Most cases continue to be reported among residents of large cities.
AIDS cases have been classified into groups at greatest risk of acquiring the disease. Classification is an essential element of any epidemiologic investigation and serves such purposes as formulating prevention recommendations, providing direction for research, and identifying medical needs. However, the classification of certain groups as being more closely associated with the disease has been misconstrued by some to mean these groups are likely to transmit the disease through non-intimate interactions. This view is not justified by available data. Nonetheless, it has been used unfairly as a basis for social and economic discrimination.