Prevalence of latent tuberculosis infection in HIV-1-infected children on antiretroviral therapy in Jos, Nigeria

Background: There are few studies investigating the prevalence of latent tuberculosis infection (LTBI) in HIV-1-infected children on antiretroviral therapy (ART), but no data from Nigeria. This study determined the prevalence of LTBI in HIV-1-infected children on ART in our clinic. Knowing the prevalence and thus the burden of LTBI could help improve HIV care by enabling targeted isoniazid (INH) prophylaxis.

Method: This observational study was carried out from September 2016 to August 2017 at the pediatric HIV clinic of the Jos University Teaching Hospital among HIV-1-infected children on ART, aged 6 months-15 years. LTBI was diagnosed using an interferon-gamma release assay, the ELISpot test, T-SPOT®.TB assay (Oxford Immunotec, Abingdon, UK) on freshly collected whole blood samples within 2 h. Children with a positive test were treated with INH after first excluding TB by chest X-ray and clinical evaluation.

Results: Of the 90 children studied, 4 (4.4%) had LTBI diagnosed by ELISpot. Their median interquartile range (IQR) age was 10.4 years (7.9-12.5), the majority were male (54.4%) and most of them had originally received Bacille Calmette-Guérin (83/89, 93.3%). They had a median CD4 count of 694 cells/μL (472-1045). The median (IQR) CD4 count was higher in LTBI compared to non-LTBI children: 1286 cells/μL (953-1375) versus 683 cells/μL (465-1040), (P = 0.044).

Conclusion: Although this study showed a very low prevalence of LTBI in our setting, it was still beneficial to the few children on ART identified with LTBI as it enabled treatment with INH. A larger study will be required to ascertain the actual burden of LTBI in such children in our setting.