Molecular testing of 270 consecutive nasopharyngeal swab samples taken in May and June 2009 and 274 samples from patients hospitalized between July and December 2009 showed similar findings of respiratory viruses, with influenza A pandemic virus H1N1/09 being the most represented, followed by human parainfluenza virus type 3 and rhinoviruses. Statistical analyses suggested virus cocirculation in the absence of viral interference.
Frequency of detection of upper respiratory tract viruses in patients tested for pandemic H1N1/09 viral infection.