High incidence of tuberculosis in young children living with HIV in the Western Cape, South Africa

Background: Data on tuberculosis (TB) incidence and risk factors among children living with HIV (CLHIV) in the universal ART era are limited.

Methods: We analysed routinely-collected data on TB diagnoses for CLHIV age ≤5 years, born 2018-2022, in the Westen Cape, South Africa. We examined factors associated with TB diagnosis, with death and loss to follow-up as competing events.

Results: Among 2,219 CLHIV, 30% were diagnosed with HIV at birth. Median follow-up from birth was 38 months (IQR 24-50); 90% started antiretroviral therapy (ART). TB was diagnosed in 28% of CLHIV (n=626/2219); 62% were first diagnosed before/within 3 months of ART start ('TB before ART') and 38% >3 months after ART start ('TB after ART'). Of those with 'TB before ART' (n=390), median age at HIV diagnosis was 13 months (IQR:6-22); median time between HIV and TB diagnoses was 5 days (IQR:0-31). 'TB before ART' was associated with older age at HIV diagnosis and advanced/severe immunodeficiency. Of those with 'TB after ART' (n=258), median age at HIV diagnosis was 2 months (IQR 0-8) and median time from ART start to TB diagnosis was 12 months (IQR:7-21). 'TB after ART' was associated with increased viral load and advanced/severe immunosuppression (time-updated). Overall, 5% (n=112/2219) of CLHIV died, 36% of whom were diagnosed with TB (median time from TB diagnosis to death: 58 days; IQR:17-191).

Conclusions: Young CLHIV in this setting have high TB-associated morbidity and mortality. Efforts to improve early HIV and TB diagnosis, viral suppression and TB preventive therapy are needed.