Surveillance of AIDS
All 50 states, the District of Columbia, U.S. dependencies, possessions, and associated nations report AIDS cases to CDC using a uniform surveillance case definition and case report form. Cases in this report were reported according to the 2000 surveillance case definition [2].

Surveillance of HIV Infection (not AIDS)
This report includes case reports from 39 areas that had laws or regulations requiring confidential reporting by name for adults and adolescents with confirmed HIV infection (not AIDS), in addition to the reporting of persons with AIDS. Over time, HIV infection may progress to AIDS and be reported to surveillance. Persons with HIV infection (not AIDS) who are later reported as having AIDS are deleted from the HIV infection (not AIDS) tables and added to the AIDS tables.

Tabulation and Presentation of Data
Data in this report are provisional. This report includes information received by CDC through June 30, 2003. Data for the U.S. dependencies, possessions, and associated nations are included in the totals. The U.S. dependencies, possessions, and associated independent nations comprise Puerto Rico, the U.S. Virgin Islands, Guam, American Samoa, the Republic of Palau, the Republic of the Marshall Islands, the Commonwealth of the Northern Mariana Islands, and the Federated States of Micronesia.

Race and ethnicity
In the Federal Register for October 30, 1997 [3], the Office of Management and Budget announced the Standards for Maintaining, Collecting, and Presenting Federal Data on Race and Ethnicity, also known as Statistical Policy Directive 15. At a minimum, the following race categories should be collected: American Indian or Alaska Native; Asian; black or African American; Native Hawaiian or Other Pacific Islander; and white. Additionally, systems must be able to retain information when multiple racial categories are reported. Two ethnicity categories should be collected regardless of race: Hispanic and not Hispanic.

Because data for this report were compiled from reports to CDC through June 2003, race and ethnicity information may have been collected under two systems. The race and ethnicity categories in the system used through December 2002 are maintained in this report because most were under that system. Persons who reported multiple racial categories or whose race was unknown are included in the cumulative totals (Tables 1-4). Also, persons reported as non-Hispanic may include persons whose ethnicity was unreported.

Exposure Categories
For surveillance purposes, cases of HIV infection (not AIDS) and AIDS are counted only once in a hierarchy of exposure categories. Persons with more than one reported mode of exposure to HIV are classified in the exposure category listed first in the hierarchy. The exception is men who report sexual contact with other men and injection drug use; this group makes up a separate exposure category.

Persons whose exposure category is classified as male-to-male sexual contact include men who report sexual contact with other men (i.e., homosexual contact) and men who report sexual contact with both men and women (i.e., bisexual contact). Persons whose exposure category is classified as heterosexual contact are persons who report specific heterosexual contact with a person with, or at increased risk for, HIV infection (e.g., an injection drug user).

Adults and adolescents born in, or who had sex with someone born in, a country where heterosexual transmission was believed to be the predominant mode of HIV transmission (formerly classified as Pattern II countries by the World Health Organization) are no longer classified as having heterosexually acquired AIDS unless they meet the criteria stated in the preceding paragraph. Similar to other cases among persons who were reported without behavioral or transfusion risks for HIV infection, these cases are now classified (in the absence of other risk information that would classify them in another exposure category) as “no risk reported or identified” [4].

Cases in persons with no reported exposure to HIV through any of the routes listed in the hierarchy of exposure categories are classified as “no risk reported or identified.” No identified risk (NIR) cases include cases that are being followed up by local health department officials; cases in persons whose exposure history is incomplete because they died, declined to be interviewed, or were lost to follow-up; and cases in persons who were interviewed or for whom other follow-up information was available and no mode of exposure was identified.

References

• Lee LM, McKenna MT, Janssen RS. Classification of Transmission Risk in the National HIV/AIDS Surveillance System. Public Health Reports. 2003;118:400-407.
• CDC. Guidelines for national human immunodeficiency virus case surveillance, including monitoring for human immunodeficiency virus infection and acquired immunodeficiency syndrome. MMWR 1999;48(No. RR-13):29-31.
• National Archives and Records Administration. Revisions to the Standards for the Classification of Federal Data on Race and Ethnicity. Federal Register 1997;62:58781-58790. Available at: http://www.whitehouse.gov/omb/fedreg/ombdir15.html.
• CDC. Current trends: heterosexually acquired AIDS—United States, 1993. MMWR 1994; 43:155-160.