Etiology And Epidemic Characteristics Of Respiratory Viruses In Urumqi From 2017 To 2019

Objective:To analyze the etiology and patient information of respiratory viruses in Urumqi from 2017 to 2019,in order to grasp the epidemic characteristics,At the same time,the molecular epidemiology of influenza A H3N2 virus gene in Urumqi was analyzed to understand its evolutionary characteristics,and to provide favorable theoretical basis for the rational allocation of health resources and scientific formulation of prevention and treatment plan in Urumqi.Methods:1)In this study,the combination of disease monitoring technology and field epidemiological survey technology was used to study.According to the relevant requirements of national influenza surveillance technical guidelines(2017 Edition),the upper respiratory tract samples(throat swab samples)were collected,transported and tested.Methods Retrospective case collection method was used to collect the basic information of influenza like cases in two sentinel hospitals in Urumqi from January 1,2017 to December 31,2019.2)Objective to isolate and purify H3N2 subtype influenza virus from Urumqi.After obtaining the virus strain,gene amplification and sequencing were performed to analyze its molecular characteristics.Results:1)Epidemiological characteristics:(1)population distribution: the overall detection rate of respiratory pathogens decreased with age,and the detection rate of influenza virus was the highest in children aged 13-15.(2)Time distribution: in 2017-2019,the detection rate of respiratory pathogens was relatively stable,and there was no obvious upward trend,among which the detection rate of influenza virus had obvious seasonal characteristics,which was higher in winter and spring.2)Pathogenic characteristics: PCR results showed that the total pathogen detection rate was 52.5%,of which influenza virus detection rate was the highest(33.82%),the dominant type was seasonal H3.In addition to influenza virus,the detection rate of syncytial virus was high(16.49%),followed by rhinovirus(6.70%),and Mycoplasma pneumoniae(1.32%).3)Analysis of gene characteristics:The results showed that the homology of each gene fragment was 99.72%-99.99% among isolates,and 97.58%-98.75% between isolates and reference sequence;In addition,the mutation of HA fragment was as follows: T144A?R158G?K169S?E78G?N187K?Q189K ? Q277R;The variation of Na fragment was as follows: N329 S ? E344 K.Conclusion: 1)H3 is the main influenza virus in Urumqi;The detection rate of syncytial virus was higher in other respiratory pathogens,followed by adenovirus.The positive results of influenza virus detection have obvious seasonality,while the other pathogens have no obvious seasonality,and occur sporadically in all seasons of the year.In addition to influenza virus,the detection rate of syncytial virus is the highest among the respiratory pathogens,which indicates that it is of great significance to strengthen the pathogen research of respiratory infection symptoms besides influenza virus for the prevention and control of respiratory diseases.2)The HA and NA antigenic sites of the isolates were changed to some extent,but the drug resistance sites were not changed.In the future,we should continue to strengthen the etiological monitoring of influenza virus,track the replacement of key amino acid sites in time,and provide theoretical basis for scientific prevention and control.