Sex differences in systematic screening for tuberculosis among antiretroviral therapy naïve people with HIV in Kampala, Uganda.

Abstract

Background: Systematic tuberculosis (TB) screening is recommended for all people with HIV (PWH) because of its potential to improve TB outcomes through earlier diagnosis and treatment initiation. As such, systematic screening may be particularly important for men, who experience excess TB prevalence and mortality compared to women. We assessed sex differences among PWH undergoing systematic TB screening, including TB prevalence and severity, diagnostic accuracy of screening tools, and TB outcomes.

Methods: We enrolled and followed adults with HIV (CD4 ≤ 350 cells/µL) initiating antiretroviral therapy (ART) at two HIV/AIDS clinics in Uganda from July 2013 to December 2016. All participants underwent TB screening and sputum collection for TB testing (Xpert MTB/RIF [Xpert], culture). We evaluated diagnostic accuracy of four WHO-recommended TB screening strategies (symptom screen; C-reactive protiein [CRP]; symptom screen followed by CRP, if symptomatic [symptoms + CRP]; Xpert) for culture-positive TB and compared TB prevalence, days-to-treatment initiation, and 3-month mortality by sex.

Results: Of 1,549 participants, 727 (46.9%) were male and 236 (15.2%) had culture-positive TB. Compared to females, males had lower pre-ART CD4 counts (median 139 vs. 183 cells/µL, p < 0.001), higher TB prevalence (20.5% vs. 10.6%, p < 0.001), and higher mycobacterial load as measured by Xpert semi-quantitative grade (p = 0.03). Sensitivity was high (≥ 89.8%) for all screening strategies except Xpert (Xpert sensitivity 57.2%) and did not differ by sex. Specificity varied widely from 13.9% for symptom screen to 99.2% for Xpert, and was 5-15% lower for males than females for symptom screen, CRP, and symptoms + CRP. Among PWH with culture-positive TB, median days-to-treatment initiation (2 vs. 4, p = 0.13) and 3-month mortality (9.4% vs. 9.2%, p = 0.96) were similar for males and females.

Conclusions: Although ART-naïve males undergoing systematic screening had more advanced HIV and TB than females, days-to-TB treatment initiation and early TB mortality were similar, suggesting that systematic TB screening has the potential to reduce sex-based disparities in TB outcomes.