[Epidemiology, clinical data and immune response of an epidemic of hepatitis A (author's transl)].

Almost all members of an affected family (46 persons) were followed up for a year after contracting hepatitis A during an epidemic in a rural area. Sixteen children, one juvenile and a 42-year-old woman had been infected. A mild subclinical course was present in about a third. All but one person in the studied population who were over 25 years had antibody titres from an earlier hepatitis A infection. As result, those who fell ill were almost exclusively children and juveniles with an average age of 15 years. Contagion rate within the family was 56.7% for those not immunised. Antibodies against hepatitis A virus of the IgG class rose in the majority of patients between the sixth and twelfth month of the infection. There was a significant correlation between the titre after one year and maximal GPT and bilirubin levels in the acute phase of the illness.