Nigeria – TB case finding among schoolchildren
A comparative study in Lagos assessed TB case-finding yield among schoolchildren using the WHO four-symptom screen and mobile chest X-ray with CAD. X-ray–based screening achieved a higher yield and lower testing burden, supporting its use for school-based active case finding.
School-based TB ACF
Active TB case finding was conducted among schoolchildren aged 6 to 15 years in Lagos.
Comparison of screening approaches
The WHO four-symptom screen was compared with mass mobile chest X-ray screening supported by CAD.
Identification of presumptive TB
Presumptive TB cases were identified through symptom screening or abnormal chest X-ray findings.
Confirmatory testing and clinical review
Sputum samples were tested using GeneXpert, with X-ray review and clinical assessment for negative or unavailable samples.
Over 6 months, a total of 13,384 school children were screened. In the W4SS group,
In the X-ray with CAD group,
- With W4SS, the Number Needed to Screen (NNS) was 158 and the Number Needed to Test (NNT) was 16.
- With CXR intervention, NNS was 152 and NNT was 9.
- Active case-finding based on CXR was preferable as the yield was better than the W4SS.
- Therefore, fewer cases would be missed and it would be worthwhile to invest more in the mobile CXR.
REFERENCE: A. Alege et al. (2022, November 8-11). Comparison of yield from symptomatic W4SS screening and mass mobile X-ray in schoolchildren in Lagos, Nigeria. The Union World Conference on Lung Health 2022.