Joint modeling of correlated binary outcomes: HIV-1 and HSV-2 co-infection

Abstract

Herpes Simplex Virus Type 2 (HSV-2) facilitates the sexual acquisition and transmission of HIV-1 infection and is highly prevalent in most regions experiencing severe HIV epidemics. In sub-Saharan Africa, where HIV infection is a public health burden, the prevalence of HSV-2 is substantially high. The high prevalence of HSV-2 and the association between HSV-2 infection and HIV-1 acquisition could play a significant role in the spread of HIV-1 in the region. The objective of our study was to identify risk factors for HSV-2 and HIV-1 infections among men in sub-Saharan Africa. We used a joint response model that accommodates the interdependence between the two infections in assessing their risk factors. Simulation studies show superiority of the joint response model compared to the traditional models which ignore the dependence between the two infections. We found higher odds of having HSV-2/HIV-1 among older men, in men who had multiple sexual partners, abused alcohol, or reported symptoms of sexually transmitted infections. These findings suggest that interventions that identify and control the risk factors of the two infections should be part of HIV-1 prevention programs in sub-Saharan Africa where antiretroviral therapy is not readily available.