Abstract
During an epidemic-free period of nearly 2 years infections and illnesses were followed in a group of small children (2–3½ years) in a day nursery. The incidence of illness was fairly low, 6.3 per child and year. The viral infections were followed by means of the inclusion reaction in the urine and isolation of virus, and the bacterial by culture of nasal secretion. In 60% of the cases the viral infection was accompanied by illness. In 57 cases of illness there were 27 (47%) with merely virus and/or inclusion reaction, 8 (14%) in which bacteria alone were discovered, and 22 (39%) with both. The viral infections were the decisive ones in about 80% of the illnesses. Enteric respiratory viruses of 10 types were detected. 16 (73%) of the 22 children had such an infection on at least one occasion, and spread within the group occurred on infection with echovirus 9, coxsackievirus B 4 and reovirus. Enteric viruses accounted for 29% of the viral infections. Streptococci and Mycoplasma pneumoniae played no part in the bacterial infections, which were entirely dominated by pneumococci. Cytomegaloviruria was found in 13 (72%) of 18 children examined. No spread was detected within the group. Rotavirus was on no occasion found in faeces.