148 AJTCCM VOL. 30 NO. 4 2024
EDITORIAL
Tuberculosis (TB) continues to be a public health problem, especially
in children and in low- and middle-income countries (LMICs).[1,2] While
signicant progress has been made in the diagnosis and treatment
of adult TB, paediatric TB diagnosis lags behind owing to unique
challenges in young children.[3,4] ese include: (i) obtaining reliable
respiratory samples from young children; (ii) nonspecic symptoms
of TB in this population; and (iii) the paucibacillary nature of
the disease, making diagnosis and treatment challenging in this
population.[5-7] Unlike adults, who can produce sputum on demand for
testing, young children do not expectorate sputum spontaneously.[3,4,8]
is problem is compounded by the fact that even when samples are
obtained, they are oen of poor quality, low in volume, or have a bacillary
concentration below the detection threshold of conventional tests.[8,9] As
a result, paediatric TB is oen underdiagnosed or misdiagnosed, leading
to delays in treatment and in some cases to preventable deaths.[9,10]
Clinicians in TB-endemic LMICs may have to rely on clinical suspicion
and radiological ndings to diagnose TB. While helpful, these do not
provide microbiological conrmation to tailor treatment, especially in
cases of drug-resistant TB.[6,11]
Sputum induction involves nebulising the patient with hypertonic
saline, which helps to loosen the secretions in the lungs and enables
even very young children to produce a sputum sample for testing.[12] e
study by Owusu et al.[13] in this issue of AJTCCM is a step towards
improving TB diagnostics in a low-resource setting in Ghana. In
this 6-month prospective cross-sectional study at Komfo Anokye
Teaching Hospital in Kumasi, children aged 3 months - 14 years
suspected of having pulmonary TB were enrolled. Induced sputum
(IS) samples were collected within 48 hours of admission from 144
children. e authors carefully assessed the children and excluded
those who presented with severe hypoxia (<92% on supplemental
oxygen), severe bronchospasm, seizures or inability to protect their
airways, and those who tested positive for COVID-19. Samples were
analysed using the Xpert MTB/RIF Ultra test to conrm the presence
of Mycobacterium tuberculosis. Safety was monitored by recording
vital signs (temperature, respiratory rate, oxygen saturation) before
and aer the procedure and noting any adverse events (epistaxis).
In this study, IS had a microbiological conrmation rate of 68%
using the Xpert Ultra test. In comparison, the routinely used gastric
lavage is more invasive, requires an overnight fast and three specimens,
and has lower sensitivity. In a previous study by Zar et al.,[14] IS had a
higher yield than gastric lavage, 87% of children testing positive with
IS compared with 65% with gastric lavage (p=0.018). One IS sample
demonstrated sensitivities equivalent to three gastric lavages. e
microbiological yield from IS was similar in both HIV-infected and
uninfected children aged >1 month (p=0.17). is nding suggests
that IS is eective for use in all children aged >1 month, regardless
of their HIV status.[14] Sputum induction is also a safe procedure.
In Owusu et al.’s [13] study, adverse events were minimal; 2.1% of the
children had minor epistaxis that resolved without complications.
Similar to the study by Zar et al.,[14] side-eects such as coughing,
epistaxis, vomiting and wheezing were minor and well tolerated.
Other studies from South Africa, e Gambia and ailand reported
similar safety outcomes, with no signicant changes in vital signs
before and aer the procedure.[15-18] Given its safety prole and high
yield, sputum induction can be done even in resource-poor settings
where advanced medical interventions are not available.
e practical benets of sputum induction are also important,
as induction can be done in an outpatient setting, making it more
accessible to healthcare providers in LMICs. This advantage is
particularly important in rural or under-served areas where healthcare
resources are limited and access to tertiary care facilities is oen
constrained. Sputum induction in primary care settings can increase
the reach of TB diagnostic services and enable earlier detection
and treatment of paediatric TB. By increasing the availability of
good-quality diagnostic samples, sputum induction can also reduce
overdiagnosis and underdiagnosis of TB in children, and therefore
enable more accurate treatment and better health outcomes.
Sputum induction in LMICs is not without its challenges. While
the procedure itself is simple, healthcare workers need to be trained
to do it safely and well. In many LMICs, health systems are already
thinly stretched with limited numbers of trained sta and resources.
To scale up sputum induction, investment will be needed in training
programmes, equipment and infrastructure, especially in rural areas
where healthcare workers may not have the specialised training to
carry out this diagnostic procedure.
Another challenge is over-reliance on sputum induction at the
expense of other diagnostic tools. Sputum induction has proved to be
eective for pulmonary TB, but it is not a magic bullet.[14] In cases of
extrapulmonary TB, sputum induction may not be the best diagnostic
tool. Health systems therefore need to have a balanced approach,
integrating sputum induction into broader diagnostic algorithms that
include clinical evaluation, radiological imaging and other laboratory
tests. Such an approach will mean that all forms of TB, including drug-
resistant and extrapulmonary TB, will be diagnosed accurately and
treated appropriately.
Besides sputum induction, research is proceeding on alternative
diagnostic methods to improve TB detection in children. One area
of research is stool samples for TB diagnosis. Stool-based diagnostics
have the advantage of being non-invasive, and stool samples are easy
to collect, especially from very young children who cannot produce
sputum.[19,20] Recent studies have shown that testing of stool samples
for TB using GeneXpert MTB/RIF can be as sensitive as testing sputum
samples.[20] Stool-based diagnostics are still in the early stages, and
more research is needed to standardise the processing and results. e
potential of stool-based diagnostics to complement or even replace
sputum induction in some cases is an exciting development for the
future of paediatric TB diagnosis.
While the world invests in new diagnostics, we need to remember
that merely investing in new technologies is not enough for getting
these tools out there and used in LMICs. Policymakers, healthcare
A critical perspective on paediatric pulmonary tuberculosis and
diagnostic advancements
AJTCCM VOL. 30 NO. 4 2024 149
EDITORIAL
providers and researchers need to unite to find solutions for the
practical challenges of implementers who are looking to adapt new
diagnostics such as sputum induction. ese eorts include not only
training and providing materials for healthcare workers to perform
these procedures, but also working with local communities to create
a sense of trust and understanding about incoming diagnostics.
Caregiver and patient acceptance of procedures such as sputum
induction can be low, even if these procedures are safe.
Using IS for TB diagnosis is an advance that can potentially bridge
the diagnostic gap in LMICs and play a major role in global health
initiatives, especially United Nations Sustainable Development
Goal (SDG) 3: Good health and well-being. SDG 3 aims to end the
epidemics of TB, HIV/AIDS, malaria and neglected tropical diseases
by 2030. Reducing child mortality from TB is a key component of
achieving this target. Implementing better diagnostic tools such
as sputum induction can lead to earlier and more accurate TB
detection, better treatment outcomes, less disease transmission, and
lower TB mortality in children. By ensuring that these diagnostic
advancements are incorporated into national health programmes in
LMICs, countries can make big strides towards meeting their global
TB elimination targets.
K Mochankana, MMed (Paed)
Department of Paediatrics and Child Health, School of Clinical Medicine,
College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
kmochankana@yahoo.com
R Masekela, MMed (Paed), PhD
Department of Paediatrics and Child Health, School of Clinical Medicine,
College of Health Sciences, University of KwaZulu-Natal, Durban, South
Africa; Africa Health Research Institute, Durban, South Africa
masekelar@ukzn.ac.za
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