Antibody to hepatitis A antigen in institutionalized mentally retarded patients
W. Szmuness, R. H. Purcell, J. L. Dienstag and C. E. Stevens
Institutionalized patients with Down syndrome and matched controls with
other causes of mental retardation were tested by immune adherence
hemagglutination for the presence of antibody to hepatitis A antigen
(anti-HA). Altogether 75.1% (175 of 233) exhibited presence of anti-HA,
with no differences by sex or age. Patients reactive for hepatitis B
surface antigen (HBsAg) or its antibody (anti-HBs) were reactive for
anti-HA significantly more frequently than those with a negative reaction
for these markers. In contrast to serologic markers of hepatitis type B,
prevalence of anti-HA does not depend on the cause of mental retardation or
on the age at primary infection. The rate of anti-HA positivity was found
to be closely correlated with duration of institutionalization. The study
confirmed that many closed institutions for the mentally retarded are
hyperendemic for hepatitis type A and that formation of anti-HA is not
greatly affected by either immune deficiency or immune immaturity.