Liver function abnormalities in the course of a type A (H1N1) influenza outbreak: relation to Reye's syndrome.

In the course of the A/Brazil (H1N1) outbreak of 1978-1979, two cases of Reye's syndrome occurred in Grayling, Michigan, an area with a county-wide population of 2056 school age children. School absenteeism peaked at levels between 16-28 per cent. Clinical histories and paired blood specimens were collected from 860 school children; the initial blood was obtained shortly after the peak of the outbreak. Serologic results confirmed that type A H1N1 virus was the cause of the outbreak. Serum alanine aminotransferase (SGPT) and creatine phosphokinase (CPK) values were determined on all initial blood specimens and a sample of the second specimens. CPK results did not correlate with infection, illness or SGPT values. SGPT values of 60 IU/l or greater were found in 1.5 per cent of those tested. The elevated values were not associated with illness but were associated with influenza infection. Based on the excess number with elevated results in those with recent infection, it is estimated that at least 2.7 per cent of individuals infected by type A (H1N1) influenza had associated elevated SGPT.