OBJECTIVE: This study was conducted to determine the seroprevalence of
HIV-1 antibodies among hospitalized homeless mentally ill patients. METHOD:
From December 1989 through May 1991 the authors collected discard blood
samples from patients consecutively admitted to a psychiatric unit
designated for the care of severely mentally ill persons removed from the
streets of New York City. The blood samples were tested for HIV-1
antibodies, and the results were analyzed for associations with age,
gender, ethnicity, male homosexual activity, and use of injected drugs.
RESULTS: The HIV seroprevalence was 6.4% (13 of 203 samples). Patients
between ages 18 and 39 accounted for 51.2% of the admissions and 84.6% of
the 13 positive results, a seroprevalence of 10.6% for this subsample.
Patients under age 40 were more than six times as likely to test positive
for HIV antibodies as those 40 or over. Ethnicity did not predict
seropositivity. Women were as likely as men to be infected. Although
clinicians had noted high-risk behavior on the charts for only three
(23.1%) of the 13 positive cases, a recorded history of use of injected
drugs was associated with a 6.5-fold greater risk of HIV seropositivity.
CONCLUSIONS: One in every 16 patients admitted to the special unit was HIV
positive. Age under 40 and use of injected drugs were strongly associated
with seropositivity. Because information on high-risk behavior was
infrequent, the reasons for younger patients' greater risk are unclear. The
homeless mentally ill require outreach efforts to reduce the risk of
acquiring or transmitting HIV.