Abstract
SUMMARY: A radial haemolysis test designed to detect antibody specifically directed against the neuraminidase is described and compared with currently available techniques for the routine diagnosis of infection with influenza viruses.Paired sera were available from two outbreaks of influenza A, one with the N1N1 subtype and the other with the H3N2 subtype. This technique confirmed diagnosis in 92% of cases diagnosed by other laboratory methods.