Decreasing seroprevalence of human immunodeficiency virus type 1 in a regional blood donor population.

Blood banks have intensified their efforts to discourage donations from individuals at risk for the human immunodeficiency virus (HIV-1). Since the onset of HIV-1 donor screening in April 1985, a marked reduction in seroprevalence has been seen at the authors' institutions: from 51 cases per 100,000 donors in 1985 to 13 per 100,000 in the first 6 months of 1988. Data from 3.5 years have been analyzed for temporal trends in the association of HIV-1 seroprevalence with donation site (urban vs. non-urban) and donor gender. The association of HIV-1 seropositivity with an urban donation site decreased through 1987 as the urban-to-nonurban donation odds ratio declined from 6.48 in 1985 to 2.54 in 1987. Despite this decrease, both men and women who donated in urban areas had a significantly higher seroprevalence than those in nonurban areas. Male donors had a higher overall HIV-1 seroprevalence than female donors. However, the male-to-female odds ratio declined from 2.94 in 1985 to 1.96 in 1988, and male gender was no longer significantly associated with HIV-1 seropositivity. This change in the donor profile appears to reflect declining numbers of seropositive men who acknowledge risk factors and greater numbers of women with no identified risks for HIV-1. This study documents a dramatic decrease in HIV-1-seropositive donors and suggests that the deferral of high-risk individuals has become increasingly successful.