per 100,000 population), and Maryland (29.5 cases per 100,000 population) (see Figure A.5). These figures compare with the national AIDS incidence rate in 1999 of 16.7 cases per 100,000 population (CDC, 2000b).
Historically, AIDS cases have been largely concentrated in urban areas. In 1999, 79 percent of AIDS cases were diagnosed in metropolitan areas with populations of 500,000 or more. Ten metropolitan areas (New York City, Los Angeles, San Francisco, Miami, Washington, D.C., Chicago, Houston, Philadelphia, Newark, and Atlanta) accounted for almost half of the cumulative reported AIDS cases. In terms of new AIDS cases per 100,000 persons, the most heavily affected metropolitan areas in 1999 were New York City (72.7 per 100,000), Miami/Ft. Lauderdale (65.3 and 61.2 per 100,000, respectively), Columbia, S.C. (54.6 per 100,000), and San Francisco (50.8 per 100,000) (CDC, 2000b).
While the U.S. epidemic has been perceived largely as an urban phenomenon, AIDS cases in rural areas have been among the most rapidly rising subset of the new cases reported to the CDC. The fastest growing rural epidemic is in the South, followed by the Northeast, the West, and the Midwest. As a proportion of the total cases, heterosexual transmission is more common in small town/rural settings than in urban sites; women and racial and ethnic minorities represent a substantial subset of nonurban cases (Wortley and Fleming, 1997; Graham et al., 1995).