Community-wide outbreak of enteroviral illness caused by echovirus 30: a cross-sectional survey and a case-control study

Abstract

Background: In June, 1997, 21 children from a single community in Germany were hospitalized with aseptic meningitis. An epidemiologic investigation was conducted to determine the extent of the outbreak and risk factors for illness.

Method: The extent of the outbreak was assessed with a cross-sectional survey of every 10th child listed in the town register among the 2240 town children < 16 years old. A case-control study determined risk factors for illness. Sixty-two cases were identified through the cross-sectional survey from hospitalized persons and from persons seen by local physicians. Controls were 114 asymptomatic persons identified from the cross-sectional survey.

Results: The overall attack rate was 16%, with the highest attack rates (24%) among the 6- to 8-year olds. Onsets occurred during a 37-day period. Among the 2240 town children <16 years of age, an estimated 353 met the case definition for enteroviral illness, 168 visited a doctor and 21 were hospitalized. Data from the case-control study indicated that contact with an ill household member [odds ratio (OR) = 6.3; 95% confidence interval (CI) 2.6 to 15.5], day-care attendance (OR = 2.6; 95% CI 1.1 to 6.2) and playground use, either two to three times per week (OR = 3.7; 95% CI 1.3 to 10.2) or daily (OR = 4.3; 95% CI 1.6 to 11.3), were risk factors for illness.

Conclusion: Echovirus 30 caused substantial morbidity during this community outbreak caused by person-to-person spread. Household contacts, day-care centers and playgrounds were prominent risk factors for transmission.