[Assessment of the sensitivity of immunoprecipitation for the serodiagnosis of influenzal-bacterial pneumonias].

A comparative examination of 226 paired sera from patients with pneumonia was carried out by CFT, HI, neuraminidase activity inhibition (NI) and double immunodiffusion. A correlation of the results of agar gel precipitation and the CFT and HI tests was observed. Convalescent sera contained antibody to influenza virus ribonucleoprotein frequently, less so to its neuraminidase or hemagglutinin. The precipitation test was shown to be highly sensitive, easy to perform, and therefore should be used in examinations of sera from patients with influenza-bacterial pneumonia.