Epidemiological features of type 22 echovirus infection.

During a 25-year observation period, isolates of type 22 echovirus were obtained from 109 patients. 92% of the patients were < 2 years old. Echovirus type 22 was isolated with peaks both during late summer and autumn, as enterovirus infections, and during the winter months and early spring, as respiratory viruses. Diarrhea was the most common symptom, followed by obstructive bronchitis and, less often, CNS symptoms. Nosocomial infections were common. In a noticeable number of the children, maternal neutralizing antibodies were most probably present at the time of infection. The epidemiologic features of type 22 echovirus infections with regard to age and seasonal distribution, contagiousness and a relative lack of protection by neutralizing antibodies differed from most enterovirus infections.