[Epidemiological characteristics of in cases with acute respiratory infection in Beijing, 2015-2019].

To analyze the epidemiological characteristics of infection among patients with acute respiratory infection in Beijing from 2015 to 2019. The epidemiological data of acute respiratory infection patients from 35 sentinel hospitals in Beijing were collected by the respiratory pathogen surveillance system in Beijing. The clinical samples were collected to detect , and the sequence of the VD4 region of the gene in positive samples was analyzed. From January 2015 to December 2019, the overall positive rate of among patients with acute respiratory infection in Beijing was 0.34% (129/37 460). The positive rate of generally increased in March, reaching the peak in May, and started to drop in July, with a duration of about 5-8 months. The epidemic season in different years fluctuated by 1-2 months. The positive monthly rate of was no less than 0.30% in every epidemic season. The positive rate of was the highest in the 5-44 years old group and the highest in 10-14 year-olds. The risk of infection increased with age in patients younger than 25 years old and decreased in those older one aged than 25 years of age. The positive rates in male and female patients were 0.33% (68/20 830) and 0.37% (61/16 528), respectively, and there was no significant difference between the two groups (=0.486, =0.486). The positive rate of in patients with common pneumonia was higher than that in patients with upper pneumonia and severe pneumonia (=36.797, <0.01). Other respiratory pathogens were also detected in the samples, and the top four pathogens appeared as (15 cases), (13 cases), (8 cases), and (7 cases). 101 strains of 129 positive samples were identified as type A by sequencing. The annual epidemic pattern of in Beijing, is unimodal, and the epidemic season generally appears from March to July. The seasonal characteristics of in Beijing can be used for the differential diagnosis of from other respiratory pathogens. is most common in people aged 5-44 years, and the primary genotype is type A. People aged 10-44 years old suffer the highest incidence. If the nucleic acid positive rate of exceeds 0.30% for two consecutive months, the high prevalence period of can be preliminarily expected. infection has a higher probability of progressing to severe pneumonia from general pneumonia.