ISOLATION OF INFLUENZA-C VIRUS DURING AN OUTBREAK OF INFLUENZA-A AND INFLUENZA-B VIRUSES

During the winter of 1996 to 1997 two cases of influenza C were confir med, one by isolation and the second by serology (fourfold increase in hemagglutination inhibition antibodies), The cases of influenza C occ urred during an outbreak of influenza A (H3N2) and B viruses. The posi tive isolation was from one of three throat washings sent to the labor atory, and the other case was from a group of 51 students participatin g in a study of influenza virus vaccination. It seems, therefore, that influenza virus should also be considered when examining patients wit h respiratory infections during the influenza season.