| BackgroundAt present,one of the most serious risks and challenges facing biosafety is respiratory infectious disease.Severe acute respiratory infection(SARI)is one of the most common causes of death caused by serious respiratory diseases or other system diseases.Indoor environment is the main place for the spread of respiratory infectious diseases,especially in public places with high density of people and relatively crowded like rail transit system.Respiratory syncytial virus(RSV)is a common cause of morbidity and mortality of lower respiratory tract infection.Moreover,there is no effective vaccine for RSV in clinic,which has caused a large medical burden.Therefore,based on the monitoring of common respiratory pathogens in Guangzhou,we have chosen to focus on the transmission characteristics of RSV among the affected populationObjective1.The virus air samples and contact surface smear samples of two representative subway lines 1 and 3 in Guangzhou from 2019 to 2022 were monitored by experimental methods for a variety of common respiratory pathogens,and analyze the spatial and temporal distribution characteristics of respiratory pathogens such as RSV in urban rail transit systems,and investigate whether there is a correlation between RSV general population monitoring and epidemic characteristics among the affected population;2.The nasopharynx swab samples from two sentinel hospitals in Guangzhou from 2019 to 2022 were tested for RSV and identified by typing,and the epidemiological information such as epidemic situation,time,region,population distribution were analyzed in detail.At the same time,the genome was sequenced to analyze the genetic evolution characteristics of RSV,providing a basis for the prevention and control of RSV infection and the prevention of outbreaks.Method1.Monitoring of common respiratory pathogens in Guangzhou rail transit system from 2019 to 2022The virus was sampled and analyzed at the selected two subway stations for 3 years.Draw a pathogen spectrum of common respiratory pathogens in the rail transit system,analyze the differences in virus concentration between sampling points,different time periods of human flow density,and different epidemic seasons,and obtain the distribution pattern and transmission characteristics of common respiratory pathogens in the subway.2.Epidemic and genetic characteristics of respiratory syncytial virus in hospitalized patients with fever and pneumonia in Guangzhou from 2019 to 2022Two sentinel hospitals in Guangzhou collected nasopharyngeal swabs from hospitalized patients with acute respiratory infection as samples.Luminex respiratory multi-pathogen detection technology was used to detect and type RSV in samples,and epidemiological information such as epidemic situation,time,area,population distribution,etc.were analyzed.Conduct virus isolation and culture on the positive samples of RSV,sequence the whole genome of the successfully isolated and cultured RSV strains,and analyze the genetic characteristics of RSV in combination with the laboratory’s early monitoring results.Results1.From 2019 to 2022,a total of 2679 subway air samples and environmental smear swab samples were collected for subway monitoring,including 2250 air samples and 429 environmental smear swab samples.The results of respiratory multi pathogen testing showed a total positive rate of 32.69%(879/2679),with a positive rate of 31.16%(701/2250)for air samples and 41.49%(178/429)for environmental swab samples.The positive rates in different years were 34.97%(134/383),36.55%(227/621),30.12%(244/810),and 28.39%(274/865),respectively.2.A total of 978 nasopharyngeal swab samples were collected for fever and pneumonia monitoring from 2019 to 2022.The overall positive rate of RSV was 5.52%(54 cases),including 2019(3.13%,10/319),2020(14.78%,30/203),2021(4.08%,10/245),and 2022(1.90%,4/211).The highest detection rate of RSV in children under 3 years old is 8.20%(47/573).In 2019 and 2021,subtypes A and B coexisted.In 2020,subtypes B(25/30)were predominant,while in 2022,subtypes A(4/4)were predominant.Conclusion1.From 2019 to 2022,the positive rate of respiratory pathogens in Guangzhou’s subway system showed a basic downward trend,indicating that epidemic prevention measures such as restricting personnel mobility and wearing masks can greatly suppress the spread of respiratory pathogens.However,the positive rate of respiratory syncytial virus is increasing against the trend,which requires special attention.It is recommended to strengthen household ventilation and personal protection for family members;2.Pathogens are effectively diluted during further transmission in the subway,especially to nearby populations;By selecting appropriate ventilation parameters,the risk of respiratory pathogen infection in the subway can be minimized to the greatest extent;Monitoring the respiratory syncytial virus in the subway cannot accurately reflect and predict the situation of the affected population.3.RSV is a common respiratory virus prevalent in Guangzhou,and children under 3 years old are the main population infected with RSV.RSV infection is prevalent every other year,and type A and type B are alternately prevalent,and anti seasonal prevalence has emerged after the COVID-19.This indicates that the COVID-19 has a certain impact on the transmission of RSV,which may be caused by the COVID-19 virus itself or the daily behavior changes brought about by epidemic prevention measures. |
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