Abstract
During the period 1986-1991 in Okinawa, Japan, serologic markers of hepatitis B virus infection (hepatitis B surface antigen : HBsAg, antibody to hepatitis B core antigen : anti-HBc), hepatitis C virus infection (antibody to HCV : anti-HCV) and human T lymphotropic virus type (antibody to HTLV-I: anti-HTLV-I) were investigated in institutionalized mentally retarded patients. In 1986, HBsAg was detected in 34(9.1%), anti-HBc in 179(48.0%), anti-HCV in 5(1.3%)and anti-HTLV-I in 34(9.1%) of 373 patients. HBsAg and anti-HBc were more prevalent in patients than in the 400 controls (3.8%, p<0.05, 25.5%, p<0.001, respectively). However, there was no significant difference in the prevalence of either anti-HCV or anti-HTLV-I between patients and controls (1.0%, 9.0%, respectively). Eight (12.5%) of 64 seronegative patients not given hepatitis B vaccine were infected with hepatitis B virus (one became an HBsAg carrier)over five years of observation, whereas none were infected with hepatitis C virus or HTLV-I.Hepatitis B virus was the most transmissible of the three viruses among the mentally retarded patients in these institutions.
