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Updated: May 10, 2026
A Tuberculosis Molecular Bacterial Load Assay (TB-MBLA)
Published on: April 30, 2020
Yield of contact tracing from pediatric tuberculosis index cases in Gaborone, Botswana
S Puryear1, G Seropola, A Ho-Foster
1Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA. spuryea1@jhmi.edu
Insights
Contact tracing using pediatric tuberculosis (TB) index cases identified new TB cases in Botswana. This approach shows similar yield to adult index cases, suggesting potential for improved evaluation of symptomatic contacts.
Area of Science:
- Public Health
- Infectious Diseases
- Pediatrics
Background:
- Contact tracing for pediatric tuberculosis (TB) is understudied in high TB and HIV prevalence areas.
- Investigating pediatric index cases for TB contact tracing is crucial for disease control.
Purpose of the Study:
- To assess the effectiveness of contact tracing in identifying new TB cases among household contacts of pediatric TB index cases in Botswana.
Main Methods:
- A study in Botswana included pediatric TB index cases (age ≤ 13 years) admitted between 2009-2011.
- Contact tracing involved home visits, symptom screening, and referral for TB evaluation.
- The primary outcome was the diagnosis of new TB cases in contacts.
Main Results:
- 163 pediatric index cases led to screening of 548 contacts.
- Twelve new TB cases were diagnosed (2.2% yield).
- Of diagnosed cases, 92% were smear-positive, and 70% were HIV-positive.
Conclusions:
- Contact tracing using pediatric index cases yields results comparable to the adult index case strategy.
- Enhancing the evaluation of symptomatic contacts could potentially increase the yield of TB case detection.
Setting:
Contact tracing using pediatric index cases has not been adequately investigated in high tuberculosis (TB) and human immunodeficiency virus (HIV) prevalence settings.
Objective:
To determine the yield of contact tracing in household contacts of pediatric TB index cases in Botswana.
Design:
Index cases included all pediatric (age ≤ 13 years) TB admissions from January 2009 to December 2011 to Botswana's largest referral hospital. A contact tracing team identified cases, conducted home visits, symptom-screened contacts and referred those with ≥ 1 TB symptoms. The primary outcome was newly diagnosed TB in a contact.
Results:
From 163 pediatric index cases, 548 contacts were screened (median 3 contacts/case, interquartile range [IQR] 2-4). Of these, 49 (9%) were referred for positive symptoms on screening and 27/49 (55%) were evaluated for active TB. Twelve new TB cases were diagnosed (12/548, 2.2%); the median age was 31 years (IQR 23-38); 11 (92%) were smear-positive. Ten (83%) had known HIV status: 7 (70%) were HIV-positive. To find one new TB case, the number needed to contact trace (index cases/new cases) was 13.6, and the number needed to screen (contacts/new cases) was 46.
Conclusion:
This yield of contact tracing using pediatric index cases is similar to the traditional adult index case approach. Improving the proportion of symptomatic contacts evaluated may increase yield.
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