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Asymptomatic Tuberculosis in Children With Household Exposure to Mycobacterium tuberculosis
Humphrey Mulenga1, Justin Shenje1, Simon C Mendelsohn1
1South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa.
Insights
Asymptomatic tuberculosis (TB) is common in young children exposed to TB. Active investigation for childhood TB is crucial in all exposed contacts, regardless of symptoms, to ensure timely diagnosis and treatment.
Area of Science:
- Pediatric infectious diseases
- Public health
- Tuberculosis research
Background:
- Asymptomatic tuberculosis (TB) is frequently observed in adults but understudied in children due to diagnostic limitations.
- Current diagnostic approaches for childhood TB often exclude asymptomatic individuals, creating a knowledge gap.
Purpose of the Study:
- To investigate the prevalence and characteristics of asymptomatic tuberculosis (TB) in young children with household exposure to infectious adults.
- To evaluate the utility of diagnostic criteria in identifying TB in asymptomatic children.
Main Methods:
- A study in South Africa enrolled 430 children (2-60 months) with household TB exposure, excluding those with HIV.
- Methods included symptom screening, chest radiography (CXR), and induced sputum analysis.
- Confirmed and Unconfirmed TB were defined using a consensus case definition, with asymptomatic TB defined as meeting criteria without reported symptoms.
Main Results:
- 154 (35.8%) children met TB diagnostic criteria; 55 (35.7%) of these TB cases were asymptomatic.
- Asymptomatic cases showed a higher rate of chest radiography compatibility with TB (73.2%) compared to symptomatic cases.
- TB treatment was initiated in 80% of asymptomatic TB cases versus 34.3% of symptomatic cases.
Conclusions:
- Asymptomatic tuberculosis, meeting consensus case definitions, is prevalent in TB-exposed children.
- Active investigation for TB in all child household contacts is recommended, irrespective of symptom presence, to guide therapy decisions.
Background:
Asymptomatic tuberculosis (TB) is common in adult community prevalence surveys. Evidence to inform our understanding of asymptomatic TB in children is lacking, because diagnostic algorithms typically include only symptomatic children.
Methods:
Children aged 2-60 months, without human immunodeficiency virus (HIV), with household exposure to an adult TB patient in the last year, were enrolled in South Africa. Symptom screening, chest radiography (CXR) and induced sputum were performed. Confirmed TB (requiring positive Xpert Ultra and/or MGIT culture) and unconfirmed TB (requiring 2 of TB exposure, compatible symptoms, or compatible CXR) were defined by application of a consensus case definition for classification of childhood TB. Asymptomatic TB was defined as Confirmed or Unconfirmed TB without reported symptoms.
Results:
In brief, 430 TB-exposed children, median age 25.9 (interquartile range [IQR] 13.5-40.0) months, were enrolled. And 154 (35.8%) children met TB diagnostic criteria, including 21 (4.9%) Confirmed and 133 (30.9%) Unconfirmed cases. Fifty-five (35.7%) of all TB cases were asymptomatic, including 17/21 (81.0%) Confirmed and 38/133 (28.6%) Unconfirmed cases. CXR was compatible with TB in 30/41 (73.2%) asymptomatic versus 15/47 (31.9%) symptomatic cases who underwent CXR (P < .001). TB treatment was started in 44/55 (80%) asymptomatic versus 34/99 (34.3%) symptomatic cases (P < .001). Factors associated with asymptomatic compared to symptomatic TB included microbiological confirmation (adjusted odds ratio [aOR] = 3.73; 95% confidence interval [CI]: 1.08-12.88).
Conclusions:
Asymptomatic TB that meets the consensus case definitions for both Confirmed and Unconfirmed disease is common in TB-exposed children. All child household contacts should be actively investigated for TB, regardless of symptoms, before a decision is made on curative or preventive therapy.
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