The HIV/AIDS epidemic was first recognized in the United States in 1981. Since that time, all states have conducted AIDS surveillance by using a standardized, confidential name-based reporting system. Since 1985, many states have also implemented HIV case reporting as part of their comprehensive HIV/AIDS surveillance programs. AIDS is the end stage of the natural history of HIV infection, and treatment advances since the mid-1990s have diminished the capacity of AIDS surveillance data to accurately represent the trends in the incidence of HIV infection or the need for prevention and care services (increasingly, AIDS data represent late diagnosis of HIV disease, lack of access to effective therapies, or treatment failures). As of January 1, 2006, 44 states and territories had laws or regulations requiring the reporting of adults, adolescents, and children with confirmed HIV infection by using a confidential name-based reporting system (the same as the AIDS reporting system for all jurisdictions in the United States).

To best direct resources toward communities with the greatest need, health planners often establish priorities by comparing the magnitude and effect of the epidemic between 2 areas. Because not all jurisdictions use the same confidential named-based surveillance system to collect data on cases of HIV infection and cases of AIDS, only AIDS data are presented in this report. In future reports, when all jurisdictions use the same system to collect HIV data and AIDS data, the geographic areas (states, territories, and associated nations) and the metropolitan statistical areas (MSAs) will be ranked by reported cases of HIV infection as well as by reported cases of AIDS.

This report presents the number of AIDS cases in adults and adolescents aged 13 years or older that were reported during 2004, cases reported during 1981–2004, case rates (cases reported per 100,000 population), and estimates of AIDS prevalence as of December 31, 2004, for areas (Table 1) and MSAs with a population of 500,000 or more (Table 7) in the United States. Data are stratified by sex (Tables 2 and 8), race/ethnicity (Tables 3, 4, 9, and 10), and transmission category (Tables 5, 6, 11, and 12) for areas and MSAs. The cumulative numbers of AIDS cases (1981–2004), the numbers of new AIDS cases reported during 2004 (incidence) (Tables 5, 6, 11, and 12), and the numbers of persons living with AIDS as of December 31, 2004 (prevalence) (Tables 1–4 and 7–10), are based on reported AIDS cases (or deaths); these data have been adjusted for reporting delays. Additionally, the data in Tables 5, 6, 11, and 12 have been adjusted for the redistribution of AIDS cases in persons initially reported without an identified risk factor.

In all tables, areas are ranked in descending order of the number of AIDS cases (see Technical Notes); the numbers should also be considered in the context of the population size of each area or MSA. Tables 1 and 7 include AIDS case rates (cases reported per 100,000 population) to allow for such comparisons. Ranking areas by AIDS rates shifts the order of the areas, moving some of the smaller jurisdictions such as Puerto Rico, the U.S. Virgin Islands, and Delaware to higher positions on the list. Rates for areas with small populations are unstable and should be interpreted with caution.

The following are highlights of this report.

• In most of the area tables, New York, Florida, California, Texas, and New Jersey ranked highest in the number of AIDS cases reported during 2004.
• New York ranked first in the reported numbers of black (not Hispanic) adults and adolescents with AIDS (cumulative number of cases, number of cases reported during 2004, and number of persons living with AIDS).
• Puerto Rico ranked second in the cumulative number of cases in female Hispanics and third in cases in male Hispanics.
• Hawaii ranked third in the cumulative number of cases in Asian/Pacific Islander adults and adolescents.
• Arizona, Oklahoma, Washington, and Alaska ranked high in the cumulative number of cases in American Indian/Alaska Native adults and adolescents.
• In most MSA tables, New York City, Los Angeles, Miami, Washington, DC, and Chicago ranked highest in the cumulative number of cases and the number of cases reported during 2004.