Prevalence of human parainfluenza virus in patients with acute respiratory tract infections in Beijing

Objective To understand the incidence of human parainfluenza virus (HPIV) infection in patients with acute respiratory tract infections in Beijing and discussed the epidemiological characteristics of HPIV infection. Methods The throat swabs or sputum samples from acute respiratory tract infected patients were collected in five sentinel hospitals during 2011-2014. HPIV 1-4, and other common respiratory viruses, including influenza virus, bocavirus, rhinovirus, respiratory syncytial virus, enterovirus, adenovirus, human coronavirus, metapneumovirus, were detected by using multiplex real time-PCR. The results were analyzed with SPSS 17.0. Results A total of 217 HPIV positive samples were found from 3978 clinical samples (5.46%). The positive rate of HPIV3 was highest (2.21%) and the positive rate of HPIV2 was lowest (0.83%). For the detection of other respiratory viruses, the positive rate influenza virus was highest (12.27%, 488/3978). The age group 5 years had the highest positive rate of HPIV (7.75%) and followed by the age group 60 years and the age group 6-15 years had the lowest positive rate of HPIV. The positive rates of HPIV1 and HPIV3 declined year by year during 2011-2013 and increased in 2014,while the positive rate of HPIV2 showed a biennial trend and there were no obvious annual trend for HPIV4. The positive rate of HPIV during June-August was significantly higher than that in other months. There was no significant difference in the incidence between the upper and lower respiratory infection cases. Conclusion HPIV1 and HPIV3 were predominate in Beijing,2011-2014. Infants were the population at high risk of HPIV infection. The circulating types and related intensity varied with year and the type-specific seasonal patterns were different.