[The prevalence of serological markers for the human immunodeficiency virus and the hepatitis B virus in a psychiatric hospital].

Objectives: To estimate the prevalence of antibodies to human immunodeficiency virus (HIV), antibodies to hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg), and antibodies to delta virus (anti-DV).

Design: Cross-sectional (prevalence) study. A non-proportional (stratified by length of stay) random sample of 20% of admitted patients was selected.

Clinical Setting: The Hospital Psiquiátrico Nuestra Señora de Montserrat (Sant Boi de Llobregat, Barcelona, Spain) admits about 670 patients in its short-term, rehabilitation (mid-term) and long-term wards.

Subjects: 139 patients were selected: 91% were males, mean age was 55 years, and 10% belonged to an HIV risk group; mean length of hospitalization since last discharge was 13 years.

Measurements: Blood samples were drawn in October, 1988. Anti-HBc, HBsAg and anti-DV were determined by competitive enzyme immunoassay (EIA). Anti-HIV-1 were determined by sandwich EIA; negativity of results with high absorbency but below the cut-off point was confirmed by Western blot.

Results: None of the sampled patients had circulating anti-HIV-1 antibodies. Four cases showing high absorbency (below the "cut-off" point) were ruled out by Western-blot. Overall, the prevalence of anti-HBc was 52.8% (54.4% in long-term wards, 35.0% in mid-term wards, and 13.8% in short-term wards). The prevalence of HBsAg was 2.3%, of anti-DV 1.5%, and of HDAg 0%.

Conclusions: Prevalence of anti-HIV is null in the studied institution. Current efforts to prevent HIV infection must continue; a hepatitis B vaccination program is highly warranted among patients and professionals of the studied hospital.