A hospital-based surveillance of HIV infection was implemented in the Bordeaux Regional University Hospital (France). This reporting system, initiated by the Groupe d'Epidemiologie Clinique du SIDA en Aquitaine, identified and followed-up 89 adult patients with transfusion-associated HIV-1 infection (7.2% of all reported cases). Contamination occurred between August 1981 and June 1985 and diagnosis was made between 1985 and 1989. By 30 June 1990, 43 patients (48.3%) had full-blown AIDS, and 28 of them had died. The mean follow-up period was 66 months (s.d. 16 months). The mean incubation period, i.e. The time interval between the contaminating transfusion and the development of full-blown AIDS, was 62 months [median 73 months; 95% confidence interval (CI) 66-82 months]. Five years after contamination, the cumulative probability of reaching the AIDS stage was 34.2% (95% CI 20.3-49.3%), and the probability of survival was 81.7% (95% CI 72.5-90.0%). From this surveillance system we estimate that in south-western France at the end of 1989 the cumulative incidence of transfusion-associated HIV-1 infection was at least 126 cases (45.6 per million inhabitants). Although we anticipate an increase in transfusion-associated AIDS cases over the next 5 years, there have been no reports of contamination after 1 August 1985, when systematic screening of HIV antibodies was implemented in French blood banks. This confirms the efficacy of screening in countries like France where the risk of contamination through blood products is now minimal.