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

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.