Analysis On The Effect Of Indoor Microorganism Control In Hospital And Study On Characteristics Of Microbial Community In General Hospital

There are pathogenic and non-pathogenic microorganisms in the indoor air of the hospital,which can cause infection in the hospital by entering the human body in the form of microbial aerosol.Therefore,it is very important to purify and disinfect the hospital air.At present,traditional air purification and disinfection methods have certain limitations,and some cannot be used when there are people in the environment.Enzyme sterilization air purification equipment combines enzyme sterilization technology with filter material to achieve dynamic air purification and disinfection.There are many kinds of bacteria and fungi in hospital air,which have different effects on human health,therefore,the analysis of indoor air microbial concentration level in hospital rooms with purification equipment can have an overall understanding of the control effect of purification equipment.Meanwhile,due to the diversity of indoor microbial community structure,its composition and proportion are of great significance to control hospital microbial pollution,prevent diseases and avoid hospital infection.In this paper,the effect of microbial control in typical functional areas with air purification and disinfection equipment in four hospitals of three climate zones was tested and evaluated by sedimentation method combined with laboratory culture analysis.Meanwhile,the environmental temperature,humidity and PM_2.5 were analyzed.In addition,the impact sampling method was used to test and analyze the aerosol concentration and particle size distribution in waiting room and outpatient Hall of different hospitals without air purification equipment.High throughput sequencing technology was used to analyze the characteristics of indoor microbial community in typical rooms of the general hospital without air purification equipment.The main conclusions are as follows:（1）In the purified environment,the indoor bacterial concentration in the class II environment of different hospitals was（10～157）cfu/m³,and the indoor fungal concentration was（10～209）cfu/m³;The concentrations of bacteria and fungi in class III and IV rooms were（94～314）cfu/m³ and（126～424）cfu/m³ respectively,which met the limits of class II,III and IV environmental standards stipulated by the hospital.The concentration of PM_2.5 in different rooms of different hospitals was less than 35μg/m³.（2）According to the research,the test results of single room purifier were tested.When an air purifier with a circulating air volume of 200 m³/h is set in the room,the equation for calculating the equilibrium concentration of indoor pollutants removed by the air purifier is established.The concentration of indoor bacteria can reach the class II environmental standard of the hospital,and the sterilization rate can reach more than 92%;The sterilization rate of air in 36m³ room can reach more than 91%after one hour.（3）The concentration of fungal aerosol was higher than that of bacteria in waiting room and outpatient Hall of different hospitals,The concentration of bacteria ranged from（209±26）cfu/m³to（704±29）cfu/m³,the concentration of fungi ranged from（343±44）cfu/m³ to（838±10）cfu/m³.The average concentration of fungi is higher than that of bacteria.（4）The particle size distribution of bacteria and fungi in the waiting room and outpatient Hall of different hospitals was different,mainly in the range of 1.1～4.7μm,the median diameter of bacteria ranged from 2.08～2.86μm,the median diameter of outdoor bacteria was larger than that of indoor,and the median diameter of fungi ranged from 1.70～2.85μm.（5）In autumn,cities in different climate regions,the outdoor microbial concentration of city B was the highest,and that of City C was the lowest.The range of bacterial concentration was（231±26）cfu/m³～（674±30）cfu/m³,and the range of fungal concentration was（343±44）cfu/m³～（806±10）cfu/m³.The median diameter of bacteria ranged from 2.64～3.19μm,and that of fungi ranged from 2.37～2.47μm.（6）Bacteroidetes,Firmicutes and Proteobacteria were the dominant bacteria in surgical ward,dental clinic and outpatient hall of the general hospital,accounting for 53.34%,23.99%and 15.77%respectively;At the genus level,Prevotella,Bacteroides and lactobacillus were the dominant genera.（7）Basidiomycota and Ascomycota were the dominant fungal in surgical ward,dental clinic and outpatient hall of the general hospital,accounting for 71.81%and 21.54%respectively.At the genus level,Aspergillus was the dominant bacteria in surgical ward,and Schizophyllum was the dominant bacteria in dental clinic and outpatient hall.