Surveillance of 16 respiratory viruses in patients with influenza-like illness in Nanjing, China

Abstract

Much less is known about the etiology of influenza-like illness in China. A continuous surveillance of 16 respiratory viruses was conducted from November 2010 to October 2011 of outpatients with influenza-like illness in Nanjing, China. The two largest general hospitals and a provincial virus laboratory in Nanjing participated in this study. Throat swabs were collected from outpatients during medical visits for influenza-like illness and were tested for 16 respiratory viruses using PCR. Three hundred seventeen viruses were detected in samples from 246 (50.6%) patients with influenza-like illness. The viruses found mostly commonly were influenza, rhinovirus, hCoV HKU1, and adenovirus. The identification rates of respiratory viruses differed significantly among different sampling seasons (P = 0.0002). The rates of influenza A and hCoV HKU1 were much higher during the influenza-like illness winter peak than during the influenza-like illness summer peak and other months. Co-infections were detected in 57 (11.7%) patients and were found most commonly in adults older than 60 years. RSV was detected in 5.9% and 2.6% of patients who were 0-5 and 6-15 years old, respectively, but was not detected in other age groups. This study confirmed that multiple respiratory viruses may circulate concurrently in the population and account for a large proportion of influenza-like illness. In addition to influenza virus, hCoV HKU1 may be associated with the influenza-like illness winter peak in Nanjing, China.