HIV Prevalence Has Remained Low and Stable since the Early 1990s in U.S. Household-based Population

		SUMMARY: U.S. HIV prevalence rates have remained remarkably low -- at 0.5% -- and stable over time in the national household-based population assessed by the National Health and Nutrition Examination Survey (NHANES), according to a report in the January 2010 Journal of Acquired Immune Deficiency Syndromes. Household surveys do not include some populations at elevated risk for HIV, including homeless people and prisoners, which helps explain variance between these findings and other broader national prevalence estimates.

By Liz Highleyman

Geraldine McQuillan and colleagues from the Centers for Disease Control and Prevention (CDC) looked at trends in HIV prevalence, or total number of infections both new and old, in surveyed household populations over time.

The National Health and Nutrition Examination Survey, conducted repeatedly since the 1960s, is designed to assess the health and nutritional status of adults and children in the U.S. using both interviews and physical examinations.

The present analysis looked at data collected between 1999 and 2006 (broken down into 2 periods, NHANES 1999-2002 and NHANES 2003-2006); data were also compared with findings from NHANES III (1988-1994).

During 1999-2006, a total of 11,928 participants aged 18-49 years received HIV antibody tests as part of the survey. Prevalence estimates were weighted to account for over-sampling and non-response.

Results

	67 people out of 11,928 survey participants had reactive (positive) HIV antibody tests during 1999-2006, for an overall seroprevalence rate of 0.5% (95% confidence interval 0.3-0.6).
	Among people age 18-39 (the only age group directly comparable across surveys), HIV prevalence remained constant over the 3 NHANES periods.
	During the entire 1999-2006 period, non-Hispanic black participants had significantly higher HIV prevalence, at 2.0%, than all other racial/ethnic groups combined.
	Seroprevalence was much higher among men who have sex with men, at 9.4%, in each racial/ethnic group.
	Other groups with higher than average HIV prevalence were:
	People with detectable herpes simplex type 2 (HSV-2) antibodies, at 1.9%; People who reported 50 or more lifetime sexual partners, at 3.4%; People who never married, at 0.8%.

Based on these findings, the study authors concluded, "In this household-based population, seroprevalence did not significantly change from NHANES III [1988-1994] to NHANES 1999-2006."

"Non-Hispanic blacks had significantly higher prevalence of infection compared with other race/ethnic groups," they added. "Male-to-male sex and the presence of HSV-2 antibody were the strongest predictors of HIV infection."

The overall prevalence rate in this study was lower that other national estimates, in part because household-based surveys do not include populations such as homeless people, individuals living in institutional settings including prisons, and military personnel.

In broader surveys, HIV prevalence has increased over time, which reflects not only changes in incidence (new infections), but also the fact that people are living with HIV longer and fewer are dying of AIDS due to effective antiretroviral therapy. It is unclear, therefore, why prevalence in the household-based population does not appear to have increased between 1988-1994 (pre-HAART) and 1999-2006 (post-HAART).

Department of Health and Human Services, Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD; Department of Health and Human Services, Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Atlanta, GA; Department of Health and Human Services, Northrop Grumman in support of Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Atlanta, GA.

1/26/10

Reference
GM McQuillan, D Kruszon-Moran, T Granade, and JW Feldman. Seroprevalence of HIV in the US Household Population Aged 18-49 Years: The National Health and Nutrition Examination Surveys, 1999-2006. Journal of Acquired Immune Deficiency Syndromes 53(1): 117-123 (Abstract). January 2010.