The Study Of Natural Focus Diseases Among Part Of Rodents And People In Zengjiang River Area

BackgroundThere are many species of rodents in the world,including rabbit,rodent and insectivora,with more than 2000 species belonging to 35 families,accounting for nearly half of the mammal.Rodents have a strong adaptability that they can live all over the world.Rodents are hosts for a variety of natural focus diseases(NFD)and they have many opportunities to contact with human beings.So,rodents could expand the spread of NFD and cause human health and public health problems.At present,there are nearly 90 kinds of NFD that can be transmitted by rodents and cause human infection.NFD include Bartonella disease caused by bartonella,leptospirosis caused by leptospira,Lyme disease caused by borrelia burgdorferi,tsutsugamushi disease caused by oriental tsutsugamushi(Ot.),hemorrhagic fever with renal syndrome and pulmonary syndrome caused by hantavirus,Severe fever with thrombocytopenia syndrome(SFTS)caused by severe fever with thrombocytopenia syndrome virus,Ehrlichiosis caused by ehrlichia and endemic typhus caused by rickettsia mooseri.Zengjiang is in the east of Guangzhou city,Guangdong province,with a dense population and suitable climate.Many kinds of rodenttransmitted NFD have been reported in the surrounding areas,but the species and density of local rodents were not understood clearly.It was not clear if there were pathogens related to NFD in rodents,and the past infections of related pathogens in the population were rarely reported.Therefore,it is necessary to carry out an investigation of NFD,which can provide a scientific basis for the prevention and control of local NFD.Objectives1.To understand the species,distribution and density of rodents along the Zengjiang and obtain the infection of pathogens related to NFD in rodents.2.To understand the past infection of NFD related pathogens in local healthy population.3.To obtain the sequence and phylogenetic analysis the pathogen,which was the most common in rodents and people.MethodsThe investigation was carried out in Zengjiang sub-district(Shuidong Village,Xiayu Village Jiaoshiling Forest Park),Xiaolou Town(Jiangao Village),Zhengguo Town(Huangcaotan Village)where were near the area of Zengjiang(Zengcheng District).This investigation used cage-trap to captured rodents and collected serums of local healthy people.Descriptive analysis was conducted on characteristics of rodents and healthy people.RT-qPCR was used to detect the infection of NFD pathogens in rodents,ELISA was used to detect the IgG antibody in the serum of local healthy people,sequencing technique was used to phylogenetic analysis of positive samples.Results1.Rodents surveillanceA total of 69 rodents were captured in this study,33.33%were females,66.67%were males,and the ratio of male to female was 2:1.According to morphological identification,2 species of rodents were captured in this study with a total density of rodents was 13.29%and constituent ratio of Suncus murinus and Rattus norvegicus were 72.46%and 27.54%,respectively.The density was different in those survey sites(P<0.05).2.Detection of pathogens in rodentsA total of 32 rodents were detected NFD pathogens(Bartonella,Leptospira,Borrelia burgdorferi,Oriental tsutsugamushi,Hantavirus)with a total infection rate 46.38%.The infection rates of Bartonella,Leptospira,Borrelia burgdorferi,Oriental tsutsugamushi and Hantavirus were 28.99%,15.94%,2.90%,8.70%and 5.80%,respectively.Rickettsia mooseri,Severe fever with thrombocytopenia syndrome virus and Ehrlichia were not detected in this study.In addition,there were two and three pathogens co-infection in Rattus norvegicus,including:Bartonella+Leptospira+Borrelia burgdorferi,Bartonella+Leptospira+Hantavirus,Bartonella+Oriental tsutsugamushi,Bartonella+Leptospira,Leptospira+Hantavirus,Leptospira+Oriental tsutsugamushi,Oriental tsutsugamushi+Hantavirus with a total compound infection rate was 15.94%.3.Serological examination of healthy peopleA total of 90 serums of were detected.This study found IgG positive for Bartonella,Leptospira,B.burgdorferi,Ot and Hantavirus in local healthy people with positive rates were 12.22%,13.33%,12.22%,7.78%and 3.33%,respectively.4.Sequence and phylogenetic tree analysisThis study found B.elizabethae,B.grahamii,B.queenslandensis and other unclear species,those sequences were based on the gene of gltA,ftsZ and 16SrRNA.Conclusions1.The local dominant rodent species were Rattus norvegicus and Suncus murinus,those rodents could spread a variety of NFD.2.This study found Bartonella,Leptospira,B.burgdorferi,Ot.and Hantavirus in rodents and there was compound infection situation in Rattus norvegicus.3.This study found past infections of Bartonella,Leptospira,B.burgdorferi,Ot and Hantavirus in the healthy population along the Zengjiang river area.4.The genotypes of pathogens obtained in Zengjiang river area included B.grahamii,B.elizabethae,B.queenslandensis and other unclear species of Bartonella,which were harmful to humans.