Viral hepatitis: enzyme assays and serological procedures in the study of an epidemic

In the study of an epidemic. Am J Epidemiol 106:493-501, 1977. An epidemic of viral hepatitis beginning In late 1975 In a residence for multiply handicapped children, recognized very early in Its course, was Inves-tigated pro8pectively to permit comparison of enzymatic and serologic tests. Thirty-three residents of the Institution and 46 full- and part-time employees were studied by the immune adherence hemaggiutination procedure for anti-body (anti-HAV) to hepatitis A virus (HAV). Of these, 31 residents and 37 staff members were susceptible at the beginning of the epidemic. Nineteen and six, respectively, had anti-HAV seroconversion Indicating HAV Infection. Thus, 12 children (39%) and 31 staff members (81%) of presumed susceptibies did not have serologic evidence of Infection. The subcllnlcal/cllnlcal ratio for the children was 1.1:1; for personnel, it was 1:1. Serum alanlne amlnotrans-ferase (ALT) levels compatible with viral hepatitis occurred In 21 persons (84%) who had anti-HAV seroconversion; conversely, there were 10 persons who had ALT abnormality without detectable anti-HAV In late specimen