Two new serotypes of enteric adenovirus causing infantile diarrhoea.

Fastidious enteric adenovirus have recently been recognized as an important cause of acute gastroenteritis in young children. Their inability to grow in vitro has hampered classification by conventional methods. With modern immunological and chemical techniques the enteric adenoviruses have been shown to be distinct from the 39 established human adenovirus serotypes. In a prospective study of the viral, bacterial and parasitic aetiology of acute gastroenteritis 410 children and 205 age-matched controls were studied. An enteropathogenic agent was detected in 67% of the diarrhoeic patients and 57% were of viral origin. Rotavirus was the major agent found in 43% of the patients whereas adenovirus was found in 13%. Of the 50 adenovirus specimens, so far fully characterized by electron microscopy, ELISA-assays, DNA-restriction analysis and isolation studies 70% were identified as enteric adenoviruses. Two serotypes, adeno 40 and 41, were detected representing the new subgroups F and G. Twelve of 17 paired serum specimens, from children with enteric adenovirus showed a significant rise in hemagglutination inhibition titers. Infection with enteric adenoviruses showed 2 small seasonal peaks in summer and late winter. Infection occurred early in life, 85% of the children aged less than 3 years. Diarrhoea was the main symptom with an average duration of 9 days. Adenovirus type 41 seemed to cause diarrhoea of longer duration. Fever and vomiting was mild with a mean of 2 days. Respiratory symptoms occurred in 20% of the cases. The incubation period could be estimated as 7 days. Virus was excreted for 10-14 days.