Estimating the infectivity of HIV from partner studies

The main sources of data for estimating infectivity of the human immunodeficiency virus (HIV) come from studies of the susceptible partners of individuals known to be infected with HIV. Estimation of infectivity from these studies is complicated by limitations imposed by the sampling designs. This paper reviews three sampling schemes that have been used in partner studies and, for each, proposes methods for estimating various theoretic models for infectivity. The methods, as well as procedures for checking goodness-of-fit, are illustrated using data from a study by Peterman and colleagues.