HIV Infection --- United States, 2005 and 2008

H. Irene Hall, PhD

Denise Hughes

Hazel D. Dean, ScD

Jonathan H. Mermin, MD

Kevin A. Fenton, MD, PhD

National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC

Corresponding author: H. Irene Hall, PhD, Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC, 1600 Clifton Road, MS E-47, Atlanta, GA 30333. Telephone: 404-639-2050; Fax: 404-639-2980; E-mail: ixh1@cdc.gov.

Approximately 1.1 million adults and adolescents are living with human immunodeficiency virus (HIV) infection in the United States, with 48,200--64,500 persons newly infected each year (1,2). At the beginning of the HIV epidemic in the United States in the early 1980s, the majority of persons with an HIV diagnosis were white men who have sex with men (MSM) (3,4). MSM continue to comprise a substantial proportion of persons newly infected with HIV, and the proportion of HIV infections among racial/ethnic minorities and women has increased (5). (These categories are not mutually exclusive.) Monitoring the burden of the epidemic among specific population groups provides guidance for targeting prevention and treatment efforts and allows assessment of intervention success.

HIV infection is a notifiable disease in all states and the District of Columbia (DC). Since 1982, all 50 U.S. states and DC have reported stage 3-HIV infection, acquired immunodeficiency syndrome (AIDS), to CDC in a uniform format. In 1994, CDC implemented data management for national surveillance of early-stage HIV infection integrated with AIDS case surveillance, at which time 25 states with confidential, name-based HIV surveillance began submitting de-identified case reports to CDC. Eventually, additional states implemented name-based HIV surveillance, and all states had implemented such surveillance by April 2008. CDC regards data from states with confidential, name-based, HIV surveillance systems as sufficient to monitor trends for HIV infection after 4 continuous years of reporting (5).

To determine the number of persons aged ≥13 years who received a diagnosis of HIV infection during 2005 and 2008, CDC analyzed data from the national HIV surveillance system reported through June 2009. Analysis was limited to the 37 states that had reported HIV cases since at least January 2005 to allow for estimation of diagnoses rates. Rates per 100,000 population were calculated for 2005 and 2008 by sex and race/ethnicity, with population denominators based on postcensal estimates from the U.S. Census Bureau (6). Disparities in HIV diagnosis rates were assessed by using relative percentage difference, a relative measure of disparity recommended by CDC's National Center for Health Statistics to compare variations (7). The relative percentage difference in HIV diagnosis rates was calculated for each racial/ethnic group, using the rates among whites as the referent ([{rate of interest -- rate among whites} / rate among whites] × 100). Rates were compared with whites as the referent group because whites typically have the lowest or second-lowest diagnosis rates, and the numerator provides a stable rate. Percentage difference also was calculated for males compared with females by using females as the referent population (7). For transmission categories, analysis was limited to all men and MSM as a result of the availability of denominator data (8); the category of all men was used as the referent group. MSM denominator was calculated by using data on reports of the proportion of men who engaged in same-sex behavior during the previous 5 years and by using the point estimate (4.0%); however, the denominator might vary (95% confidence interval = 2.8--5.3) (8). Analyses were adjusted for reporting delays (i.e., the time between diagnosis and report) and for missing risk factor information (5). Data were not available for all states, so a state breakdown of disparities is not provided. Because data on income, education, and disability status were not available, these factors were not included in the analysis.

In the 37 states for which data were analyzed, a total of 35,526 persons aged ≥13 years received a diagnosis of HIV in 2005, and 34,038 received such a diagnosis in 2008. During 2008, the relative percentage difference in the HIV diagnosis rate among blacks/African-Americans compared with whites was 799%; the next highest differences were among Hispanics/Latinos (205%), Native Hawaiians/Other Pacific Islanders (NH/OPI) (178%), persons reporting multiple races (72%), and American Indians/Alaska Natives (AI/ANs) (45%) (Table). Asians had a lower HIV diagnosis rate than whites (relative percentage difference: -12%). During 2005--2008, rates of diagnoses of HIV infection among AI/ANs, Asians, and blacks/African-Americans increased, with a change in the relative percentage difference of 16%, 12%, and 46%, respectively. The rates among Hispanics/Latinos, NH/OPIs, and persons reporting multiple races decreased, with a decrease in the relative percentage difference because the rate among whites remained stable. In 2008, the relative percentage difference of HIV diagnoses among males compared with females was 212%, and the rate among males increased during 2005--2008, with a change in the relative percentage difference of 24%.

Although the racial/ethnic disparities in rates of HIV diagnoses among males are similar to the disparities observed for the racial/ethnic groups overall, more pronounced differences occurred among females. In 2008, among females, the relative percentage difference in HIV diagnosis rates compared with whites was 1,831% for blacks/African-Americans, 359 for Hispanics/Latinos, 266 for NH/OPIs, 310 for persons of multiple races, 138 for AI/ANs, and 3% for Asians. However, during 2005--2008, the relative differences decreased for all racial/ethnic females, compared with whites. The largest relative percentage difference was observed for MSM compared with all other men (6,408% in 2008), as well as the largest change from 2005 to 2008 (1,218%).

The data presented in this report are subject to at least four limitations. First, HIV infection diagnoses might reflect both HIV incidence and testing patterns; therefore, a person might receive a diagnosis close to or many years after acquiring an HIV infection. Second, data were unavailable from certain states. According to the number of AIDS cases diagnosed through 2008, the 37 states for which data were used represent approximately 68% of AIDS diagnoses throughout the 50 states and DC. Certain areas with historically high AIDS morbidity that have not conducted confidential, name-based HIV surveillance since January 2005 (e.g., California, Illinois, and Maryland) were not included, and thus the results might not be nationally representative. Third, for transmission categories, denominator data were available for MSM only; when denominator data for injection-drug users and heterosexuals become available in the future, disparities among these groups also can be estimated. Finally, adjustment for reporting delays might be inaccurate and result in less stable rates for the latest years.

Racial/ethnic minorities, except Asians, continue to experience a disproportionate burden of HIV infection diagnoses, as do MSM. The disparities continue to widen among black/African-American and AI/AN males, compared with white males. Although differences are narrowing among other males and females, ongoing and culturally appropriate intervention is needed to address these disparities. In addition, the increasing HIV infection rates among MSM highlight the need for expanded prevention efforts. Interventions should continue to target behavior risk factors and include structural interventions to address social determinants of health to reduce health disparities and promote health equity. Information regarding proven behavior interventions for high-risk populations has been published (9,10). Person-to-person behavior interventions for MSM can be implemented at the individual, group, and community level. Components can include providing information and skill-building to change knowledge, attitudes, beliefs, and self-efficacy (10).

References

1. CDC. HIV prevalence estimates---United States, 2006. MMWR 2008;57:1073--6.
2. Hall HI, Song R, Rhodes P, et al. for the HIV Incidence Surveillance Group. Estimation of HIV incidence in the United States. JAMA 2008;300:520--9.
3. CDC. Current trends update on acquired immune deficiency syndrome (AIDS)---United States. MMWR 1982;31;507--8; 513--4.
4. CDC. Acquired immunodeficiency syndrome (AIDS). Weekly surveillance report---United States. Atlanta, GA: US Department of Health and Human Services, Public Health Service, CDC; 1983. Available at http://www.cdc.gov/hiv/topics/surveillance/resources/reports/pdf/surveillance83.pdf.
5. CDC. Diagnoses of HIV infection and AIDS in the United States and dependent areas, 2008: HIV surveillance report. Vol 20. Atlanta, GA: US Department of Health and Human Services, CDC; 2010. Available at http://www.cdc.gov/hiv/surveillance/resources/reports/2008report/index.htm.
6. US Census Bureau. Population estimates: entire data set; July 1, 2008. Washington, DC: US Census Bureau; 2009. Available at http://www.census.gov/popest/archives/2000s/vintage_2008.
7. Keppel K, Pamuk E, Lynch J, et al. Methodological issues in measuring health disparities. Vital Health Stat 2 2005;141:1--16.
8. Purcell DW, Johnson C, Lansky A, et al. Calculating HIV and syphilis rates for risk groups: estimating the national population size of men who have sex with men [Latebreaker no. 22896]. Presented at the 2010 National STD Prevention Conference, Atlanta, Georgia; March 10, 2010.
9. CDC, HIV/AIDS Prevention Research Synthesis Project. 2009 compendium of evidence-based HIV prevention interventions. Atlanta, GA: US Department of Health and Human Services, CDC; 2009, Available at http://www.cdc.gov/hiv/topics/research/prs/evidence-based-interventions.htm.
10. Task Force on Community Prevention Services. The guide to community preventive services. New York, NY: Oxford University Press; 2005.

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