Influenza B-Associated Reye's Syndrome: Incidence in Michigan and Potential for Prevention

Abstract

Prospective surveillance for Reye''s syndrome in Michigan [USA] revealed the occurrence of 46 cases between Dec. 15, 1973 and June 1, 1974. To determine the incidence of influenze B-associated Reye''s syndrome, a randomized point-prevalence survey of 1041 schoolchildren was done in a county in Michigan where there were simultaneous outbreaks of influenza B and Reye''s syndrome. Of the children tested, 20% had titers of hemagglutination-inhibiting antibody to influenza virus B/Hong Kong/5/72 of .gtoreq. 1:20. Based upon this countywide survey, the incidence of Reye''s syndrome following influenza B was estimated at 30.8-57.8 cases of Reye''s syndrome/100,000 cases of influenza B. A detailed epidemiologic investigation of the patients who developed Reye''s syndrome indicated that the syndrome occurred 4 times more frequently in children living in rural areas than in antecedent viral infections such as influenza B, factor(s) that are most likely extrinsic or environmental also apparently play a role in the pathogenesis of Reye''s syndrome.