U.S.-born attendees at sexually transmitted disease (STD) clinics are as likely as foreign-born attendees to have HIV, and most HIV-positive attendees who were born abroad were probably infected after entering the United States.1 At selected STD clinics in Los Angeles County in 1993-1999, similar proportions of U.S.- and foreign-born clients--1.8% and 1.6%, respectively--tested positive for HIV. HIV was most prevalent among clients born in North Africa and the Middle East (3.3%) and least prevalent among those from East Asia and the Pacific Islands (0.5%). Considering the average age of foreign-born clients, their age at immigration and the number of years they had lived in the United States, most of these attendees had likely contracted the virus after immigration.
Between January 1993 and December 1999, researchers investigated whether birthplace was associated with HIV prevalence among attendees at STD clinics at seven public health centers in Los Angeles County. They tested clients anonymously for the presence of HIV antibodies and recorded clients' birthplace, race and ethnicity, current age and HIV risk behavior. In addition, they estimated age at immigration and the number of years since immigration for clients born outside the United States (defined as the 50 states). Complete information was available for 61,120 clients.
The proportion of clinic attendees born in the United States was higher than that of attendees born elsewhere (62% vs. 38%). The vast majority of immigrants were born in Central America or Mexico (87%) and were Hispanic (87%); in contrast, most U.S-born clients were non-Hispanic and black (75%). The mean ages of U.S.- and foreign-born clients were similar (29 and 30 years, respectively), as were the proportions who were female (38% and 42%) and the proportions who tested positive for HIV (1.8% and 1.6%). HIV was most prevalent among clients born in North Africa and the Middle East (3.3%) and among those born in the Caribbean and the West Indies (2.9%); it was least prevalent among clients from East Asia and the Pacific Islands (0.5%) and among those from South and Southeast Asia (0.7%). Attendees from Central America and Mexico, Europe and the former Soviet Union, Sub-Saharan Africa and South America had intermediate HIV prevalence levels (1.6-2.2%). Of the 1% of immigrants who were born in U.S. territories, 2.4% tested positive for HIV.
Overall, HIV prevalence was higher among males than among females, both for attendees born in the United States (2.6% vs. 0.6%) and for those born abroad (2.5% vs. 0.4%). The general trend was reversed only among immigrants from Sub-Saharan Africa: In this group, 5.7% of women and 0.9% of men had HIV. Women from this region also had the highest HIV prevalence of all groups studied.
Multivariate logistic regression analysis that controlled for current age and risk behavior (i.e., history of male homosexual activity, of exclusive heterosexual activity and of drug injection) revealed that the odds of testing positive for HIV were significantly elevated for women from Sub-Saharan Africa (odds ratio, 8.6) and significantly reduced for women from Central America and Mexico (0.5), compared with the odds for U.S.-born women. Men who were born in South and Southeast Asia were less likely than U.S.-born men to test positive for HIV (0.3).
Foreign-born clients who were HIV-positive were older than those who were HIV-negative (mean age, 33 vs. 30); they also were older at immigration (21 vs. 19) and had lived in the United States for longer (12 vs. 10 years). Acknowledging that most people with AIDS receive their diagnosis in their 30s and that the median time between untreated HIV infection and AIDS diagnosis is 10-12 years, the researchers conclude that most HIV-positive clients from abroad had likely been infected after immigration, perhaps because of an elevated HIV risk in the United States. They point out, however, that immigrants often visit their country of birth, where they might acquire HIV. In contrast, clients born in Sub-Saharan Africa who tested positive for HIV had lived in the United States for only about three years, and they had immigrated, on average, at age 24. According to the analysts, the majority of these clients had therefore probably been infected before moving to the United States.
Noting that their findings are relevant to urban areas of the country that have sizable and expanding foreign-born populations, the researchers conclude that although foreign-born clients of public STD clinics are as likely as U.S.-born clients to have HIV, they may encounter multiple disadvantages in seeking treatment, such as poverty, lack of medical insurance and difficulty understanding English. Furthermore, "elevated HIV prevalences in some foreign-born subgroups suggest that specific immigrant populations warrant special attention." In particular, the researchers note, HIV programs need to target African, Caribbean and Middle Eastern immigrants because of their high HIV prevalence, as well as Central American and Mexican immigrants because of their large and increasing numbers in the United States. The authors also call for "research to identify factors that elevate some immigrants' HIV risk and to evaluate whether HIV services meet [their] needs."--T. Lane
1. Harawa NT et al., HIV prevalence among foreign- and US-born clients of public STD clinics, American Journal of Public Health, 2002, 92(12):1958-1963.