Relative HIV Resistance in Kenyan Sex Workers is Not Due to an Altered Prevalence or Mucosal Immune Impact of Herpes Simplex Virus Type 2 Infection

Chronic infection by herpes simplex virus type 2 (HSV-2) increases HIV susceptibility, perhaps due to HSV-2-associated increases in activated mucosal immune cells. A small number of Kenyan female sex workers (FSWs) exhibit relative HIV resistance. We examined whether relative HIV resistance was related to differences in the prevalence or mucosal immune impact of HSV-2. Participants were recruited from an open cohort of HIV-uninfected FSWs in Nairobi, Kenya. Women who had been practicing sex work in the cohort for 3 years without acquiring HIV were defined as relatively HIV resistant. HSV-2 diagnostics were performed, and cervical immune cell subsets were examined by flow cytometry in a subset of participants. The study population comprised 139 HIV-uninfected FSWs. HSV-2 seroprevalence was actually higher in FSWs meeting criteria for relative HIV resistance than in non-resistant FSWs (75/80, 94% vs 46/59, 78%; LR = 7.5; P = 0.006), likely due to the increased age and longer duration of sex work in the resistant subgroup. Late HIV acquisition was not associated with recent HSV-2 infection, and HSV-2 associated increases in HIV-susceptible cervical immune cell populations were similar in both groups. Relative HIV resistance in Kenyan FSWs was not due to a reduced prevalence or mucosal immune impact of HSV-2 infection.