The drug-related AIDS epidemic in the United States

AIDS data are from a special tabulation from the Centers for Disease Control.  Injection-related AIDS cases include persons in the following risk groups: persons who inject drugs; men who have sex with men and inject drugs; and the heterosexual partners of persons who inject drugs.  AIDS cases are rounded to the nearest hundred.  

Injection-related AIDS rates per million for states were calculated using injection-related AIDS cases among persons age 13 and over (the 3-year average for the years 1996-1998) divided by the 1997 population age 13 and over.  The 3-year average was used to smooth out any unusual variations from year to year and to get a more realistic final figure. When ties occurred in state rates, the states involved were given the same rank.

U.S. population data are from the U.S. Bureau of Census.  The population of Puerto Rico age 13 and over was estimated using total population data from the U.S. Bureau of the Census and the projected age distributions from Eduard Bos, My T. Vu, Ernest Massiah, and Rodolfo A. Bulatao, World population projections 1994-1995.  Baltimore: Johns Hopkins Press, 1994, page 410.  

The percentage of AIDS cases that are injection-related was calculated by dividing the number of injection-related AIDS cases (the 3-year average from the years 1996-1998) by the number of AIDS cases for which the exposure group is known (also a 3-year average from the years 1996-1998).  Each percent is rounded to the nearest 5.  Thus, for example, 42 percent was rounded to 40.

Injection-related AIDS rates per million for metro areas were calculated using injection-related AIDS cases among persons age 13 and over (the 3-year average for the years 1996-1998) divided by the total 1997 population (including those age 12 and under). Population data are from the U.S. Bureau of Census.  When ties occurred in rates, the metro areas involved were given the same rank.  

Injection-related AIDS rates per million by race/ethnic group for each state were calculated using injection-related AIDS cases among persons age 13 and over for each racial/ethnic group (the 3-year average for the years 1996-1998) divided by the 1997 population  age 13 and over for that racial/ethnic group.  In instances when the ratio of AIDS rates for African Americans to whites or Latinos to whites was greater than 20, the ratio is reported as "greater than 20" rather than given as the exact ratio. Rates are not reported when the total number of AIDS cases for 1996-1998 was less than 100.   

Scott D. Holmberg, "The Estimated Prevalence and Incidence of HIV in 96 Large US Metropolitan Areas," American Journal of Public Health, May 1996, vol. 86, no. 5. Supplementary Material.  Available from the CDC.  An estimate of injecting drug use in the past year (244,000 in 1997) is also available, but is likely to be much less accurate than Holmberg's estimates because it is limited to only one year and because it does not include an estimate of the sexual partners of injecting drug users. See Substance Abuse and Mental Health Services Administration.  National Household Survey on Drug Abuse: Population Estimates 1997, July 1998, p. 104.

Following the practice of the CDC, the total of 240,000 injection-related AIDS cases for the United States as a whole includes injection-related AIDS cases among Puerto Rican residents (about 14,900).