Echovirus type 7 outbreak in Northern Ireland during 1984.

During 1984, 118 patients with echovirus type 7 infection were diagnosed. The incidence in Northern Ireland was more than three times higher than the rest of the United Kingdom. The outbreak peaked in June and July, with the highest incidence in Belfast and the eastern part of Northern Ireland. All patients were sufficiently unwell to require hospital admission. Aseptic meningitis was the commonest illness (54.2%) followed by gastroenteritis (22.0%), respiratory tract infections (11.9%) and influenza-like illnesses (8.5%). Males (62%) were affected more than females and 50 patients (42%) were less than one year old. The present epidemic had features in common with four previous enterovirus epidemics, except that the under one year age group was predominantly affected and no family or street outbreaks were detected.