The differential impact of hiv and art on gender-specific tuberculosis rates.

OBJECTIVE: To assess the impact of the HIV epidemic and the roll-out of antiretroviral therapy (ART, from 2004) on the gender-specific TB burden in Cape Town, we investigated temporal changes in TB notification rates, the HIV-associated relative risk of TB and the population attributable risk fraction (PAF) of HIV by gender.

METHODS: Annual TB notifications, mid-year population and HIV prevalence estimates were used to calculate rates per 100,000 population stratified by gender and HIV. Annual rate ratios (RR) of TB associated with HIV and PAF were calculated by gender.

RESULTS: Pre-HIV TB notification rates were lower among women than men (146/100,000 versus 247/100,000). With the onset of the HIV epidemic rates increased 5.3-fold in women (to 778/100,000) and 3.7-fold in men (to 917/100,000) to a peak in 2008, after which they declined by 25% in women (to 634/100,000) and 18% in men (to 755/100,000) by 2014. The HIV-associated RR of TB was 25% higher in women than men in 2006 (25 versus 20), but decreased to the same level in 2014. HIV PAF declined between 2008 and 2014 from 56% to 50% and from 40% to 38% in women and men, respectively.

CONCLUSIONS: The HIV epidemic led to greater relative increases in TB rates among women than men. The increased HIV-associated TB risk in women could be compatible with removal of the biological protection of female gender by HIV infection. The decline in RR and PAF in HIV-positive women could be explained by increasing ART usage reversing female gender-related susceptibility. This article is protected by copyright. All rights reserved.