[Hepatitis B markers at 3 open centers for mentally retarded].

With the aim of investigating the prevalence of hepatitis B virus infection, we studied 161 mentally retarded patients with an age range of 1 to 56, in three open institutions from the Safor Area (Valencia). Some positive serum markers of HBV infection were found in 15 patients (9.3%). The mentally retarded older than 17, presented a prevalence of HBV markers (20.6%), in contrast to those under this age (1.1%) and against the control group (5.1%) (p < 0.001). HBsAg positive markers were found in three cases, representing 4.4% among the older than 17's, against 0.4% of the general population (p < 0.05). There was some positive correlation with personal history of hepatitis (p < 0.01) and severely handicapped patients (p < 0.05) an there was no association with sex, duration of stay and Down's Syndrome. Our results indicate that seropositive B prevalence is similar to the general population in the mentally retarded younger than 17 years old and higher from this age on, which confirms the need for active prophylaxis in the youngest of this collective. Reviewing the Spanish studies we observe a lower prevalence of HBsAg(carriers) and HBV markers in open institutions than in closed institutions.