Introduction
ARTI is the leading cause of morbidity and mortality in young children.1 In 2015, 138 million ARTI cases, 22 million severe ARTI cases and 0.9 million ARTI deaths occurred globally. The majority of ARTI can be attributed to viral infection, and among diverse respiratory viruses, respiratory syncytial virus (RSV), ADV, influenza (Flu) and parainfluenza virus (PIV) are the most common ones.2-5 According to WHO statistics, RSV infection causes 3.2 million people to be hospitalized, and 1/15 of them eventually die.6 Flu, with an obvious seasonality in positive infection rate, accounts for 7% of ARTI cases, 5% of ARTI hospital admissions, and 4% of ARTI deaths in children <5 years.7 ADV infection can be seen all the year round, accounting for 5% to 10% of lower respiratory tract infections in children.8
After the outbreak of SARS in 2003, China Information System for Disease Control and Prevention (CISDCP), the notifiable disease reporting system, was overhauled. However, the sudden emergence of SARS-CoV-2, highlighted new threats and need for more effective surveillance.9 The real time broadcast of virulent viruses such as SARS-CoV-2 during the outbreak raised the awareness that the epidemic of common clinical respiratory viruses such as RSV, ADV and Flu should also be monitored and reported because they also cause great health burden. Moreover, the broadcast of many infectious diseases often covered the overall situation of the whole country, lacking epidemic situation in specific provinces or cities. In addition, the data obtained were often confirmed positive severe cases reported by local medical institutions, but many mild outpatient cases have not been included, resulting in the loss of some positive data. Therefore, it’s quite important to review and update the epidemiological characteristics of respiratory viruses in our region.
A comprehensive and up-to-date epidemiological data on viral ARTI would be vital for clinical management especially in warning the possible time of the next outbreak of the respiratory viruses.10Furthermore, it provides clinicians with priority for virus detection in children, because early identification of virus can reduce the treatment time by 2.5 to 4 days.11 Therefore, we conducted a retrospective study on the detection results of respiratory viruses in children with ARTI, aiming to determine the etiologies of viral ARTI in west China. Through the analysis of the prevalence of the seven respiratory viruses in the past two years, we want to find out the susceptible population of respiratory viruses, the common types of viruses, the epidemic season and the changes of the viral positive rate before and during the outbreak of SARS-CoV-2.