Fecal excretion of Greek strains of hepatitis A virus in patients with hepatitis A and in experimentally infected chimpanzees.

The presence of hepatitis A virus (HAV) in stool samples was determined in 36 children (mean age, 8.9 years) and 38 adults (mean age, 19.9 years) with acute type A hepatitis. Three stool samples, taken on admission and thereafter at three-to-five-day intervals, were collected from each patient. The first day of dark urine was considered to be the onset of illness. Molecular hybridization of cloned HAV cDNA to fecal extracts was used to detect HAV RNA; radioimmunoassay was used to detect HAV antigen. In all of the samples tested, HAV RNA was detected significantly more frequently than HAV antigen (28.4% vs. 8.1%, P less than .001). HAV RNA was detected with equal frequency in both children and adults during the first week of illness. However, HAV RNA was detected more frequently in children than in adults during the second week of illness (45.7% vs. 18.9%, P less than .05). Among patients with HAV RNA, detection in multiple samples was more frequent in children than in adults (38.9% vs. 7.9%, P less than .01), especially among males.