Clinical characteristics and viral etiologies of outpatients with acute respiratory infections in Huzhou of China: a retrospective study

Viruses are commonly found in patients with acute respiratory infections (ARIs). However, the viral etiologies and clinical characteristics of outpatients with ARIs are poorly understood in China. Here, we identified the viral etiologies in outpatients with ARIs in Huzhou, China. Our results indicated that of 426 outpatients, 246 were positive for viruses. Of them, 221 were positive for a single virus, including influenza A, which comprised H3N2 (28.5%) and pandemic H1N1 (2009) (19.0%), enterovirus (10.4%), and influenza B (8.6%). Other single viruses were detected at less than 8.0%. Twenty-five patients were positively coinfected with two viruses. The prevalent viruses in coinfections were rhinovirus and H3N2 virus (28.0%). Viruses were major pathogens in young children (< 5 years) (75.0%). Coinfections were prevalent in older adults (11.9%) and young children (9.5%). Virus-positive outpatients presented higher temperatures and more sore throat, fatigue and shortness of breath than virus-negative outpatients. ARIs and most virus detections peaked during the winter, but enteroviruses emerged between April and September. Viruses are major agents of ARIs among outpatients in Huzhou, China. There was a variation in the distribution of viruses across different age groups and seasons. These findings are beneficial for planning prevention and treatment services for outpatients with ARIs.