Seroprevalence of herpes simplex virus type 1 among people living with HIV in Mbeya, Tanzania

BACKGROUND: Despite the significant decline in the prevalence of HIV in Tanzania, the prevalence rates in Mbeya, Iringa, and Njombe regions are higher than the national average and have remained stable for years. The current stable HIV prevalence may be driven by factors such as a high incidence of sexually transmitted infections (STIs) and high-risk behaviours. In sub-Saharan Africa, it has previously been observed that up to 50% of HIV cases were attributed to herpes simplex type 2 (HSV-2) among low-risk populations. Because the proportion of sexually transmitted HSV-1 is rising, it is essential to study the interaction between HSV-1 and HIV infections. METHODS: We conducted a study in Mbeya region using the archived blood sera of participants from the recently completed EU-funded EMINI project. A specially designed questionnaire was used to obtain the social and demographic characteristics of the study participants in the database. We tested archived participants’ sera for herpes simplex virus type 1 using Virotech HSV-1 (gG1) IgG ELISA (Enzygnost, Behring, Germany). Univariate and multivariate Poisson regression models were used to identify factors associated with HSV-1. RESULTS: A total of 640 adults were randomly recruited after stratification by HIV status (318 were HIV positive), age, and sex. The overall seroprevalence of HSV-1 in the study population was 92.1%. The extrapolated seroprevalence estimate of herpes simplex virus type 1 in the general population was 95.0% (96.0% in males versus 94.0% in females). Males and females were equally affected by HSV-1. HSV-1 was less prevalent in HIV-positive individuals than in HIV-negative individuals. CONCLUSION: People living with HIV were less likely to be HSV-1 seropositive. Further prospective studies are necessary to conclude a causal association.