Detection by reverse transcription-polymerase chain reaction of influenza C in nasopharyngeal secretions of adults with a common cold

The lack of practical methods for a laboratory diagnosis of influenza C vir us infections and the seemingly benign nature of the virus contribute to th e fact that 50 years after its first isolation, relatively little is known about the epidemiology and the clinical impact of this virus. Reverse trans cription-polymerase chain reaction (RT-PCR) was used to amplify influenza C RNA fragments from clinical specimens. Two hundred otherwise healthy adult s with recent onset of a common cold were studied. Nasopharyngeal aspirates were collected at entry to the study and 1 week later. Serum samples for a ntibody determinations were obtained at the first visit and after 3 weeks. Influenza C was detected in 7 of the 200 patients by 2 different RT-PCR for mats. All 7 patients had a significant increase in antibody titers between serum samples collected during the acute and convalescent phases of the ill ness. Influenza C appears to be one of the many viruses that cause acute up per respiratory tract infections in adults.