[Radial hemolysis in the diagnosis of influenza virus infections]

Some of the parameters of the radial haemolysis test were studied, and the test was used to determine antibody titres of sera obtained from patients involved in the epidemic outbreak of influenza-A/Port Chalmers, 1975. The sensitivity of the method was found to depend on the degree of erythrocyte sensitisation. An enlargement by 40 per cent of the haemolytic halo diameter should be considered and treated as antibody rise, if the reaction was to used in serological diagnosis under the conditions tested. The findings were in agreement with the complement fixation reaction in 48 per cent of all cases and with the haemagglutination inhibition test in 53.8 per cent.