………………………………DATE: ………………………………….
This dissertation is a copyright material protected under the Berne Convention, the
Copyright Act 1999 and international and national enactment, in that behalf on
intellectual property. It may not be reproduced by any means, in full or in part, except
for short extracts in fair dealing, for research or private study, critical scholarly review
or discourse with an acknowledgement, without written permission of the directorate
of postgraduate studies, on behalf of both the author and the CUHAS- Bugando.
i
CERTIFICATION
The undersigned certify that they have read and hereby recommend acceptance for
examination by the Catholic University of Health and Allied Sciences-Bugando, a
dissertation
titled:
Evaluation
of
Tuberculosis
Score
Charts
Against
Bacteriologically Confirmed Pulmonary Tuberculosis by Induced Sputum
among Children at Bugando Medical Centre” in partial fulfilment for the
requirement of the award of degree of Masters Medicine (Paediatrics and Child
Health).
Signature ……………………………… Date …………………………..
Dr. Rogatus Kabyemera, MD, M.MED
Peaditrician, Department of Peadiatrics
Bugando Medical Centre
Signature ……………………………… Date …………………………..
Prof. Stephen .E. Mshana, MD, M.Med, PhD
Associate Professor of Microbiology and Immunology
Catholic University of Health and Allied Sciences - Bugando
Signature ……………………………… Date …………………………..
Dr. Robert N. Peck, MD
Assistant Professor of Medicine and Pediatrics, Weill Cornell Medical College
Consultant physian, Department of Internal Medicine,
Catholic University of Health and Allied Sciences - Bugando
ii
DEDICATION
This work is dedicated to my lovely wife Hadija
iii
ACKNOWLEDGEMENT
This work is the result of the contributions of many people. I would like to express
my sincere gratitude to:
My supervisors Dr. Rogatus Kabyemera, Prof. Stephen E. Mashana and Dr. Robert
Peck, for their continuous support and valuable inputs to this work.
The Department of Peadiatrics and Child Health, BMC for their valuable
contributions and continuous support towards this study.
Mrs Lisa E. Gerwing-Adima, TB laboratory of BMC for her valuable advice and
continuous support in all laboratory related matters.
Dr Kassanga, department of radiology of BMC, despite his busy schedule he was able
to interpret chest X-rays of all patients enrolled in the study.
Dr. Benson Kidenya, Department of Biochemistry of Catholic university of health and
allied sciences, for statistical analysis.
Dr Andrea Rachow, Department of Infectious Diseases & Tropical Medicine,
Klinikum der Universitaet Muenchen and Dr. Petra Clowes, NIMR-Mbeya Medical
Research Centre (NIMR-MMRC) for their great support and facilitating the
availability of LJ culture slants and related consumables and for facilitating the
training and providing some of the equipments for sputum induction.
The office of the Regional TB and Leprosy Coordinator in Mwanza, for realizing the
importance of this study and provide the support for Xpert MTB/RIF assay and its
related consumables.
iv
The parents and care takers of the all the children who were enrolled in the study for
their consent to participate in this study. Without their consent this study would not
have been done.
My fellow residents, for their continuous support and inputs in this study.
Lastly but not least my family for bearing with me during the time of this study. I
spent very little time with them for the entire period of the study.
v
Table of Content
DECLARATION AND COPYRIGHT........................................................................... i CERTIFICATION .........................................................................................................ii DEDICATION ............................................................................................................. iii ACKNOWLEDGEMENT ............................................................................................ iv LIST OF TABLES ........................................................................................................ xi LIST OF FIGURES .....................................................................................................xii OPERATIONAL DEFINITION ................................................................................ xiii ABBREVIATIONS ..................................................................................................... xv ABSTRACT...............................................................................................................xvii 1.0 INTRODUCTION .............................................................................................. 1 1.1 Background ..................................................................................................... 1 1.2 Problem Statement .......................................................................................... 3 1.3 Rationale of the Study ..................................................................................... 3 1.4 Research Questions ......................................................................................... 4 1.5 Objectives ........................................................................................................ 4 1.5.1 Broad Objective ....................................................................................... 4 vi
1.5.2 2.0 Specific Objectives .................................................................................. 4 LITERATURE REVIEW ................................................................................... 6 2.1 Difficulties in Diagnosing Pulmonary TB in children .................................... 6 2.2 Pediatric TB Score chart ................................................................................. 6 2.3 Specimen Recovery Methods .......................................................................... 8 2.4 Confirmation of Pulmonary TB in children ....................................................... 10 3.0 MATERIALS AND METHODS...................................................................... 12 3.1 Site Description ............................................................................................. 12 3.2 Study design .................................................................................................. 12 3.3 Sample size .................................................................................................... 12 3.4 Study Population ........................................................................................... 13 3.5 Data collection............................................................................................... 14 3.5.1 Standard diagnostic procedures ............................................................. 14 3.5.2 Laboratory procedures ........................................................................... 16 3.5.3 Study duration and management of study subjects ................................ 17 3.6 Outcome of the study .................................................................................... 18 3.7 Study Variables ............................................................................................. 18 vii
3.8 Statistical analysis ......................................................................................... 18 3.9 Data quality and assurance ........................................................................... 19 3.10 Ethical consideration ..................................................................................... 19 4.0 RESULTS ......................................................................................................... 21 4.1 Baseline Characteristics ................................................................................ 21 4.2 Specimen recovery ........................................................................................ 23 4.2 Specimen recovery ........................................................................................ 24 4.3 Common presenting symptoms ..................................................................... 24 4.4 Radiological Characteristics .......................................................................... 25 4.5 Patients Follow-up.............................................................................................. 26 4.6 Yield for Mycobaterium tuberculosis from one induced sputum ................. 27 4.7 The proportion of PTB cases ......................................................................... 27 4.8 Sensitivity, Specificity, & Positive/Negative predictive values .................... 28 4.9 Factors associated with microbiologically confirmed PTB ............................... 29 5.0 DISCUSSION ................................................................................................... 32 5.1 Sputum Induction as a method of specimen recovery method...................... 32 5.2 Proportion of patients who had pulmonary tuberculosis ............................... 33 viii
5.3 Sensitivity and specificity of the TSCs ......................................................... 34 5.4 Factors associated with confirmed TB .......................................................... 35 6.0 CONCLUSIONS............................................................................................... 37 7.0 RECOMMENDATIONS .................................................................................. 38 8.0 LIMITATIONS OF THE STUDY.................................................................... 39 9.0 REFERENCES ................................................................................................. 40 10.0 APPENDICES............................................................................................... 44 10.1 Data Collection Form ................................................................................ 45 10.2 Standardized Chest X-ray Review Tool .................................................... 50 10.3 Information Sheet and Informed Consent Form ........................................... 52 10.3.1 Information Sheet and Informed Consent Form .................................... 52 10.3.2 Karatari ya maelezo na form ya ridhaa .................................................. 55 10.4 Sputum induction .......................................................................................... 58 10.5 Diagnostic Scoring Systems .......................................................................... 63 10.5.1 Keith Edward Score Chart ..................................................................... 63 10.5.2 MASA System ....................................................................................... 64 10.5.3 Fourie Scoring System ........................................................................... 64 ix
10.5.4 Brazilian MoH Scoring System ............................................................. 65 10.6 Tuberculin Skin Testing ................................................................................ 66 10.7 Study Budget ............................................................................................. 71 10.8 Test for HIV Diagnosis ................................................................................. 72 10.9 Research Clearance Certificate.................................................................. 74 x
LIST OF TABLES
Table 1: Baseline characteristics of study participants ................................................ 22 Table 2: Follow up among patients enrolled in the study ............................................ 26 Table 3: Yield for MTB from one induced sputum among patients enrolled in the
study ............................................................................................................................. 27 Table 4: TB cases based by Peadiatrics TB score charts and Diagnostic classification
among patients enrolled in the study ........................................................................... 28 Table 5: Sensitivity, specificity, PPV and NPV of TSCs against microbiologically
confirmed pulmonary TB............................................................................................. 29 Table 6: Baseline characteristics associated with confirmed TB among patients
enrolled in the study ..................................................................................................... 30 Table 7: Radiological features associated with confirmed Pulmonary TB among
patients enrolled in the study ....................................................................................... 31 xi
LIST OF FIGURES
Figure 1: Study flow diagram ...................................................................................... 23 Figure 2: Common presenting symptoms among patients enrolled in the study ......... 25 xii
OPERATIONAL DEFINITION
Children were categorized by using classification group on the basis of different
clinical, radiological, and microbiological information as shown below:
Pulmonary TB:
A child with pulmonary TB symptoms who had M. tuberculosis
confirmed in sputum by culture or Xpert MTB/RIF assay, or a
child without M. tuberculosis confirmation but had clinical and
radiologic features that prompted empirical treatment for
pulmonary TB.
Pulmonary TB case was further categorized as shown below based on diagnostic
classification as previously proposed by Graham et al (1). In addition to that
classification Xpert MTR/RIF assay was also a confirmatory test for pulmonary
tuberculosis in this study.
Confirmed
tuberculosis:
Patients were classified as ‘‘confirmed TB’’ when they
presented with:
1. At least 1 of the signs and symptoms suggestive of
tuberculosis
and
2. Microbiological confirmation is obtained by culture,
Xpert MTB/RIF assay
Probable tuberculosis:
Patients were classified as ‘‘probable tuberculosis’’ cases
when they presented with:
1. At least 1 of the signs and symptoms suggestive of
tuberculosis
and
2. Chest radiography is consistent with intrathoracic
disease due to Mycobacterium tuberculosis
and
3. There is at least 1 of the following:
(a) A positive clinical response to anti-tuberculosis
treatment
(b) Documented exposure to M. tuberculosis
(c) Immunological evidence of M. tuberculosis
xiii
infection
Possible tuberculosis:
Patients were classified as ‘‘possible tuberculosis’’ when
they presented with at least 1 of the signs and symptoms
suggestive of tuberculosis
and either
(1) One of the following:
(a) A positive clinical response to anti-tuberculosis
treatment
(b) Documented exposure to M. tuberculosis
(c) Immunological evidence of M. tuberculosis
infection
or
(2) Chest radiography is consistent with intrathoracic
tuberculosis disease
NB: if at least 1 of (1) and (2) are both present, then
this case should be classified as ‘‘probable
tuberculosis.’’
PTB unlikely:
Symptomatic but not fitting the above definitions and no
alternative diagnosis established
Not PTB tuberculosis:
Established alternative diagnosis or no clinical
deterioration on follow-up in the absence of tuberculosis
therapy
xiv
ABBREVIATIONS
AFB
Acid Fast Bacilli
BAL
Bronchoalveolar Lavage
BMC
Bugando Medical Centre
CUHAS
Catholic University of Health and Allied Sciences
CXR
Chest X-ray
GL
Gastric Lavage
HIV
Human Immunodeficiency Virus
IUATLD
International Union Against Tuberculosis and Lung Disease
LIP
Lymphocytic Interstitial Pneumonia
LJ
Löwenstein - Jensen
MASA
Medical Association of South Africa
MoHSW
Ministry of Health and Social Welfare
MTB
Mycobacterium Tuberculosis
NPA
Nasopharyngeal Aspiration
NTLP
National Tuberculosis and Leprosy Control Programme
PCP
Pneumocystis jerovecii pneumonia
PPTB
Paediatric Pulmonary Tuberculosis
PTB
Pulmonary Tuberculosis
RIF
Rifampicin
xv
TB
Tuberculosis
TSC
Tuberculosis Score Chart
TST
Tuberculin Skin Test
WHO
World Health Organization
xvi
ABSTRACT
Background: Bacteriological confirmation of childhood TB continues to be difficult
due to the unavailability of diagnostic facilities, difficulties in obtaining samples, and
poor performance of smear microscopy. As a result various peadiatric TB scoring
tools were invented in order to help in clinical diagnosis. Therefore this study was
done to evaluate various peadiatric tuberculosis score charts for the diagnosis of
pulmonary TB against bacteriologically confirmed pulmonary TB in the paediatric
department of Bugando Medical Centre (BMC).
Material and Methods: A cross sectional study was conducted from October 2013 to
April 2014 among children suspected to have pulmonary TB at BMC. All children
were assessed for TB by using pediatric tuberculosis score charts (Keith Edward,
MASA, Fourie and Brazil MOH). Sputum induction was attempted in all patients to
obtain sputum which was examined by fluorescent acid fast smear, LJ culture and
Xpert MTB/RIF assay. Sensitivity, specificity, positive predictive values and negative
predictive value of the score charts against pulmonary TB cases were determined.
Results: A total of 192 patients were enrolled in the study over a period of 5 months.
Males formed 53.7% of all the participants. Median (IQR) age was 1.9 (1.2 – 4.4)
years. Sputum specimen was obtained in 187 (97.4%) patients; sputum induction was
successfully performed in 183 (95.8%) patients. Forty (20.8%) patients were
diagnosed with pulmonary TB; among them 10 (5.2%) had confirmed pulmonary TB.
Generally, the sensitivity of pediatric TB score charts was poor for diagnosing
pulmonary TB (10% - 50%). No baseline characteristics had significant association
with confirmed pulmonary TB. Airspace opacification and cavities on chest X-ray had
strong association with confirmed PTB with p-values of <0.01 and 0.01 respectively.
Conclusion: Sensitivity and specificity to detect pulmonary TB with peadiatric TB
score charts evaluated in this study were very low. Induced sputum is possible in our
setting therefore bacteriological confirmation of pulmonary TB should be attempted
in every child suspected to have TB. CXR components should be incorporated in all
TB
scores
to
increase
xvii
the
sensitivity.
1.0
INTRODUCTION
1.1
Background
Tuberculosis (TB) is still a major public health problem and associated with high
morbidity and mortality; globally about nine million new cases and two million deaths
occur annually. It is estimated that about one-third of the world population has been
infected by the mycobacterium that causes TB. Childhood TB contributes a
significant proportion of the global TB burden. Of the estimated 9 million new TB
cases that occur annually about one million cases (11%) occur in children less than 15
years of age. About 75% of the reported TB cases in children occur in 22 high TB
burden countries (2,3).
According to the Global TB report of 2011, Tanzania ranks at number 20 among 22
high TB burden counties.
Data from the National TB and Leprosy Programme
(NTLP) from 2004 to 2011 show that childhood TB contributes about 10% to all
notified cases in Tanzania. In 2010 alone, there were 5,216 TB case notifications in
children less than 15 years of age, which accounted for 8.7% of the total new case
notifications. However, data from studies done in Kilimanjaro and Mwanza regions
suggest that the contribution of childhood TB in Tanzania might be even higher than
the estimated worldwide average (4,5).
The magnitude of TB disease among children in Tanzania is difficult to ascertain due
to challenges in diagnosing and reporting. In a retrospective review of the TB registry
at Bugando Medical Centre (BMC) a total number of 1,023 TB patients were treated
from January to December 2012 including 79 children of less than 15 years of age
who contributed about 7% of the reported TB cases. There were no confirmed TB
1
cases; therefore all children were treated based on either Keith Edward score chart or
X-ray findings.
In most resource-constraint settings, the diagnosis of pulmonary TB (PTB) in children
is usually based on history of TB contacts, positive Tuberculin Skin Test (TST) and
radiological findings suggestive of TB. However, in developing countries the
diagnosis of PTB is usually difficult because the contact history is often not clear, the
tuberculin test is often false positive due to routine BCG immunization, and because
of difficulties in interpreting chest radiographs especially in HIV-coinfected patients
where HIV-related pulmonary disease such as lymphocytic interstitial pneumonitis
(LIP). But also common viral and bacterial infections of the lung may present with
similar symptoms and radiological patterns.
Confirmation of tuberculosis by culture, which is considered the gold standard for
confirmed TB diagnosis, is important where, for example, there is difficulty in clinical
diagnosis, the contact history is not known or drug sensitivity is required. Sputum
induction is the preferred method for collecting sputum in children because children
do not have enough strength to expectorate. Several studies have shown that induced
sputum has a higher diagnostic yield than expectorated sputum in children and is
comparable to or better than gastric lavage specimens (6–10). Sputum induction has
been shown to be a safe and effective procedure even in children as young as 1 month
of age (8,11).
Currently in Tanzania, it is recommended that sputum induction is performed at
district, regional and zonal referral hospitals, where appropriate equipments and
personnel are available (Tanzania National Guideline for Management of TB in
2
Children, 2012). Despite of availability of experts at BMC, sputum induction to
obtain sputum sample is so far not performed on children suspected to have TB.
1.2
Problem Statement
Accurate and consistent diagnosis is critical for the effective management of children
with TB, for measuring the precise burden of childhood TB, the TB-related morbidity
and mortality, and to establish drug susceptibility patterns. In our setting, despite of
the availability of facilities and expertise bacteriological confirmation of childhood
TB continues to be difficult due to the difficulty in obtaining samples in children,
poor performance of smear microscopy, long turnaround time for culture results and
the perception that microbiologic yield is low. Currently, several studies have
confirmed that microbiologic confirmation is feasible and useful to exclude drug
resistant TB (6).
Clinical scoring systems such as the Keith Edward Scoring Chart (12) have
commonly been used as a diagnostic tool to diagnose TB in children. However those
systems are poorly validated, may not be generalizable to different settings, and are
not adapted for use in HIV-infected children (6,13).
1.3
Rationale of the Study
This study evaluated the Keith Edwards, MASA, Fourie and Brazilian MoH
diagnostic score charts against culture for the diagnosis of peadiatric PTB. While in
other setting, various clinical scores have been shown to have low sensitivity and low
specificity especially when applied in HIV-endemic areas (14,15), these scoring
systems are are still being used in our setting for want of a better alternative.
3
Sputum induction is not routinely done at BMC and many hospitals in Tanzania.
Therefore, this study also investigated the feasibility of sputum induction as a method
for sample collection, in order to improve the diagnosis of peadiatric PTB in our
setting.
This study was also aiming to provide baseline data from our local setting that would
be helpful to plan future studies of childhood TB. Prior studies of pediatric TB at
Bugando have not included confirmation of PTB with culture and microscopy, so the
true incidence of TB among pediatric inpatients at BMC is not yet known.
1.4
Research Questions
What is the sensitivity and specificity of pediatric tuberculosis score charts compared
to microbiologically confirmed pulmonary TB case?
1.5
Objectives
1.5.1 Broad Objective
To evaluate paediatric tuberculosis score charts in the diagnosis of pulmonary TB
against culture or Xpert MTB/RIF assay performed on induced sputa from children
suspected to have TB in the pediatric departments of BMC.
1.5.2 Specific Objectives
1. To determine the proportion of patients diagnosed with pulmonary
tuberculosis among children suspected to have pulmonary TB in the peadiatric
department of BMC.
4
2. To determine the sensitivity and specificity of pediatric TB score charts
against microbiologically confirmed pulmonary TB cases among children
suspected to have TB in the peadiatric department of BMC.
3. To determine the baseline characteristics which are associated with
bacteriologically confirmed pulmonary TB among children suspected to have
PTB in the peadiatric department of BMC.
4. To assess the utility of sputum induction performed among children suspected
to have pulmonary TB in the Peadiatric department of BMC.
5
2.0
LITERATURE REVIEW
2.1
Difficulties in Diagnosing Pulmonary TB in children
The difficulties in diagnosing peadiatric pulmonary TB (PPTB) have been known for
decades. The main contributing factors for diagnostic difficulties are the nonspecificity of signs and symptoms, pauci bacillary nature of PPTB, problem with
specimen recovery methods and limitations of the diagnostic test itself (7).
Symptoms of TB in children are often non-specific, and a significant proportion of
paediatric patients may be asymptomatic during the initial stages of the disease.
Among those who are symptomatic the symptoms may include cough, fever, weight
loss, night sweats, and wheezing. Several studies have been done to attempt to
determine signs and symptoms that can be used for PPTB diagnosis but results
showed poor sensitivity and specificity because the symptoms of PPTB can be similar
to symptoms of other diseases such as pneumonia, asthma and congenital pulmonary
diseases (7,16).
2.2
Pediatric TB Score chart
The clinical presentation of pulmonary tuberculosis is often non-specific and there is
increased variability in the interpretation of radiological findings. These variabilies
become even more evident in the presence of HIV co-infections when other
opportunistic infections present with overlapping clinical and radiological findings
(6,14,15).
To improve the diagnostic accuracy several pediatric Tuberculosis Score Charts
(TSC) have been designed for resource limited countries to facilitate the diagnosis of
6
TB in children. TSC are mainly checking the combinations of clinical and
radiological evidence of disease in the presence of a positive history of TB contact or
a positive TST result.
Several studies have described the performance of those
scoring system (6,7,12–15,17,18); however those systems are poorly validated and
cannot be generalized in different epidemiological settings and have not been adapted
for use in HIV endemic areas (6,13).
The Keith Edwards score chart has been recommended by the Tanzania NTLP for the
diagnosis of TB in children (Tanzania National Guideline for Management of TB in
Children, 2012) and is commonly used at BMC (BMC treatment guidelines). This
score was developed in Papua New Guinea (PNG) and is based almost entirely on
clinical findings; microbiological tests and radiology results are not included in the
main score, as it is argued that these investigations are not widely available. This
score was designed for the diagnosis of both pulmonary and extra pulmonary TB. The
original study proposes a score >7 being suggestive of TB based on clinical
experience, but this is not validated (12). Studies that have been done to evaluate the
performance of Keith Edwards score chart have shown good sensitivity and
specificity if applied to children not infected with HIV (17,18); however, in HIV
endemic areas it has been shown to have very low specificity (14,19).
The Fourie score was designed in 1993 when the International Union Against
Tuberculosis and Lung Disease (IUATLD) appointed a task group to develop a
scoring system which will show more acceptable sensitivity, specificity, and positive
predictive values. The initial assessment of the Fourie score showed a sensitivity and
specificity of 41% and 44%, respectively, for young children (0–4 years) compared to
older children (5 – 14 years) with sensitivity and specificity of 62% and 50%
7
respectively (20). They therefore proposed the score to be applied as screening tool to
select individuals with a high probability of tuberculosis for further examination at a
referral centre.
The Brazilian MOH score was mainly designed for the diagnosis of pulmonary TB in
children and was once evaluated against pulmonary TB cases diagnosed by culture
and clinical features together; its sensitivity and specificity were 89% and 86%
respectively (21).
2.3
Specimen Recovery Methods
Gastric Lavage: Although rarely performed at BMC, three consecutive early
morning gastric lavages (GL) is the most common recovery method used to obtain
specimen for mycobacteriological confirmation in limited resource countries. In
addition to low culture yield, GL has many disadvantages:- specimens must be taken
on three sequential days early every morning before breakfast to achieve optimal
yields. Furthermore, the procedure itself is unpleasant for the child, semi invasive and
usually requires hospitalization as well as additional training of the staff. Therefore,
GL is difficult to be done on an outpatient basis where care for most TB suspected
children are usually provided. In addition, GL may not be optimal for collection of
these specific samples because it is known that a low pH kills tuberculous bacilli (22)
and this may affect the growth in subsequent culture media. In addition, peristalsis
movement in the evening and while the patient is sleeping makes it likely that many
of the TB organisms may have left the stomach by the time of specimen collection.
Sputum Induction: Sputum induction has been successfully used in several studies
as an alternative to GL to obtain specimen for microbiologic confirmation of PTB in
8
children. After pretreatment with an inhaled bronchodilator, nebulization with
hypertonic (3%–5%) saline is performed, and secretions are obtained by suctioning or
by expectoration in older children (8,11,23). Precautions must be taken to prevent
nosocomial transmission during sputum induction. The procedure should be
performed in a well ventilated room equipped with UV lighting or in the open air, and
sufficient time should be allowed between procedures (6). Appropriate particulate
respirators (N95 or FFP2) should be used by staff.
Sputum induction has been shown to be feasible, safe, and effective even in infants of
one month of age (8,11,23). Two studies involving hospitalized infants in a tertiary
care facility in South Africa successfully obtained samples from 95% of the children.
In the first study (8), one induced sputum sample yielded more positive culture results
(10% of samples) than three sequential GL samples (6% of samples), in the second
study (23), the cumulative yield from three induced sputum samples (87%) was
greater than that of three GL samples (65%). One induced sputum sample was
equivalent to three GL samples (23) and the yield was similar in both HIV infected
and HIV uninfected children.
Sputum induction has a number of advantages over GL as it can be performed as an
outpatient procedure, it is relatively easy to perform, and the yield is higher. The
remained challenge is to change the perception of health care workers that
microbiologic confirmation of PPTB is not possible and to implement sputum
induction as a routine investigative procedure in all health care facilities
Alternative Methods of Specimen Recovery: Alternative methods used for
specimen recovery include nasopharyngeal aspiration (NPA), bronchoalveolar lavage
9
(BAL) and string test to obtain stomach contents. NPA is achieved by passing a
canula through one nostril into the nasopharynx; it is minimally invasive and easy to
perform. A previous study done in Uganda suggested that the culture yield from NPA
was similar to that from sputum induction (24% vs 22%) (9). However, in two studies
from Yemen (24) and Peru (25) the culture yields from NPA were low.
BAL is a resource intensive and invasive procedure and therefore not recommended
for microbiologic confirmation of tuberculosis in resource limited settings. The string
test has not been well studied in a pediatric population and does not seem suitable for
young children.
2.4 Confirmation of Pulmonary TB in children
Confirmation of Mycobacterium tuberculosis (MTB) in pulmonary TB can be
performed by (direct or indirect) smear microscopy, by culture or by identification of
M. tuberculosis cellular components such as nucleic acid or cell wall component in
biological sample. The introduction of fluorescent microscopy with Auramine
staining has improved the sensitivity of microscopy and reduced operator time when
compared with traditional acid-fast stains, such as Ziehl-Neelsen. However, this
advance is unlikely to significantly improve the performance of smear microscopy
which currently detects only 10-15% of tuberculosis cases in children (26).
Sputum culture on solid media is the current reference standard for the confirmation
of pulmonary TB. Despite the high specificity which sputum culture can achieve in
the diagnosis of pulmonary TB if combined with a molecular speciation test, it is
thought to have relatively poor sensitivity (30% to 40%) when compared to a clinical
reference standard in children (26). The other limitations of the traditional culture
10
technique are slow turnaround time and the need for highly trained personnel, making
it difficult to use as a routine test in a setting with limited resources.
The current recommendation by WHO is that Xpert MTB/RIF assay may be used as
initial diagnostic test in all children suspected of having PTB and supports the use of a
single sputum specimen for diagnostic testing. The sensitivity of this test is better than
smear microscopy and is comparable to culture on solid media (27). In addition, it
simultaneously detects resistance to rifampicin which is a marker for MDR
tuberculosis. However, smear microscopy and culture remain essential for monitoring
of therapy for those who are on TB treatment and for monitoring MDR TB as it was
shown for adults, that Xpert MTB/RIF assay remains positive for a long time even in
successfully treated TB cases (28).
11
3.0
MATERIALS AND METHODS
3.1
Site Description
This study was conducted in the department of paediatric and child health at Bugando
Medical Centre, Tanzania. BMC is a consultant and teaching hospital for the Lake
and Western zones of the United Republic of Tanzania. Situated along the shores of
Lake Victoria in Mwanza, it has 900 beds and it serves both inpatient and outpatients.
It is a referral centre for tertiary specialist care for eight regions, including Mwanza,
Geita, Simiu, Mara, Kagera, Shinyanga, Tabora and Kigoma. It serves a catchment
population of approximately 13 million people.
The department of peadiatrics and child health has a capacity of 121 beds. The
department is subdivided into general peadiatric wards, malnutrition wards, semi
intensive care unit, neonatal unit, neonatal intensive care unit and outpatient
department.
3.2
Study design
A cross sectional hospital based study was conducted over a five-month period from
October 2013 to April 2014.
3.3
Sample size
Sample size was estimated using the Buderer’s formula (29), to determine the
sensitivity(SN) and specificity(SP) of 90% with absolute precision of less than 10% at
a 95% confidence interval [CI] with a 18.9% prevalence of PTB among TB suspects
in children(11).
12
Sample size (n) based
on specificity=
Z21−α/2 × SN ×(1−SN)
L2 × Prevalence
Sample size (n) based
on specificity =
Z21−α/2 × SP ×(1−SP)
L2 × (1−Prevalence)
where n = required sample size,
SN = anticipated sensitivity,
SP = anticipated specificity,
α = size of the critical region (1 – α is the confidence level),
z1-α/2 = standard normal deviate corresponding to the specified size of the critical
region (α)
L = absolute precision desired on either side (half-width of the confidence interval) of
sensitivity or specificity.
Based on the above formula the minimum sample size (n) was estimated to be 186
children suspected to have PTB.
3.4
Study Population
Children aged 2months to 12 years with respiratory TB symptoms as defined by
Graham et al (1) who were seeking care in the paediatric department of BMC, and
met the inclusion criteria were enrolled into the study.
Inclusion criteria
•
Written informed consent
•
Any one of the following:
ƒ
Persistent (> 2 weeks), non-remitting cough
13
ƒ
Persistent (> 1 weeks) and unexplained fever (380C)
ƒ
Unexplained weight loss/failure to thrive: 5% reduction in weight
compared with the highest weight recorded in last 3 months
ƒ
History of TB contact within the preceding 24 months
Exclusion criteria
3.5
•
Patient on TB treatment
•
Patient on Isoniazid Prophylaxis Treatment (IPT)
•
Known asthmatic or expiratory wheezes on auscultation
Data collection
3.5.1 Standard diagnostic procedures
The enrolment of the children suspected to have pulmonary TB included the delivery
of study information and obtaining an informed consent, the medical history of
participants, a physical examination with collection of detailed anthropometric data
such as middle upper arm circumference for children above 6 months (MUAC),
weight, and height. Furthermore HIV testing and chest radiography was part of the
enrolment visit.
All children aged 2 months to 12 years admitted to the peadiatric at wards were
screened for TB symptoms. Parents or guardians of those who fulfilled the criteria
were asked to consent for enrollment into the study. Children suspected to have PTB
who were referred from the outpatient clinic were also enrolled once they fulfilled the
eligibility criteria.
14
All enrolled children were re-assessed using the Keith Edward, MASA (30), IUATLD
or Fourie (20) and Brazilian MoH (31) diagnostic charts. Details of these TB score
charts are provided in appendix 5.
Chest X-Ray was taken in frontal view and was read by an independent radiologist who
was blinded to the study. A lateral view CXR was taken only when suggested by the
radiologist. CXR findings were reported in a standardized form with predetermined
terminology to describe CXR abnormalities (32) (Appendix 2). Chest X-rays were
defined as “consistent with tuberculosis” if there was a positive response for any one
of the radiological features.
A TST, using intradermal injection of 5 tuberculin units of purified protein derivative
(Mantoux) (TUBERSOL®, Sanofi Pasteur Limited, Canada), was performed by
trained personnel on the volar aspect of the left forearm. The transverse diameter of
induration was measured in millimetre after 48 to 72 hours. A positive TST was
regarded as a measurement of ≥10mm in HIV-uninfected children, and ≥ 5mm in
HIV-infected children (actual measurement in mm was recorded) (Appendix 6).
One sputum specimen was obtained by sputum induction (Appendix 4) which was
done by the investigator. A Pulmo – Mist II nebulizer (Nidek Medical, USA)
delivered 5 mL of 5% sterile saline solution for 10 to 15 minutes. Salbutamol solution
2.5mg was added to the nebulizer solution to prevent bronchoconstriction. Sputum
was obtained by suctioning through the nasopharynx with a sterile mucus extractor of
catheter size 7 or 8. Specimens were transported directly to the laboratory for
processing. New sterile disposable nebulizer masks, medication tanks and tubing were
used for each patient. Non disposable parts (tube connecting suction machine to
mucus trap) were cleaned and decontaminated after every use by submerging in 2%
15
glutaraldehyde for 20 minutes and allowed to air-dry. Data from a previous study
shows that parts of sputum induction equipment which are highly contaminated with
M. tuberculosis can effectively be decontaminated with glutaraldehyde (33).
Information about the HIV status was extracted from hospital patient files. Those with
no results were asked to have an HIV test, by using an HIV rapid test according to the
algorithm of the National HIV/AIDS guideline (Appendix 6.8). Information about
other diseases and tests not included in this study were extracted from BMC patient
files.
All admitted children were followed up for resolutions or persistence of TB symptoms
until discharge from hospital and then two months after being discharged through
phone calls. Children from the outpatient clinic were tellephonically followed up for
any treatment they were receiving for up to two months. During follow up, TB
symptoms (persistent cough, persistent fever, weight loss, etc) were specifically asked
for and those who were still experiencing symptoms after two months were advised to
come back to the clinic for re-assessment. No follow up was done after two months
and patients who were still experiencing symptoms were advised to continue follow
up and further workup through BMC outpatient clinic.
3.5.2 Laboratory procedures
All laboratory procedures were performed at the routine medical microbiology
laboratory of the Bugando Medical Centre.
Sputum specimens were processed for Fluorescent smear microscopy with Auramine
stain to detect AFB in sputum. Smear microscopy were read as follows; 1-9 AFB per
100 scanned fields were recorded in absolute number, 10-99 AFB per 100 scanned
16
fields were reported as (1+), 1-10 AFB per field scanned were reported as (2+) and
>10 AFB per field scanned as (3+). TB PCR (Xpert MTB/RIF assay) was also
performed on sputum samples when GeneXpert® MTB/RIF cartridges were available.
After microscopy and Xpert MTB/RIF assay, the remained sputum samples were
processed for LJ culture. At the beginning of this study we did not have LJ culture
media available, therefore all the samples collected from October to December (30
patients) and sputum samples collected from January to December (40 patients) were
stored at -200C for up to four weeks while waiting for LJ culture media to arrive.
Sputa were then decontaminated by modified Petroff’s methods using 4% sodium
hydroxide (NaOH) and then concentrated by centrifugation at 3000g. After
centrifugation it was cultured onto slopes of Lowenstein Jensen (LJ) medium with
glycerol (GLJ) and pyruvate (PLJ), and incubated at 37oC for 8 weeks. Each sputum
sample was inoculated in 2 LJ slopes. Culture slopes were inspected on weekly a
basis to observe growth.
3.5.3 Study duration and management of study subjects
Recruitment was done over a period of 5 months from October 2013 to April 2014.
All treatment decisions were taken independently of the study classification by the
clinicians who were taking care of the patient. However, laboratory study results were
made available to the attending clinicians in order to assist the treatment decision. In
the case of positive cultures, patients were called back after culture results to be
informed of their results and referred to the TB clinic for treatment, if TB treatment
had not yet been initiated.
17
3.6
Outcome of the study
The primary outcome of this study was defined as the number of microbiologically
confirmed TB cases. Secondary outcome was defined as the number of total TB cases
identified according to the diagnostic classification and the number of sputum
inductions performed.
3.7
Study Variables
Independent Variables
Dependent Variables
Age
Positive sputum culture
Sex
Positive sputum smear microscopy
TB contact
Positive Xpert MTB/RIF
HIV status
Positive TB score
Duration of TB symptoms
Weight for age
Weight for height/length
TST results
BCG vaccination/scar
Chest X-ray findings
3.8
Statistical analysis
Completed interview schedule was coded by numbers and entered into computer
software MS Excel 2007. Cross-checking and data cleaning was done. The data were
then transferred to STATA version 13 (Stata Corp, Inc., College Station, TX, USA)
software for analysis. Variables were summarized as proportions for categorical
variables and median with IQR for continuous variables. Associations between
18
variables were explored by logistic regression or Fischer’s exact test where
appropriate. All statistical tests were considered significant if the two sided P-value
(p) was <0.05. Sensitivity, specificity, positive predictive (PPV) value, and negative
predictive value (NPV) of Keith Edward score, MASA score, Fourie Score and
Brazilizn MOH score were calculated against pulmonary TB case by using 2–by–2
contingency table.
3.9
Data quality and assurance
The investigator interviewed and examined all patients. All information obtained from
the patients were recorded in structured questionnaires and kept in a hard cover file.
The files were stored by the investigator. Only the investigator and study team had
access to patient information. Questionnaires were then coded by numbers and
entered in computer software MS Excel 2007. Cross-checking and data cleaning were
done. During data cleaning and cross checking missing information were obtained by
going back to the structured questionnaires and lab results. The data were then
transferred to STATA version 13 (Stata Corp, Inc., College Station, TX, USA)
software for analysis.
3.10
Ethical consideration
Ethical clearance and approval were obtained from the joint CUHAS and BMC Ethics
review board. Written informed consent was obtained from parents/guardians of the
study participants. Witnessed oral consent was obtained from illiterate parents or
guardians in the presence of impartial witness. Confidentiality was assured and
unauthorized persons had no access to the collected data. Each study subjects was
19
assigned study identification number, which were kept confidential throughout the
study period.
20
4.0
RESULTS
4.1
Baseline Characteristics
From October 2013 to April 2014 a total of 1032 patients were screened for
enrollment in the study. Almost all screenings (98.4%) were inpatients admitted to the
general peadiatrics and malnutrition wards of BMC. A total of 197 (19.1%) children
were eligible for enrollment in the study. A total of 192 (97.5%) patients were
enrolled in the study; 5 (2.5% of all eligible patients) patients were excluded due to
unstable medical conditions which made it impossible to investigate the child and
perform induced sputum
Of the 192 children enrolled in the study. One hundred and three (53.7%) were male.
Median age among participants was 1.9 years (IQR 1.2 – 4.4). Only 4 (2.1%)
participants had a history of known TB contacts. Almost all children (92.7%) had
received BCG vaccination at birth. About half of the patients (49.5%) had severe
acute malnutrition. HIV test were positive in 15.1% of all participants while 9.4%
were HIV exposed children (Table 1).
21
Table 1: Baseline characteristics of study participants (n=192)
Characteristics
Number (%), Median [IQR]
Sex
Male
Age in years (Median)
Below 2years
2 years - <5 years
5 years and above
TB contact
Yes
No
Unknown
BCG vaccine
Yes
No
Unknown
Nutrition Status
Normal
Mild acute malnutrition
Moderate acute malnutrition
Severe acute malnutrition
Weight for age
Normal
Mild underweight
Moderate underweight
Severe underweight
TST Positive
HIV status
HIV positive
HIV exposed**
HIV negative
Unknown HIV status
Type of patients
Inpatient
Outpatient
103 (53.7)
1.9 [1.2 – 4.4]
100 (52.1)
47 (24.5)
45 (23.4)
4 (2.1)
176 (91.7)
12 (6.3)
178 (92.7)
13 (6.8)
1 (0.5)
48 (25.0)
25 (13.0)
24 (12.5)
95 (49.5)
38 (19.8)
33 (17.2)
28 (14.6)
93 (48.4)
22 (11.5)
29 (15.1)
18 (9.4)
129 (67.2)
16 (8.3)
175 (91.2)
17 (8.8)
**Children below 18 months of age who had positive HIV antibody test but not yet confirmed
by DNA PCR
22
Figure 1: Study flow diagram
1032 patients were screened for
enrollment into the study from
October 2013 to March 2014
1015 (98.4%) inpatients
17 (1.6%) outpatients
807 (78.2%) did not meet
eligibility criteria
28 (2.7%) died before being
screened
197 (19.1%) we eligible
for enrollment
5 (2.5%) excluded
because of critical
medical condition
192 (97.5%) enrolled in
the study
175 (91.1%) inpatients
17 (8.9%) outpatients
5 (2.6%) not tested
due to lack of sputum
sample
187 (97.4%) tested by
fluorescence microscopy
and by LJ culture
73 (39.1%) not tested due
to shortage of cartridges
114 (60.9%) tested
by Xpert MTB/RIF
assay
23
4.2
Specimen recovery
Sputum specimen was obtained in 187 (97.4%) patients. A single sputum induction
was successfully performed in (183) 95.8% patients, in 3 (1.6%) patients sputum
specimen was obtained by nasopharyngeal aspiration because they were not able to
tolerate the sputum induction procedure. Sputum specimens were not obtained in 5
(2.6%) patients. The average volume of sputum obtained was 2.4 mls (range 0.5 –
12). Epistaxis was the only adverse event reported among participants and was
experienced in 25 (13.4%) patients. Epistaxis stopped soon after the procedure
without any intervention in all cases. No serious complications occurred after the
procedure.
4.3
Common presenting symptoms
Cough, fever, and weight loss were the most common TB symptoms reported among
the participants with 96.6% (185 patients), 94.8% (182 patients) and weight loss
69.8% (134 patients) respectively. Hemoptysis constituting 0.3% (5 patients) was the
least symptoms reported (Figure 2).
24
Figure 2: Common presenting symptoms among patients enrolled in the study
Percent (Proportion) of patients
100
80
60
40
20
0
Cough
Night sweat
4.4
Fever
Weight loss
Fatigue
Difficulty in breathing
Chest pain
Hemoptysis
Radiological Characteristics
Chest X-ray in frontal view was obtained in all participants. One hundred and thirteen
(58.8%) had abnormal chest X-ray findings, of them 53 (46.9%) had findings
consistent with TB. Airspace opacification and hilar lymphadenopathy were the most
common radiological findings presenting in 27 (50.0%) patients and 20 (37.0%)
patients respectively in patients with features consistent with pulmonary TB. Airway
compression (1 patient) and vertebral spondylitis (1 patient) each constituting 1.8%
were the least reported radiological findings. Other radiological findings were miliary
pattern, pleural effusion and cavities which were present in 12 (22.2%), 11 (20.4%)
and 11 (20.4%) respectively.
25
4.5 Patients Follow-up
At enrollment 38 (19.8%) were eligible for initiation of TB treatment; 36 (94.7%) of
those who were eligible started on ant TB medication, 2 (5.3%) died before treatment
initiation, 1 (2.6%) had anti TB stopped after having alternative diagnosis confirmed.
At 2 months follow up 4 (2.1%) patients who were not on TB medication were found
eligible for TB treatment; 2 of them were started on TB treatment, 1 died and 1 was
lost to follow up.
There were 18 (9.4%) patients who died after enrollment; among those who died 7
(38.9%) patients were on TB treatment. At 2 months follow up there were 20 (10.4%)
deaths. All deaths occurred in patients who were admitted. Twenty three patients
(12.0%) were lost to follow up (Table 2).
Table 2: Follow up among patients enrolled in the study
PTB n (%)
No PTB n (%)
Total (%)
Two months follow up for previously admitted patients
No TB symptoms
22 (62.9)
100 (71.4)
122 (69.7)
2 (5.7)
11 (8.4)
13 (7.4)
10 (28.6)
10 (7.14)
20 (11.4)
Loss to f/u
1 (2.9)
19 (13.4)
20 (11.4)
Sub total
35 (100.0)
140 (100.0)
175 (100.00)
TB symptoms
Died
Two months follow up for patients referred from outpatients clinics
No TB symptoms
4 (80.0)
8 (66.7)
12 (70.6)
TB symptoms
1 (20.0)
1 (8.3)
2 (11.8)
Loss to f/u
0 (0.0)
3 (25.0)
3 (17.6)
Sub total
5 (100)
12 (100)
17 (100)
26
4.6
Yield for Mycobaterium tuberculosis from one induced sputum
Sputum was obtained from 187 (97.4%) patients. There were 10 (5.3%) patients
whom PTB were confirmed by culture and/or Xpert MTB/RIF assa. Yield for MTB
was 1.1%, 4.3% and 2.6% from sputum smear microscopy, sputum culture and Xpert
MTB/RIF assay respectively (Table 3).
Among patients who had bacteriological confirmation of pulmonary TB, 1 patient had
confirmation by both positive culture and Xpert MTB/RIF assay, 2 patients had
confirmation by positive Xpert MTB/RIF assay while culture was negative, and in the
remaining 7 patients confirmation was by positive culture alone. Half (4 patients) of
those with positive culture had no GeneXpert performed. Fluorescent AFB smear was
positive in 2 patients among them one had both positive culture and positive Xpert
MTB/RIF assay while the other had positive culture and GeneXpert not performed.
Table 3: Yield for MTB from one induced sputum among patients enrolled in the
study
Positive cases
Total
n (%)
Sputum smear
187
2 (1.1)
Culture
187
8 (4.3)
Xpert MTB/RIF
114
3 (2.6)
4.7
The proportion of PTB cases
The overall proportion of pulmonary TB cases was 20.8% (40 patients) among
patients who were enrolled in the study. The proportion of confirmed Pulmonary TB
was 5.2% (10 patients). There were 10 (5.2%) with probable PTB and 20 (10.4%)
patients with possible PTB.
27
About 64% of all the patients had a score suggestive of likey TB based on Fourie
score, 22.9% of the patients had likely TB based on Keith Edward score while very
few (3.6%) had a score suggestive of suspected TB by MASA score (Table 4).
Table 4: TB cases based by Peadiatrics TB score charts and Diagnostic
classification among patients enrolled in the study (N = 192)
n (%)
Keith Edward Score
TB Likely
44 (22.9)
TB Unlikely
148 (77.1)
MASA score
Suspected TB
7 (3.6)
Not suspected TB
185 (96.4)
TB likely
122 (63.5)
Fourie
TB unlikely
(36.5)
Brazilian MOH score
Very likely PTB
14 (7.3)
Possible PTB
42 (21.9)
Unlikely PTB
136 (70.8)
Diagnostic Classification
4.8
Confirmed PTB
10 (5.2)
Probable PTB
10 (5.2)
Possible PTB
20 (10.4)
Unlikely PTB
37 (19.3)
No TB
115 (59.9)
Sensitivity, Specificity, & Positive/Negative predictive values
All scores showed low sensitivity against microbiologically confirmed PTB case
(10% - 50%). MASA scores showed higher specificity of 97.2% but lowest
sensitivity, Fourie score showed very low specificity of 34.5%. Positive predictive
28
values (4.1 – 16.7%) were very low for all scores; negative predictive values (NPV)
ranged from 92.4% to 96.3% for all scores (Table 5).
Table 5: Sensitivity, specificity, PPV and NPV of TSCs against microbiologically
confirmed pulmonary TB
Positive TB
Confirmed
Sv (%)
Sp (%)
PPV (%)
NPV (%)
Score Charts
TB case
(n=10)
Keith
Edward
02
20.0
76.2
4.6
94.4
MASA
01
10.0
97.2
16.7
95.5
Fourie
05
50.0
34.5
4.1
92.4
Brazilian
MOH
05
50.0
73.5
9.6
96.3
Sv = Sensitivity; Sp = Specificity; PPV = Positive predictive value; NPV = Negative predictive values.
The calculations were based on a total 187 patients whom sputum samples were obtained.
4.9 Factors associated with microbiologically confirmed PTB
There were no baseline characteristics which had significant association with
confirmed pulmonary TB (Table 6).
Airspace opacification, cavities and vertebral spondlytis on chest X-ray were
significantly associated with confirmed pulmonary TB with p-values of <0.01, 0.01
and 0.05 respectively (Table 7). In addition, chest X-ray with any finding consistent
with pulmonary TB was significantly associated with confirmed pulmonary TB case.
29
Table 6: Baseline characteristics associated with confirmed TB among patients
enrolled in the study
P-value
Characteristics
Confirmed TB (%) No TB (%)
Sex
Male
4 (40.0)
97 (54.8)
0.52
Female
6 (60.0)
80 (45.2)
Age (years)
< 5 years
8 (80.0)
40 (22.6)
1.00
≥ 5 years
2 (20.0)
137 (77.4)
TB contact
Yes
1 (10.0)
3 (1.7)
0.20
No
9 (90.0)
165 (98.3)
BCG vaccine
Yes
9 (90.0)
165 (93.2)
No
1 (10.0)
11 (6.2)
0.52
Unknown
0 (0.0)
1 (0.6)
Nutrition status
Severe malnutrition
5 (50.0)
88 (49.7)
1.00*
No severe malnutrition 5 (50.0)
89 (50.3)
Weight for age
Severe underweight
4 (40.0)
86 (48.6)
0.75
No severe underweight 6 (60.0)
91 (51.4)
TST
Positive
3 (30.0)
18 (10.2)
0.09
Negative
7 (70.0)
159 (89.8)
HIV status
Positive
1 (10.0)
27 (27.2)
Negative
7 (70.0)
118 (66.7)
1.0
HIV exposed
1 (10.0)
17 (9.6)
Unknown status
1 (10.0)
15 (8.5)
*p-value was calculated by chi-square test. In all other variables p-values were calculated by
Fischer’s exact test.
30
Table 7: Radiological features associated with confirmed Pulmonary TB among patients enrolled
in the study (N = 187)
Characteristics
Confirmed TB (%)
n = 10
No TB (%)
n = 177
P-value*
Airway compression
0 (0.0)
1 (0.6)
1.00
Hilar lymphadenopathy
2 (20.0)
16 (9.0)
0.25
Airspace opacification
6 (60.0
27 (15.3)
<0.01
Miliary
1 (10.0)
10 (5.7)
0.46
Cavities
3 (30.0)
6 (3.4)
0.01
Pleural effusion
1 (10.0)
9 (5.1)
0.43
Vertebral spondylitis
1 (10.0)
0 (0.0)
0.05
CXR consistent with PTB
7 (70.0)
43 (24.3)
<0.01
*p-value was calculated by Fischer’s exact test
31
5.0
DISCUSSION
In this study, which included 192 pulmonary TB suspected children, we evaluated the
performance of four pediatric score charts for the diagnosis of pulmonary TB, to
bacteriological confirmation in culture or Xpert MTB/Rif assay performed on induced
sputa. These scores and many other scores were designed to be used in developing
countries with high TB prevalence and limited resources. Most of these scores were
designed during a time when HIV was less prevalent and it were shown to be useful
when used in HIV negative population (17).
5.1
Sputum Induction as a method of specimen recovery method
This study has shown that sputum induction is feasible and safe for the diagnosis of
pulmonary TB in our setting. It is less invasive, needs little specific equipment and is
easy to perform. Furthermore, it can be done on outpatient basis although almost all of
the patients in this study (91%) were inpatients. About 95% of patients in this study
were successfully induced and no serious adverse effects occurred. Mild epistaxis
occurred in 25 (13.5%) patients, which was consistent with one other study, where
epistaxis was mostly observed in patients who had sputum aspirated through the
nasopahrynx instead of expectoration after sputum induction (34).
The yield from LJ culture was 4.3% and that from Xpert MTB/RIF assay and
fluorescent AFB smear microscopy were 2.6% and 1.1%, respectively. Although the
yield from culture has been shown to be higher compared to Xpert MTB/RIF assay in
other studies (8,23,34), it is difficult to compare the yield between culture and Xpert
MTB/RIF assay in this study because Xpert MTB/RIF assay was not performed in all
32
patients; about half (4 patients) of those with positive culture had no GeneXpert assay
performed.
5.2
Proportion of patients who had pulmonary tuberculosis
Forty patients (20.8%) were diagnosed to have pulmonary TB based on their
diagnostic classification (confirmed TB, probable TB and possible TB). The
proportion of patients who had confirmed pulmonary TB (5.2%) was very low, if
compared with other studies in different setting. In this study, where we were trying to
determine the sensitivity of various pediatric score charts, we decided to choose very
sensitive inclusion criteria in order not to miss those with mild forms of pulmonary
TB, who could easily be missed by many scores. Therefore, by being more sensitive
our inclusion criteria also could have allowed many patients who did not have TB to
enter the study with the consequence of having a low yield in sputum culture or Xpert
MTB/RIF assay. Our patients had a high rate of severe acute malnutrition (50%) and
HIV (15%), which also could easily confound with performance of test for
tuberculosis diagnosis. A previous study in Uganda (9), where they used very strict
inclusion criteria (Positive TST and chest X-ray consistent with PTB), the proportion
of patients with confirmed TB was 27.3%. However, a recent study (11) done in the
same setting where severe pneumonia was used as an eligibility criteria, the rate of
confirmed TB dropped to 6.3% which is comparable with the 5.2% which we found in
our study,.
A singe sputum sample was collected in our study, compared to other studies
(8,9,23,34) were multiple samples were collected on 2 or 3 consecutive days, which
certainly would have maximized the yield. A very recent study in Botswana (35),
33
where also only one sample was collected, the proportion of confirmed TB was 6%
which is again comparable with our findings. Sputum sample for about half of the
participants in this study were frozen at -200C for up to 4 weeks while waiting for
arrival of new LJ culture media; this also would have minimized the yield.
5.3
Sensitivity and specificity of the TSCs
The sensitivity of all four peadiatric TSC evaluated in this study is very low. Keith
Edward, the TSC that is commonly used in our setting, has a sensitivity of 20.0%
which is much lower than previously reported from Zambia (14). The MASA score
had a sensitivity of 10.0% which is very low and could be explained by the fact that it
needs a triad of suggestive TB symptoms, CXR consistent with TB as well as a
positive TST which is a limiting factor in our setting with a high rate of HIV and
severe malnutrition.
The Fourie score, which was originally designed for screening purposes to identify
TB suspects to be referred for further examination (20), showed a sensitivity (50%) in
comparison to other scores. It was designed with less strict criteria, probably to make
it more sensitive as a screening tool, but the sensitivity of 50% is still unsatisfactory.
Although it has shown a fair NPV, its specificity and PPV are too poor to make it
useful for diagnostic purposes.
There was a wide variation in the specificity of the four scores; the MASA score
showed a high specificity (97%) and a good NPV (95%) which makes it a useful tool
to exclude PTB. However, the demonstrated very low sensitivity and PPV (16.7%)
makes it a poor diagnostic test. The Keith Edward score had a specificity and NPV of
76.2% and 94.4%, respectively, which makes it useful in the confirmation or
34
exclusion of PTB. Sensitivity and PPV were low the overall performance of the score
could be improved if radiological criteria (CXR) were included as one of the
components to diagnose pulmonary TB.
The Brazilian MOH score was designed mainly for the diagnosis of pulmonary TB in
outpatients in Brazil (21,31). In our study it demonstrated a low sensitivity (50%) and
PPV (9.6%), and a fair specificity of 73.5% with good NPV (96.3%). However,
although most of our study participants were inpatients, we had expected this score to
perform better than the other three scores.
The observed big differences between these scores in our study might be attributed to
the fact that most of these scores were designed to screen for both pulmonary and
extra pulmonary TB. Extrapulmonary TB is known to be common among children
(36,37), and can not be confirmed without culture and/or PCR of blood, urine, stool
and histologic samples of appropriate organs. We were not able to perform these
additional investigations in our study and are therefore not surprised that some cases
of TB that were noted to be likely or probable by TB scoring systems were not
confirmed by micrological examination of the sputum. Further studies are needed to
determine the burden of extrapulmonary TB among children in our setting.
5.4
Factors associated with confirmed TB
Diagnosis of pulmonary TB in children is always difficult due to the non specific
nature of symptoms and the fact that bacteriological confirmation is not always
possible due to the low bacilli load in childhood TB. In this study we found no
baseline characteristics which were significantly associated with microbiologically
confirmed TB cases. Chest X-ray finding consistent with pulmonary TB had
35
significant association with microbiologically confirmed TB (p-value <0.01). I
addition, cavitation and airspace opacification were the specific radiological features
which showed significant association with microbiologically confirmed TB (p-values
0.01 and <0.01 respectively). In another study (38), it was found that cavitations and
hilar lymphadenopathy had a significant association with confirmed TB. This is
important as Chest X-ray findings are not included in the score that is used in our
setting. The justification for the choice of this score chart was that Chest X-rays are
expensive and not readily available. However, this does not apply today where Chest
X-rays are obtainable in many hospitals in limited resource setting. Our findings
advocate the inclusion of Chest X-rays as one of the score criteria in order to improve
its performance.
36
6.0
CONCLUSIONS
•
Sensitivity and specificity of peadiatric tuberculosis score charts evaluated in
this study perform poorly for the detection of pulmonary TB and there were
wide variations among the scores.
•
Bacteriological confirmation of pulmonary tuberculosis in children is possible
in our setting and may be useful in detecting drug sensitive or resistant TB.
•
Sputum induction for obtaining sputum has shown to be useful and safe for
mycobateriological confirmation of pulmonary tuberculosis in children in our
setting.
•
Chest X-ray findings consistent with pulmonary TB have shown to be
significantly associated with microbiologically confirmed pulmonary TB;
hence Chest X-ray findings should be included in tuberculosis score charts.
37
7.0
RECOMMENDATIONS
•
Bacteriological confirmation of pulmonary TB should be attempted in every
child presenting with TB symptoms.
•
Sputum induction should be emphasized and all clinicians should be trained
on how to perform it, as it has shown to be easy, safe and useful in obtaining
samples for bacteriological confirmation of pulmonary TB in children. Future
studies should evaluate the benefit of inducing more than 1 sputum sample.
•
Chest X-ray components should be incorporated in all pediatrics TSCs,
especially in the score chart recommended for our setting. Radiological
features such as cavities and airspace opacity have shown to have significant
association with PTB in our study. Inclusion of chest X-ray findings might
improve the performance of these scores.
•
Further studies are needed to determine the prevalence of extrapulmonary TB
among children in Tanzania and whether the pediatric TB scoring systems are
useful in diagnosing these children.
38
8.0
LIMITATIONS OF THE STUDY
This is a single-centre study and may not be generalizable to other healthcare settings.
The TSCs that were evaluated in this study were designed for different purposes;
some such as Keith Edwards were designed for the diagnosis of both pulmonary and
extra pulmonary TB, while others such as the Brazilian MOH were designed for the
diagnosis of mainly pulmonary TB. The Fourie score was designed as a screening tool
to identify patients for further TB work up. Therefore, the diversity of the results is no
doubt at least partly due to the different intentions of the TSCs.
Because this was the first time that sputum induction was performed at BMC, only
one induced sputum sample was collected for each patient. Performance of only one
induced sputum sample may have lead to an underdiagnosis of pulmonary TB.
Investigations in this study focused on pulmonary tuberculosis, there may have been a
bias against diagnostic scores that included features of extra-pulmonary tuberculosis.
39
9.0
REFERENCES
1.
Graham SM, Ahmed T, Amanullah F, et al. Evaluation of tuberculosis
diagnostics in children: 1. Proposed clinical case definitions for classification
of intrathoracic tuberculosis disease. Consensus from an expert panel. J Infect
Dis. 2012 May 15;205 Suppl(Suppl 2):S199–208.
2.
WHO. The global plan to stop TB 2006-2015 : Progress Report 2006-2008.
3.
WHO. Guidance for National Tuberculosis Programmes on the management of
tuberculosis in children. Chapter 1: introduction and diagnosis of tuberculosis
in children. Int J Tuberc Lung Dis. 2006 Oct;10(10):1091–7.
4.
Mtabho CM, Irongo CF, Boeree MJ, et al. Childhood tuberculosis in the
Kilimanjaro region: lessons from and for the TB programme. Trop Med Int
Heal. 2010 May;15(5):496–501.
5.
Praygod G, Todd J, McDermid JM. Early childhood tuberculosis in
northwestern Tanzania. Int J Tuberc Lung Dis. 2012 Nov;16(11):1455–60.
6.
Connell TG, Zar HJ, Nicol MP. Advances in the diagnosis of pulmonary
tuberculosis in HIV-infected and HIV-uninfected children. J Infect Dis. 2011
Nov 15;204 Suppl(Suppl 4):S1151–8.
7.
Eamranond P, Jaramillo E. Tuberculosis in children: reassessing the need for
improved diagnosis in global control strategies. Int J Tuberc Lung Dis. 2001
Jul;5(7):594–603.
8.
Zar HJ, Tannenbaum E, Apolles P, et al. Sputum induction for the diagnosis of
pulmonary tuberculosis in infants and young children in an urban setting in
South Africa. Arch Dis Child. 2000 Apr;82(4):305–8.
9.
Owens S, Abdel-Rahman IE, Balyejusa S, et al, Parry CM, et al.
Nasopharyngeal aspiration for diagnosis of pulmonary tuberculosis. Arch Dis
Child. 2007 Aug;92(8):693–6.
10.
Chang KC, Leung CC, Yew WW, Tam CM. Supervised and induced sputum
among patients with smear-negative pulmonary tuberculosis. Eur Respir J.
2008 May;31(5):1085–90.
11.
Nantongo JM, Wobudeya E, Mupere E, et al. High incidence of pulmonary
tuberculosis in children admitted with severe pneumonia in Uganda. BMC
Pediatr. 2013 Jan;13(1):16.
12.
Azzopardi P, Graham S. What are the most useful clinical indicators of
tuberculosis in childhood ? Int Child Heal Rev Collab. 2008;1–8.
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13.
Hesseling AC, Schaaf HS, Gie RP, et al. A critical review of diagnostic
approaches used in the diagnosis of childhood tuberculosis. Int J Tuberc Lung
Dis. 2002;6(August):1038–45.
14.
Van Rheenen P. The use of the paediatric tuberculosis score chart in an HIVendemic area. Trop Med Int Heal. 2002 May;7(5):435–41.
15.
Edwards DJ, Kitetele F, Van Rie A. Agreement between clinical scoring
systems used for the diagnosis of pediatric tuberculosis in the HIV era. Int J
Tuberc Lung Dis. 2007 Mar;11(3):263–9.
16.
Brändli O. The clinical presentation of tuberculosis. Respiration. 1998
Jan;65(2):97–105.
17.
Narayan S, Mahadevan S, Serane VT. Keith Edwards score for diagnosis of
tuberculosis. Indian J Pediatr. 2003 Jun;70(6):467–9.
18.
Sarkar S, Paul DK, Chakrabarti S, Mandal NK, Ghoshal a G. The Keith
Edward scoring system: A case control study. Lung India. 2009 Apr;26(2):35–
7.
19.
Marais BJ, Gie RP, Hesseling AC, et al. A refined symptom-based approach to
diagnose pulmonary tuberculosis in children. Pediatrics. 2006
Nov;118(5):e1350–9.
20.
Fourie PB, Becker PJ, Festenstein F, et al. Procedures for developing a simple
scoring method based on unsophisticated criteria for screening children for
tuberculosis. Int J Tuberc Lung Dis. 1998 Feb;2(2):116–23.
21.
Anna CCS, Orfaliais CTS, March MDFP, Conde MB. Evaluation of a proposed
diagnostic scoring system for pulmonary tuberculosis in Brazilian children. Int
J Tuberc Lung Dis. 2006;10(October 2005):463–5.
22.
Jackett PS, Aber VR, Lowrie DB. Virulence and resistance to superoxide, low
pH and hydrogen peroxide among strains of Mycobacterium tuberculosis. J
Gen Microbiol. 1978 Jan;104(1):37–45.
23.
Zar HJ, Hanslo D, Apolles P, et al. Induced sputum versus gastric lavage for
microbiological confirmation of pulmonary tuberculosis in infants and young
children: a prospective study. Lancet. 2005;365(9454):130–4.
24.
Al-Aghbari N, Al-Sonboli N, Yassin M a, et al. Multiple sampling in one day
to optimize smear microscopy in children with tuberculosis in Yemen. PLoS
One. 2009 Jan;4(4):e5140.
25.
Oberhelman RA, Soto-Castellares G, Gilman RH, et al. Diagnostic Approaches
For Paediatric Tuberculosis By Use Of Different Specimen Types, Culture
Methods, And Pcre. Lancet Infect Dis. 2011 Oct;10:612–20.
41
26.
Zar HJ, Connell TG, Nicol M. Diagnosis of pulmonary tuberculosis in children:
new advances. Expert Rev Anti Infect Ther. 2010 Mar;8(3):277–88.
27.
Automated real-time nucleic acid amplification technology for rapid and
simultaneous detection of tuberculosis and rifampicin resistance: Xpert
MTB/RIF assay for the diagnosis of pulmonary and extra- pulmonary TB in
adults and children. Policy update. World Heal Organ. 2013;
28.
Friedrich SO, Rachow A, Saathoff E, et al. Assessment of the sensitivity and
specificity of Xpert MTB/RIF assay as an early sputum biomarker of response
to tuberculosis treatment. lancet Respir Med. Elsevier Ltd; 2013 Aug;1(6):462–
70.
29.
Malhotra RK, Indrayan A. A simple nomogram for sample size for estimating
sensitivity and specificity of medical tests. Indian J Ophthalmol.
2007;58(6):519–22.
30.
Hatherill M, Hanslo M, Hawkridge T, et al. Structured approaches for the
screening and diagnosis of childhood tuberculosis in a high prevalence region
of South Africa. Bull World Heal Organ. 2010 Apr;88(4):312–20.
31.
Sant’Anna CC, Santos MARC, Franco R. Diagnosis of pulmonary tuberculosis
by score system in children and adolescents: a trial in a reference center in
Bahia, Brazil. Braz J Infect Dis. 2004 Aug;8(4):305–10.
32.
Marais BJ, Gie RP, Schaaf HS, et al. A proposed radiological classification of
childhood intra-thoracic tuberculosis. Pediatr Radiol. 2004 Aug 5;34(11):886–
94.
33.
French ML, Dunlop SG, Wetzler TF. Contamination of sputum induction
equipment during patient usage. Appl Microbiol. 1971 May;21(5):899–902.
34.
Planting NS, Visser GL, Nicol MP, et al. Safety and efficacy of induced
sputum in young children hospitalised with suspected pulmonary tuberculosis.
Int J Tuberc Lung Dis. 2014 Jan;18(1):8–12.
35.
Joel DR, Steenhoff a P, Mullan PC, et al. Diagnosis of paediatric tuberculosis
using sputum induction in Botswana: programme description and findings. Int J
Tuberc Lung Dis. 2014 Mar;18(3):328–34.
36.
Pavan Kumar N, Anuradha R, Andrade BB, et al. Circulating biomarkers of
pulmonary and extrapulmonary tuberculosis in children. Clin Vaccine
Immunol. 2013 May;20(5):704–11.
37.
Swaminathan S, Rekha B. Pediatric tuberculosis: global overview and
challenges. Clin Infect Dis. 2010 May 15;50 Suppl 3(Suppl 3):S184–94.
42
38.
Garcia SB, Perin C, Silveira MM da, et al. Bacteriological analysis of induced
sputum for the diagnosis of pulmonary tuberculosis in the clinical practice of a
general tertiary hospital. J Bras Pneumol. 2009 Nov;35(11):1092–9.
43
10.0
APPENDICES
44
10.1
Data Collection Form
Medical History Form
File number
|___|___|___||___|___|___|
Study ID
Date of Interview (DD/MM/YYYY)
|___|___|___|
|___|___| |___|___| |___|___|___|___|
Date of Birth (DD/MM/YYYY)
Initials of Participant
|___|___|___| (initials of first name, |___|___| |___|___| |___|___|___|___|
middle name, sir name) or Age
Sex |______|M/F
Years: |___|___| Months: |___|___|
1. TB contact
Has the participant had any known TB contact in the last two years?
1□ yes 2□ no 9□ unknown
Was this TB contact
1□sputum smear positive
2□sputum smear negative
9□unknown
Was this TB contact treated for TB?
1□yes
2□no
9□ unknown
2. Present symptoms
Has the participant got any of the Duration of the last episode:
following symptoms at the moment? 1 = 1-7 days
2 = 8-14 days
(Multiple answers possible
3 = 15-27 days
4 = 1-3 months
5 = > 3 months
Cough
1□yes
2□no
9□unknown
Fatigue/lethargy
1□yes
2□no
9□unknown
Difficulty in breathing
1□yes
2□no
9□unknown
Fever
1□yes
2□no
9□unknown
Chest pain
1□yes
2□no
9□unknown
Night sweat
1□yes
2□no
9□unknown
45
Haemoptysis
1□yes
2□no
9□unknown
Weight loss over last month
1□yes
2□no
9□unknown
Other symptomPlease specify:
____________________________
3. Past medical history
Has the participant ever been tested for
1□yes 2□no 9□unknown
TB?
If yes, when was the last TB test?
1□ During the last 3 months
2□ During the last 12 months
3□ Other____________________
If yes, which tests were performed? 1□ clinical examination
2□ chest X-ray
(multiple answers possible) 3□ sputum
4□ TST
5□ others, specify ________________________
6□ no tests done
9□ unknown
Has the participant ever been diagnosed
1□yes 2□no 9□unknown
of having TB?
1□ during the last 3 months
If yes, when was the participant
2□ during the last 12 months
diagnosed of having TB?
3□ other____________________
Was the participant ever diagnosed of
1□yes 2□no 9□unknown
having HIV?
1□ during the last 3 months
If yes, when was the participant first
2□ during the last 12 months
tested being HIV positive?
3□ other____________________
Did the participant ever receive a BCG
1□yes 2□no 9□unknown
vaccination? (Check for BCG scar)
46
Clinical Examination Form
Weight |___|___|, |___|kg
Height |___|___|___|, |___| cm
MUAC |___|___|, |___| cm
Temperature |___|___|, |___| °C
for children above 6 months of age
Respiratory rate ________ / min
Pulse rate ________ / min
TST 1□ applied TST 2□ not applied
If TST apllied please give the following information:
Date of test (DD/MM/YYYY)
|___|___| |___|___| |___|___|___|___|
Result (48‐72h) |___|___| mm
General Appearance
General condition
1□
good
2□ reduced
Pallor/anaemia
1□ yes
2□ no
Dehydration 1□ yes
2□ no
Weight for age (%)
1□ > 90
2□ > 80
3□ 60 – 80
3□ ill
4□ critically ill
4□ < 60
Weight for height/length
1□ No malnutrition
2□ Mild milnutrition
3□ Moderate malnutrition
4□ Severe malnutrition
Lympadenopathy
1□ yes
2□ no
If yes, please specify: 1□ Cervical
(multiple answers)
2□ Sub mandibular
3□ Supra clavicular
4□ Axillary
5□ Inguinal
6□ Others _______________
Others
Specify
_______________________________________________
47
Respiratory system
Any abnormal finding
Dyspnoea
(multiple answers possible)
Percussion abnormal
(multiple answers possible) Auscultation
abnormal
(multiple answers possible)
Others abnormalities
1□ yes
2□ no
1□ yes
2□ no
1□ yes
2□ no
1□ yes
2□ no
Specify
_______________________________________________
Abdominal system
Any abnormal finding
1□ yes
Abdominal tenderness?
Specify
location 1□ yes
____________
Distension 1□ yes
2□ no
2□ no
2□ no
Ascites
1□ yes
2□ no
Palpable mass
1□ yes
2□ no
Hepatomegaly
1□ yes
2□ no
Others abnormalities
Specify
_______________________________________________
Nervous system
Any abnormal finding
1□ yes
2□ no
Alert
1□ yes
2□ no
Lethargic/drowsy
1□ yes
2□ no
Unconscious
1□ yes
2□ no
Confused
1□ yes
2□ no
Abnormal muscle tone
1□ yes
2□ no
Neck-stiffness
1□ yes
2□ no
Anterior fontanelle
1□closed / normal
Others abnormalities
Specify
_______________________________________________
48
2□bulging
3□sunken
Skeletal system
Any abnormal finding
1□ yes
If yes, specify:
1□ Joint pains
location: ______________
2□ Swelling of joint
location: ______________
3□ Joint deformity
location: ______________
4□ others
please specify: __________________________
2□ no
Other affected System
Any abnormal finding
1□ yes
2□ no
If yes, specify:
Chest X –Ray report
Any abnormal finding
1□ normal
2□ abnormal (see CXR report)
49
10.2
Standardized Chest X-ray Review Tool
Study ID
Date of X-Ray (DD/MM/YYYY)
|___|___|___|
|___|___| |___|___| |___|___|___|___|
Date of Birth (DD/MM/YYYY)
Initials of Participant
|___|___|___| (initials of first name, middle |___|___| |___|___| |___|___|___|___|
name, sure name) or Age
Sex |______|M/F
Years: |___|___| Months: |___|___|
Instructions:
Tick only one of ‘Yes’ or ‘No’ or ‘Not Visible’ for each category of abnormality identified
(numbered 1 – 8).
1. Airway compression and/or
tracheal displacement
Yes
No
Not Visible
If yes, specify location:
3. Air space opacification
Yes
No
Not Visible
If yes, specify location:
5. Pleural effusion
Yes
No
If yes, specify location:
Not Visible
4. Nodular picture = Miliary or large
widespread and bilateral
Yes
No
Not Visible
If yes, specify location:
6. Calcified parenchyma (Ghon focus)
Yes
No Not Visible
If yes, specify location:
7. Cavities
Yes
No
If yes, specify location:
Not Visible
8. Vertebral spondylitis
Yes
No
Not Visible
If yes, specify location:
Technical quality
AP view
Lateral view
2. Soft tissue density suggestive of
lymphadenopathy
Acceptable
Acceptable
Yes
No
If yes, specify location:
Poor but readable
Poor but readable
50
Not Visible
Not acceptable not readable
Not acceptable not readable
Definition:
Chest X-ray will be defined as “consistent with tuberculosis” if there is a
positive response for any 1 of the radiological features, at the same location,
by at least 2 expert reviewers.
51
10.3
Information Sheet and Informed Consent Form
10.3.1 Information Sheet and Informed Consent Form
Study ID No _____________
You are invited to participate in a research study on “Evaluation of Paediatric
Tuberculosis Score Chart against Smear Microscopy and Culture from Induced
Sputum among children PTB suspects at Bugando Medical Centre”. You have been
asked to participate because your child has been found with symptoms of TB disease. We
ask that you read this form and ask any questions you may have before agreeing to
participate in this study.
I Dr. Issa Sabi am going to conduct the study as a partial fulfillment of master of medicine
degree course of CUHAS-Bugando. The study is funded by MoHSW of Tanzania and is
planned to enroll 235 children. The study proposal has been approved by the ethics and
research committee of CUHAS – Bugando.
Study Purpose
The purpose of this study is that diagnosis of TB in children is difficult because children do
not have ability to produce sputum for confirmation of TB disease. Currently at BMC the
diagnosis of TB in children is made using peadiatrics TB score chart which check for the
presence of clinical symptoms and signs. This may cause problems especially in areas of
high rate of HIV infection because many symptoms due to TB disease are similar with
symptoms and signs due to HIV related infections and other disease of the respiratory
system. This may results in incorrect diagnosis of TB in children.
52
Therefore, this study will evaluate the performance of peadiatrics TB score charts in
diagnosis of TB of the lungs in comparison to sputum microscopy and culture performed on
induced sputum. This will not in any way affect the way you will be managed in the ward.
Study Procedures
Before you enter the study we will check whether you fulfill the criteria to enter the study.
The procedure will involve us asking you about your child’s HIV infection status,
performing Tuberculin Skin Testing and chest x-ray. These are important tests for any
patient suspected of Tuberculosis.
Sputum will be induced by inhaling nebulized fluids which will cause the child to produce
and cough out sputum. TB PCR (GeneXpert) will also be performed although results of the
test will not be part of this project.
Risks of Participation in the Study
Inhaling nebulized fluid for sputum induction can very rarely cause shortness of breath,
which will be treated by the study investigator/doctors and is not dangerous.
Benefits of Participation in the Study
There will be no direct benefits to you from this study. However, information obtained from
this study may be of benefits to the community because will improve the diagnosis of TB in
children.
Confidentiality
In this study all information will be kept private. In any publications or presentations, we
will not include any information that will make it possible to identify your child as a
subject.
53
Right to Withdrawal
Participation in this study is voluntary. You have the right to withdrawal from the study at
any time if you decide to do so and you do not have to give reason. Your decision of
whether or not to participate in this study will not affect your relationship with the research
team. If you decide to participate, you are free to withdraw at any time without affecting
those relationships, or diagnosis or treatment you will receive.
Contacts and Questions
This study is headed by Dr. Issa Sabi, CUHAS – Bugando (Study investigator). You may
ask any question you have now. If you will have questions later, or in the event of study
related injury you are encouraged to contact him at: Dr. Issa Sabi, P.O.Box 1464 Mwanza,
Tell: +255 713 558722
Statement of Consent
I have read the above information. I have asked questions and have received answers. I
consent to participate in this study.
NAME……………………………………… FILE NUMBER………………………………
Participant’s name
NAME………………………………....SIGNATURE…………………….DATE………….
Parent/guardian
NAME…………………………………SIGNATURE…………………….DATE…………
Witness
NAME…………………………………SIGNATURE…………………….DATE………….
Study Investigator
54
10.3.2 Karatari ya maelezo na form ya ridhaa
Nambari ya utafiti _____________
Unakaribishwa kushiriki katika utafiti kuhusu “Tathmini ya chati za alama za kifua
kikuu cha watoto (Peadiatrics TB score chart) dhidi ya kupimo cha makohozi kwa
hadubini na kuotesha kwenye makohozi yaliyozalishwa kwa kuvuta mvuke wa maji ya
chumvi miongoni mwa watoto wanaodhaniwa kuwa na kifua kikuu katika hospitali ya
Bugando”. Umeombwa ushiriki kwasababu mtoto wako amekutwa na dalili za kifua kikuu.
Tunaomba usome hii fomu na uulize maswali yoyote uliyonayo kabla ya kukubali kushiriki
kwenye huu utafiti.
Mimi Dkt. Issa Sabi nitafanya utafiti huu ikiwa ni moja ya mahitaji katika kukamilisha
shahada ya udhamiri ya udaktari was binadamu ya CUHAS-Bugando. Utafiti huu
unagharamiwa na wizara ya afya na usitawi wa jamii ya Tanzania na utahusisha watoto
wasiopungua 235. Utafiti huu umeidhinishwa na kamati ya maadili na utafiti ya CUHASBugando.
Dhumuni la utafiti
Dhumuni la utafiti huu ni kwamba utambuzi wa kifua kikuu kwa watoto ni mgumu kwa
sababu watoto hawana uwezo wa kutoa makohozi ili kuhakikisha ugonjwa wa kifua kikuu.
Kwasasa katika hospitali ya Bugando utambuzi wa kifua kikuu kwa watoto unafanywa kwa
kutumia chati za alama za kifua kikuu kwa watoto ambazo zinaangalia uwepo wa dalili na
alama za ugonjwa. Hii inaweza kuleta matatizo hasa katika maeneo ambayo yana
maambukizi mengi ya virusi vya ukimwi (VVU) kwasababu dalili nyingi za ugonjwa wa
kifua kikuu zinafanana na dalili za magonjwa yanayotokana na VVU na magonjwa mengine
ya mapafu. Hii inaweza kusababisha utambuzi usiosahihi wa kifua kikuu kwa watoto.
55
Kwahiyo, utafiti huu utatathimini chati za alama za kifua kikuu cha watoto katika kutambua
kifua kikuu cha mapafu kwa kulinganisha na kipimo cha makohozi cha hadubini na
kuotesha vijidudu vya kifua kikuu kutokana na makohozi yaliyo yaliyozalishwa kwa kuvuta
mvuke wa maji ya chumvi. Hii haitaathiri tiba utakayoipata ukiwa wodini kwa njia yotote
ile.
Taratibu za utafiti
Kabla ya kuingia kwenye utafiti huu tutaangalia iwapo mtoto wako anatimiza vigezo vya
kuingia kwenye utafiti.
Taratibu zitahusisha sisi kukuuliza juu ya hali ya maambikizi ya VVU ya mtoto wako,
kufanya kipimo cha TST (mojawapo ya kipimo cha kifua kikuu) na kupiga X-rei ya kifua.
Hivi ni vipimo muhimu kwa mgonjwa yoyote anaedhaniwa kuwa na ugonjwa wa kifua
kikuu.
Makohozi yatatolewa kwa kuvuta maji ya chumvi yaliyovukizwa ambayo yatamfanya
mototo wako kutoa na kukohoa makohozi. Kipimo cha PCR (GeneXpert) pia kitafanyika
ingawa matokeo ya kipimo hayatakuwa sehemu ya huu mradi.
Hatari za kushiriki katika utafiti
Kuvuta maji yenye chumvi yaliyovukizwa kwa ajili ya kutoa makohozi kwa nadira sana
kunaweza kusababisha kubanwa na pumuzi, ambako kunaweza weza kutibiwa na daktari
wa utafiti na siyo hatari.
Faida za kushiriki katika utafiti
Hakutakuwa na faida za moja moja kwako kutokana na huu utafiti. Hata hivyo, taarifa
zitakazopatikana kutoka kwenye huu utafiti zinaweza kuwa na manufaa kwa jamii
kwasababu zitaboresha utanbuzi wa kifua kikuu kwa watoto.
56
Usiri
Katika huu utafiti taarifa zote zitatunzwa kwa siri. Katika machapisho au maonyesho yoyote
hatutaweka taarifa ambazo zitawezesha kumtambua mtoto wako kama mshiriki.
Haki ya kujitoa
Kushiriki katika huu utafiti ni hiari. Una haki ya kujitoa kwenye utafiti huu wakati wowote
kama utaamua kufanya hivyo na hautotakiwa kutoa sababu. Uamuzi wako wa kushiriki au
kutoshiriki katika huu utafiti hakutoathiri mahusiano yako na watafiti. Kama utaamua
kushiriki, uko huru kujitoa wakati wowote bila kuathiri mahusiano hayo, au utambuzi wa
ugonjwa wako au tiba utakayopata.
Mawasiliano na Maswali
Utafiti huu unaongozwa na Dkt. Issa Sabi, CUHAS – Bugando. Unaweza kuuliza swali
lolote ulilonalo sasa. Kama utakuwa na maswali baadae, au kuumia kutokana na kushiriki
kwako katika utafiti tunakuhimiza kuwasiliana nae kupitia: Dkt. Issa Sabi, S.L.P 1464
Mwanza, Simu: +255 713 558722
Tamko la Ridhaa
Nimesoma maelezo hayo hapo juu. Nimeuliza maswali na nimepewa majibu. Ninaridhia
kushiriki katika huu utafiti.
JINA------------------------------------------------------- Namba ya Faili ---------------------Jina la mshiriki
JINA………………………………….Sahihi ……………………..Tarehe……………
Mzazi/mlezi
JINA………………………………….Sahihi ……………………..Tarehe……………
Shuhuda
JINA………………………………….Sahihi ……………………..Tarehe……………
Mtafiti
57
10.4
Sputum induction
Sputum induction can be used to obtain sputum from children or adults suspected with
pulmonary TB, who are unable to produce sputum. It is regarded as a routine procedure
with a low risk and few adverse events. Possible adverse events are coughing spells,
broncho-constriction and nosebleeds.
The procedure involves the insertion of a sterile suctioning tube through the nasopharynx
after nebulisation with a 5% NaCl solution. Sputum is then aspirated with a suctioning
pump.
Sputum induction can be done as an outpatient procedure and requires a fasting period of at
least 3 hours prior to procedure.
Sputum induction is an aerosol generating procedure, and must thus be performed in an
isolated room with adequate ventilation. If available, an ultraviolet light must be switched
on when the room is not in use.
Material
Nebulizer kit
Sterile paediatric oxygen mask (disposable)
Sterile suction tube (disposable)attached to mucus trap (size 7 to 8 French)
Sterile sputum container
Sterile gloves
Adult mask (N95)
58
Pulse oxymeter
5% NaCl solution
Salbutamol inhalate
Devices, instruments and aids
Nebulizer machine
Labels
Permanent marker
Transport box with cool packs
Disposable waste container
Oxygen cylinder
Procedure
Explain to the patient/parent/guardian the reason for sputum induction for sputum collection
and how the procedure is performed.
Explain to him/her that a fasting period of about 3 hours is required before the sputum
induction procedure
It is helpful to warn the patient that the inhalation might tickle a bit and can cause the urge
to cough, but that it is not going to hurt. The patient’s cooperation makes the procedure
easier.
Obtain an oral consent for the procedure
59
Record the following prior to procedure:
Time, pulse rate (PR), respiratory rate (RR), oxygen saturation (if oxygen saturation is
below 90% DO NOT do the procedure) and chest examination findings.
Procedure:
Prepare the nebulizer and fit the aspiration pump with a new sterile suctioning tube
Fill the medication tank with 5ml 5% saline solution (do not use normal saline)
Add 4 drops of Salbutamol to the medication tank
Reconnect the nebulizer cap to the medication tank
Connect the air tube, one end to the compressor unit (nebuliser machine) and the other end
to the bottom of the medication tank
Fit the mask to the top of the medication tank
Fit the mask to the patients face to ensure a close fit
Record PR, RR, oxygen saturation throughout the procedure according to the control sheet
for sputum induction
With the patient in the upright position, nebulise with 5 % hypertonic saline. Inhalation
period should last 10-15 minutes and should be individually adapted
A sputum collection container should be available at all times. If the patient feels to urge to
cough and expectorate spontaneously, even during inhalation, it should be done into the
sputum collection container
60
In case the patient did not cough/expectorate spontaneously during inhalation: after 10 - 15
minutes of inhalation, position the patient lying down in the left lateral position with a
wedge under the shoulders and percuss chest and back vigorously to loosen sputum
After percussion insert a sterile suctioning tube through the naso pharynx and turn the
suctioning pump on
Mucus will be trapped in the mucus trap
Remove the mucus trap, label the trap with the patient ID and sample number or transfer
sputum into labelled sterile sputum container
Transfer the specimen directly to the TB laboratory in a transport box with cool packs
If not enough sputum is generated after 15 minutes, inhaling can be repeated without the
addition of Salbutamol.
Discontinue if:
Continuous oxygen saturation of less than 90%
Marked increase in respiratory rate (more than 30% of baseline)
Moderate or severe lower airway obstruction
Severe increase in coughing
Patients with the following characteristics should not undergo sputum induction:
Inadequate fasting (less than 3 hours prior to procedure)
Severe respiratory distress (including rapid breathing, wheezing, hypoxia)
61
Oxygen saturation of less than 90%
Intubated patients
Patients with increased risk of bleeding, e.g. low platelet count
Reduced level of consciousness
History of significant asthma (diagnosed and treated by a clinician)
Quality assurance
Check if all containers are labelled, forms are filled and samples are complete before
handing everything over to the laboratory.
62
10.5
Diagnostic Scoring Systems
10.5.1 Keith Edward Score Chart
CLINICAL FEATURES
0
Duration
of
illness < 2
(weeks)
Nutrition (% weight for >80
age)
Family history of TB
None
1
2-4
2
3
>4
60 – 80
< 60
Reported
by family
Proven
sputum
+ve
Yes
Unexplained fever, night No
sweats, no response to
malaria treatment
TST positive
No
Lymph nodes: large, No
painless, soft sinus in
neck/axilla
Malnutrition
not No
improving after 4 weeks
CNS:
change
in No
temperament, fits with or
without abnormal csf
findings
Joint
swelling,
bone No
swelling, sinuses
Unexplained abdominal No
mass, ascities
Angle deformity of spine
No
Total score
A score of 7 or more indicates a high likelihood of TB.
63
4
Yes
Yes
Yes
Yes
Yes
Yes
Yes
SCORED
10.5.2 MASA System
CLINICAL FEATURES
YES
NO
Failure to gain weight
Cough > 2 weeks
Poor response to antibiotics
TST positive
Adult TB contact
Suggestive CXR
Threshold criteria for suspected TB: TST + CXR + any 1 other.
10.5.3 Fourie Scoring System
CLINICAL FEATURES
0 – 4 YRS 5 -14 YRS SCORE
Close contact with a known case of TB
2
2
TST positive
2
2
Persistent cough
2
1
Low wt/age (<90%) or progressive weight loss
3
3
Unexplained/prolonged fever
1
2
Total
A score of ≥ 5 is suggestive of TB
64
10.5.4 Brazilian MoH Scoring System
SCORE
CLINICAL MANIFESTATIONS
1. Fever or cough, lost energy, sputum, weight loss, night sweats
>2wks.
2. No symptoms or symptoms < 2wks
3. Respiratory infection improving with or without antibiotic therapy
for common bacteria
+15
0
-10
CXR
1. Enlarged hilum or miliary pattern
+15
2. Exudate or patch shadow (with or without cavitations) unaltered >
2wks or worst with antibiotic therapy for common bacteria.
+15
3. Exudate or patch shadow (with or without cavitations) < 2wks
+5
4. Normal
-5
CONTACT WITH TUBERCULOSIS ADULT
1. Close < 2yrs
+10
2. None or occasional
0
BCG vaccination and TST
1. BCG ≥ 2yrs or no BCG ( ≥10mm)
+15
2. BCG < 2yrs ( 15mm)
+15
3. BCG yes/no (5mm to 9mm)
+5
4. BCG yes/no ( ≤ 5mm)
0
NUTRITIONAL STATUS
1. Severe malnutrition (grade 3)
+5
2. Eutrophic or no severe malnutrition
0
TOTAL SCORE
Score interpretation: ≥ 40 PTB very likely; 30 -35 possible PTB; ≤25 PTB unlikely.
65
10.6
Tuberculin Skin Testing
A TST is the intradermal injection of a combination of mycobacterial antigens which elicit
an immune response (delayed-type hypersensitivity), represented by induration, which can
be measured in millimeters. The TST using the Mantoux method is the standard method of
identifying people infected with M. tuberculosis. Multiple puncture tests should not be used
to determine whether a person is infected, as these tests are unreliable (because the amount
of tuberculin injected intradermally cannot be precisely controlled). Details of how to
administer, read and interpret a TST are given below, using 5 tuberculin units (TU) of
tuberculin PPD-S. An alternative to 5 TU of tuberculin PPD-S is 2 TU of tuberculin PPD
RT23.
Administration
Locate and clean injection site 5–10 cm (2–4 inches) below elbow joint
9 Place forearm palm-side up on a firm, well-lit surface
9 Select an area free of barriers (e.g. scars, sores) to placing and reading
9 Clean the area with an alcohol swab
Prepare syringe
9 Check expiration date on vial and ensure vial contains tuberculin PPD-S (5 TU per
0.1ml)
9 Use a single-dose tuberculin syringe with a short (¼- to ½-inch) 27-gauge needle
with a short bevel
9 Fill the syringe with 0.1 ml tuberculin
Inject tuberculin
9 Insert the needle slowly, bevel up, at an angle of 5–15 °
9 Needle bevel should be visible just below skin surface.
66
Check injection site
After injection, a flat intradermal wheal of 8–10 mm diameter should appear. If not, repeat
the injection at a site at least 5 cm (2 inches) away from the original site.
Record information
Record all the information required by your institution for documentation (e.g. date and
time of test administration, injection site location, lot number of tuberculin).
Reading:
The results should be read between 48 and 72 hours after administration. A patient who
does not return within 72 hours will probably need to be rescheduled for another TST.
Inspect site
Visually inspect injection site under good light, and measure induration (thickening of the
skin), not erythema (reddening of the skin).
Palpate induration
9 Use fingertips to find margins of induration.
Mark induration
9 Use fingertips as a guide for marking widest edges of induration across the forearm
9 Measure diameter of induration using a clear flexible ruler
9 Place “0” of ruler line on the inside-left edge of the induration
9 Read ruler line on the inside-right edge of the induration (use lower measurement if
between two gradations on mm scale).
Record diameter of induration
9 Do not record as “positive” or “negative”.
9 Only record measurement in millimeters.
9 If no induration, record as 0 mm.
Interpretation:
67
Definitions of Positive Tuberculin Skin Test (TST) Results in Infants, Children, and
Adolescents
Induration 5 mm or greater
Children in close contact with known or suspected contagious people with tuberculosis
disease.
Children suspected to have tuberculosis disease
9 Findings on chest radiograph consistent with active or previous tuberculosis disease
9
Clinical evidence of tuberculosis disease
Children receiving immunosuppressive therapy or with immunosuppressive conditions,
including human immunodeficiency (HIV) infection
9 Induration 10 mm or greater:
Children at increased risk of disseminated tuberculosis disease:
9 Children younger than 4 years of age
9 Children with other medical conditions, including Hodgkin disease, lymphoma,
diabetes mellitus, chronic renal failure, or malnutrition
Children with likelihood of increased exposure to tuberculosis disease:
9 Children born in high-prevalence regions of the world
9 Children frequently exposed to adults who are HIV infected, homeless, users of
illicit drugs, residents of nursing homes, incarcerated or institutionalized, or migrant
farm workers
9 Children who travel to high-prevalence regions of the world Induration 15 mm or
greater:
9 Children 4 years of age or older without any risk factors
68
These definitions apply regardless of previous bacille Calmette-Guérin (BCG)
immunization; erythema alone at TST site does not indicate a positive test result. Tests
should be read at 48 to 72 hours after placement. Evidence by physical examination or
laboratory assessment that would include tuberculosis in the working differential diagnosis
(e.g., meningitis). Including immunosuppressive doses of corticosteroids
False positive reactions
Some persons may react to the TST even though they are not infected with M. tuberculosis.
The causes of these false-positive reactions may include, but are not limited to, the
following:
9 Infection with non-tuberculosis mycobacteria
9 Previous BCG vaccination
9 Incorrect method of TST administration
9 Incorrect interpretation of reaction
9 Incorrect bottle of antigen used
False negative reactions
Some persons may not react to the TST even though they are infected with M. tuberculosis.
The reasons for these false-negative reactions may include, but are not limited to, the
following:
9 Cutaneous anergy (anergy is the inability to react to skin tests because of a
weakened immune system).
9 Recent TB infection (within 8-10 weeks of exposure).
9 Very old TB infection (many years).
9 Very young age (less than 6 months old).
9 Recent live-virus vaccination (e.g., measles and smallpox).
69
9 Overwhelming TB disease, septicaemia
9 Some viral illnesses (e.g. measles and chicken pox).
9 Incorrect method of TST administration.
9 Incorrect interpretation of reaction.
9 Malnourishment, (advanced) HIV-infection or other reasons for immunosuppression (e.g. steroid therapy)
70
10.7
Study Budget
S/N Item
Unit cost (Tsh)
Quantity
Total cost (Tsh)
Proposal Development
1 Proposal writing and printing
500.00
60
30,000.00
Proposal photocopying (pages)
50.00 60pgx15cp
45,000.00
Questionnaire
photocopying(pages)
50.00
20,000.00
Stationery
400
Lump sum
100,000.00
2 Lab investigation and equipments
Suction machine
350,000.00
1
350,000.00
Nebulizer machine
150,000.00
1
150,000.00
3,500.00
200
700,000.00
500.00
150
75,000.00
Tuberculin skin test (10 doses
vial
35,000.00
10
350,000.00
LJ culture
10,000.00
200
2,000,000.00
5,000.00
200
1,000,000.00
Lump sum
500,000.00
Lump sum
800,000.00
TOTAL
6,120,000.00
Nebulizer masks
Mucus traps
Chest X ray
3
Data analysis, report writing
and printing
4 Contingency fund
71
10.8
Test for HIV Diagnosis
A: Children over 18 Months
72
B: Infant and Children below 18 months
73
10.9
Research Clearance Certificate
74