Type of partnership and heterosexual spread of HIV infection in rural Uganda: results from simulation modelling

Abstract

The objective was to estimate the likely percentage of HIV infections that may be attributable to one-off partnerships (such as those between female sex workers and their clients) and longer-term partnerships in rural Uganda. This was addressed by the application of a microsimulation model (SimulAIDS) of the transmission dynamics of HIV infection, drawing on data from a population cohort of 10,000 in rural Uganda. For a scenario reproducing documented characteristics of the study population in 1990, when adult HIV prevalence was 9%, and during subsequent follow up (1990-1994), when adult HIV incidence was 8 per 1000 person-years, the percentage of HIV infections in men (women) attributed to one-off partnerships decreased from 96% (26%) during 1980 to 67% (8%) in 1989 and 22% (5%) in 1994. Reducing HIV transmission between one-off partners early in an HIV epidemic may substantially limit the potential for the spread of HIV infection. At a later phase, prevention must also focus on control of transmission between longer-term HIV-discordant partners.

PIP: This paper presents results of a study using a simulation model in estimating the likely percentage of HIV infections that may be attributable to one-off partnerships (e.g., female sex workers and their clients) and longer-term partnerships among the rural population of Uganda. The study adopted SimulAIDS, an age-structured microsimulation model of the HIV infection dynamics along with ulcerative and non-ulcerative sexually transmitted diseases. Data obtained from the 10,000 cohort population reflected a decline in the incidence of HIV in adults between 1990 and 1994, a result which could be attributed to one-off sexual partnerships in 1980, 1984, 1989, 1994, and 1999. The study supports that minimizing transmission of HIV from short-term sexual partnerships during early stage of the disease could have a strong impact on the reduction in the spread of HIV infection.