HIV prevalence among foreign- and US-born clients of public STD clinics.

OBJECTIVES: We examined differences in HIV seroprevalence and the likely timing of HIV infection by birth region. METHODS: We analyzed unlinked HIV antibody data on 61 120 specimens from 7 public health centers in Los Angeles County from 1993 to 1999. RESULTS: Most (87%) immigrant clients were Central American/Mexican-born. HIV prevalence was similar for US- and foreign-born clients (1.8% [95% confidence interval (CI) = 1.7%, 1.9%] and 1.6% [95% CI = 1.5%, 1.8%], respectively). Seroprevalence was high among sub-Saharan African females and low among Asian/Pacific Islander males and females. For HIV-positive immigrants, the average age at and time since immigration were 20.6 years and 12.3 years, respectively. CONCLUSIONS: The relatively young age at arrival and long time since arrival for HIV-positive foreign-born clients suggest that most were infected after immigration.