HIV infection in psychiatric patients: an unlinked anonymous study

Recent surveys suggest that psychiatric patients are at increased risk of being infected with HIV, although very little information is available concerning the seroprevalence of HIV infection among this population outside the US. The aim of this study is to determine the seroprevalence of HIV-I among patients admitted to a psychiatric in-patient unit and to gather linked anonymous risk-factor information.

An unlinked serosurvey was made, using HIV-1 antibody testing of remnant blood specimens collected for routine medical purposes, of patients consecutively admitted to an acute psychiatric unit in Madrid.

Blood was obtained from 390 of the 477 eligible patients (81.8%). The prevalence of HIV was 5.1% (20/390). Patients aged between 18 and 39 accounted for 63.4% of the admissions and 75% of the positive results. Of the 29 patients who presented with injecting drug use, 14 were HIV-infected (48.3%; 95% CI 29.4 67.5). Of the 51 patients for whom any risk behaviour was noted on the admission chart, 18 were HIV-infected (35.3%; 95% CI 22.4 49.9).

This study demonstrates that there is a substantial prevalence of HIV infection in psychiatric patients admitted to an acute in-patient unit. History of injecting drug use was strongly associated with seropositivity. Clinicians recognised risk factors for HIV infection in the majority of the HIV-infected cases.