APPLICATION OF IMMUNOFLUORESCENCE IN THE DIAGNOSIS OF INFLUENZA FROM THROAT WASHINGS

Abstract

Indirect immunofluorescent staining provides a valuable tool for the rapid diagnosis of influenza from throat washings. In 73 throat washings tested for the presence of Asian influenza virus by egg inoculation and by immunofluorescence, identical results were obtained by both methods. Although cross reactions were noted between strains within the type, the strain-specific reaction could be easily distinguished by a greater intensity of the fluorescence. The immunofluorescent technique has a great advantage over the isolation procedure since the results of the examination could be reported within 4–5 hours after arrival of the specimens in the laboratory. The technique is, of course, applicable only when a known type of influenza virus or a new strain antigenically related to the known strains is involved in the outbreak.