Seroprevalence for the hepatitis B and C viruses in a psychiatric institution.

Many patients admitted to psychiatric institutions have a history of risk f actors for contamination with the hepatitis B and C viruses (HBV and HCV). Immunization policies for psychiatric institution patients are not widely k now. A study conducted in a 600-bed psychiatric institution in Paris, Franc e, to evaluate the proportion of potentially contaminating patients at admi ssion, as well as immunization use in HBV-negative patients. Serologic mark ers for the HBV and HCV were looked for prospectively in all patients admit ted over a two-month period. Immunization use was evaluated in the patients who had a first serologic test in 1995 or 1996 and follow-up tests until t he end of 1997. The prospective part of the study demonstrated preadmission exposure to the HBV in 23.0 +/- 6.0% of patients. This proportion was larg er in men (26.0%) than in women (14.8%), although the difference was not st atistically significant (P=0.10). Four patients (2.0%) tested positive for the HbS Ag. Among the HBV-negative patients, 13.0% received the vaccine; al l had protective antibody levels. These patients were younger and more like ly to be first-time admissions (18.4% vs 3.6%, P<0.01). HCV seroprevalence was 6.0%. Serologic tests for the HBV were requested for 327 patients betwe en Januar 1995 and december 1996. Among the patients who were seronegative at admission and received follow-up at the study hospital, only 13.8% were immunized at this hospital. Of the HCV-positive subjects, 63.3% were also H BV-positive. None of the HCV-positive HBV-negative subjects received immuni zation subsequently. Six to eight per cent of patients admitted to the stud y hospital are potentially contaminating for the I-IBV or HCV The level of hepatitis B vaccine use is too low, particulary in high-risk patients. Thes e data indicate a need for policies aimed at effectively preventing HBV and HCV transmission (information, education, immunization campaigns), both du ring the psychiatric institution stay and after discharge.