THE INCIDENCE AND PREVALENCE OF HIV-INFECTION AMONG CHILDBEARING WOMEN LIVING IN EDINBURGH CITY, 1982-1995

Objective: To track the complete course of the HIV epidemic among wome n from the city of Edinburgh who delivered babies during 1982-1995. Me thods: The performance of the modified Serodia HIV test on dried blood spots from archived neonatal metabolic screening cards stored for up to 11 years was evaluated by testing 221 cards from neonates whose mot hers' HIV infection status was already known (100 HIV-positive, 121 HI V-negative). Unlinked anonymous HIV testing of cards from neonates bor n during 1982-1989 was then performed and the resulting prevalence dat a were combined with existing data from 1990-1995. Maximum and minimum limits of HIV incidence among women during the 36-month period prior to delivery were calculated using data held on a clinical database of HIV-infected pregnant women that had been generated under strict condi tions of confidentiality; these data included the date of the woman's first HIV-positive and, if available, last HIV-negative specimen. Resu lts: The evaluation revealed a sensitivity of 91%, not clearly related to storage time, and a specificity of 100%. HIV infection first enter ed Edinburgh's childbearing population during the early 1980s with pre valence peaking at 0.4% in 1986 and then decreasing to 0.1% in 1995; a similar incidence profile was seen during this period. Since 1986, th e first full year that HIV testing was available, 78% of all infection s were known during the pregnancy, 13% were identified retrospectively , and only 10% (10 cases) remain unaccounted for. For infected cases d uring 1984-1987, 78% were injecting drug users (IDU) and only 22% acqu ired their infection sexually; this distribution had reversed by 1992- 1995. Conclusion: HIV testing of neonatal metabolic screening cards st ored for up to 11 years can yield results of sufficient accuracy for e pidemiological purposes. There has been a substantial decline in the p revalence and incidence of HIV since the mid-1980s. Although new infec tions are still occurring, the numbers are small. The decline may larg ely be explained by the impact of preventive measures on the spread of HIV amongst IDU, and thus from IDU to their sexual partners. (C) 1998 Lippincott-Raven Publishers.