[The survey of HIV infection among clients of foreign female prostitutes in Tokyo Metropolitan].

Objectives: It is important to elucidate the risks to foreign female prostitutes of HIV infection from their clients. We determined the prevalence of HIV among clients of foreign female prostitutes using anonymous testing of condom semen samples.

Methods: A total of 250 client condom semen samples were collected with client age and nationality by 15 Latin American and 37 Thai female prostitutes in Tokyo from March to May 1995. We screened by ELISA (GENELAVIA MIXT, Pasteur Sanofi Diagnostics) for antibody to HIV 1 and 2, and then confirmed by Western Blot (LAV Blot 1, LAV Blot 2, Sanofi Diagnostics Pasteur) and distinguished by Immuno Blot PEPTI-LAV 1, 2, (Sanofi Diagnostics Pasteur).

Results: The nationality of customers was reported as Japanese (74.8%), Iranian (7.6%), Pakistan (5.6%), Indian (2.8%), Taiwanese (2.0%), and Chinese (1.2%) with other nationalities less than 1.0%. Estimated age categories of the clients were < 20 (1.2%), 20-29 (41.2%), 30-39 (36.4%), 40-49 (12.4%), > or = 50 (6.4%) and undetermined (2.4%). Of the 250 samples collected, only 219 were sufficient for testing. Two samples (0.90%, 95% CI = 0.4-2.2%) were HIV 1 positive, both from Japanese clients (1.2% of Japanese clients, 95% CI = 0.5-2.9%). These data suggested that the prevalence of HIV in clients of female prostitutes was relatively high, and can be considered a risk group in Japan. The sentinel surveillance by anonymous of client condom semen samples is a very useful method to quantify HIV prevalence in this risk group.