Background:  Data from 2 National Health and Nutrition Examinations Surveys (NHANES III 1988 to1994 and NHANES 1999 to 2002) were analyzed to examine trends in HIV seroprevalence in the United States household population.

Methods:  Serum from those aged 18 to 59 years in NHANES III and serum or urine from those aged 18 to 49 years in NHANES 1999 to 2002 were tested for HIV antibody and blood samples from HIV positive individuals and age matched controls examined in 1999 to 2002 were tested for CD4⁺ T lymphocytes. During 1999 to 2002 current medication use was obtained in the household interview and risk behaviors from a personal self interview in the examination center.

Results:  The age adjusted prevalence of HIV infection in NHANES III was 0.33% (95% CI, 0.22 to 0.52) as compared with a prevalence of 0.43% (95% CI 0.25 to 0.72) in 1999 to 2002. Prevalence was significantly higher among non-Hispanic blacks in the current survey going from 1.10% (95% CI 0.68 to 1.79) to 2.14% (95% CI 1.46 to 3.11). An analysis of risk factors in the current survey demonstrated that only intravenous drug use and herpes simplex-2 antibody were significant risks for infection among nono-Hispanic blacks. CD4⁺ T lymphocyte testing of the HIV positives and age matched controls, showed that 32% of infected individuals had CD4⁺ cell counts < 200 cell/mm³, but only 20% of these individuals reported ART use in the last 30 days; 19 infected individuals called for their test results, with 8 reporting that they were not previously aware of their HIV result. Of the 11 individuals who knew of their HIV status, 10 reported current HIV medication.

Conclusions:  HIV seroprevalence in the household population did not significantly change in the 10 years between the 2 surveys, but did significantly increase in the non-Hispanic black population. In the total population, 35% of HIV-infected individuals reported taking ART drugs compared with 18% in the non-Hispanic black population. Since 91% of those who knew their HIV status were being treated, awareness of HIV status continues to be an important component of HIV/AIDS prevention. Data from this representative sample of the U.S. household population demonstrates that racial and ethnic disparities in HIV infection are increasing on national level but since most individuals who knew about their infection were receiving treatment, an increased awareness and availability of HIV testing should help reduce these racial and ethnic disparities.  

Keywords: HIV seroprevalence; National survey; Trends in HIV prevalence