Objectives: Homeless persons have an increased risk of HIV infection b
ecause of a high prevalence of HIV-related risk behaviors. These inclu
de drug use, sexual contact with persons at risk for HIV infection, an
d the exchange of sex for drugs. The objectives of this investigation
were to describe HIV seroprevalence rates in homeless adults and runaw
ay youth. Methods: In 1989, the Centers for Disease Control and Preven
tion began collaboration with state and local health departments to co
nduct HIV seroprevalence surveys in homeless populations. Unlinked HIV
seroprevalence surveys were conducted in 16 sites; 11 provided medica
l services primarily to homeless adults, and five to runaway youth age
d <25 years. Results: From January 1989 through December 1992, annual
surveys were conducted in 16 sites in 14 cities. Site-specific seropre
valence rates ranged from 0-21.1% (median, 3.3%). Among homeless adult
s in three sites, rates were higher among men who had sex with other m
en and those who injected drugs than among persons with other risk exp
osures (28.9 versus 5.3%). In general, rates were higher for heterosex
ual men than for women and higher among African Americans than whites.
In sites providing services to homeless youth, HIV seroprevalence rat
es ranged from 0-7.3% (median, 2.3%). Conclusions: These data indicate
that HIV infection among homeless adults and runaway youth is an impo
rtant public health problem. HIV prevention and treatment should be in
tegrated into comprehensive health and medical programs serving homele
ss populations.