UCSF

Background

With use of polymerase chain reaction (PCR) and a centrifugation-enhanced viral culture method, we characterized the viruses causing acute respiratory infection in adults during an influenza season.

Methods

During January-March 2002, nasopharyngeal wash specimens from previously healthy adults presenting with respiratory symptoms were evaluated for viral pathogens with centrifugation-enhanced viral culture and PCR.

Results

The diagnoses in 266 cases included unspecified upper respiratory infection (in 142 [54%] of the cases), acute bronchitis (42 [16%]), sinusitis (23 [9%]), pharyngitis (22 [8%]), and pneumonia (17 [6%]). The use of a shell vial assay and PCR identified a pathogen in 103 (39%) of the patients, including influenza A or B in 54, picornavirus in 28 (including rhinovirus in 24), respiratory syncytial virus (RSV) in 12, human metapneumovirus in 4, human coronavirus OC43 in 2, adenovirus in 2, parainfluenza virus type 1 in 1, and coinfection with influenza and parainfluenza virus type 1 in 2.

Conclusion

Our findings demonstrate that, even during the influenza season, rhinovirus and RSV are prevalent and must be considered in the differential diagnosis of adult acute respiratory infection before prescribing antiviral medication. Human coronavirus and human metapneumovirus did not play a substantial role. PCR was an especially useful tool in the identification of influenza and other viral pathogens not easily detected by traditional testing methods.