Risk Ananlysis On Avian Influenza Viruses Circulation In Wild Waterfowl In Jiangsu Provience

Avian influenza is a kind of disese with acute and high infectious spread by contact or respiratory,caused by the avian influenza virus.Which some showed chronic infection without obvious symptoms,while some showed acute infection and can be caused100%mortality. The research data collected shows that:wild waterfowl(inparticular,Anseriformes and Charadriiformes) are the "nature reservoir"of avian influenza virus, all HA and NA subtypes were isolated from wild waterfowls,but theirselves were of no disease.Meanwhile avian influenza viruses are highly species-specific, usually they can only survive in some certain species of animals, and rarely cause infection in other species,but since1997the breakout of the Hong Kong avian influenza to broke though the species barrier and caused the phenomenon of human infection resulting in death.The avian influenza virus particular HPAI H5N1subtype have draw the the world’s attention.In view of the above reasons, bird flu source-wild waterfowl are paid more attention by human. Under the leadership of World Health Organization (WHO), World Organization for Animal Health (OIE), Food and Agriculture Organization (FAO), a worldwide monitoring system had been established by many countries and regions,so as to monitoring of the spread of avian flu timely, dynamicly, and efficiently,and protect the people’s health in the world from bird flu.The experiment was conducted by epidemiological investigation of bird flu on eight kinds of wintering ducks in Jiangsu Hongze Lake Wetland Nature Reserve,and the World Trade Organization (WTO) and the World Organization for Animal Health (OIE) in the "Animals and Plants Quarantine and Health Measures "(SPS Agreement) and the" International Animal Health Code "and other important laws documentation requirement for the theoretical basis,based on the reference the basic framework on the animal disease risk analysis in import and export of OIE,as well as some basic available datas collected from OIE, WHO and other relevant organizations or some publicly information. Risk analysis on avian influenza virus circulation in wild waterfowls in Hongze Lake in Jiangsu Province was conducted and given out the risks management recommendations. The study will now be summarized as follows:In November2008to February2009period, a total of160cloacal swabs were collected from8kinds of wild waterfowls which wintered in Hongze, Xuyi Wetland Nature Reserve, Jiangsu Province.The cloacal swabs were inoculated10-day-old SPF chicken embryo after treatment. Hemagglutination test and Newcastle disease virus Hemagglutination Inhibition test were carried out,10virus with hemagglutination activity, of which eight viruses identified as avian influenza virus, the virus isolation rate was5%(8/160),2strains Newcastle disease virus, the virus isolation rate was1.25%(2/160).The primers of NS, HA, NA gene were designed according to the designation of influenza virus universal primers by Hoffman et al (2001),3strains H11subtypes,1strain H6N8subtype were identified though Reverse-transplate-PCR amplification of HA and NA gene, then with T/A colned and sequenced by Intrivigen,the sequence were sequence analysis by the NCBI.What a conclusion can draw based on past data is that there are the existence of H11,H6subtype and N8subtype,or their combilations H11,H6N8at least, indicating that the the prevalence bird flu virus of increasingly complex and showing the coexistence of multiple subtypes situation in recent years, in which H11was the dominant subtype and N8subtype was the newly discovered subtype,so in order to prevent the different subtypes of wetlands resulting from the reorganization of a new strain of the need to strengthen surveillance and defense. The sequence alignment analysis shows that, H11, and N8subtypes isolated form Jiangsu are highly homologous to the sequences from reported from Hokkaido, Osaka, Australia, Korea in recent years,so it can be deduced that wild waterfowl with these pathogens may have some kinds of contac or other relations.Laboratory reseach data in recent years was analysised comprehensively and based on the reference the basic framework on the animal disease risk analysis in import and export of OIE,as well as some basic available datas collected from OIE, WHO and other relevant organizations or some publicly information. Risk analysis on avian influenza viruses circulation in wild waterfowl in Hongze Lake in Jiangsu Province was conducted.The results show that wild waterfowls within the wetlands are of great risk in spreading avian influenza,but the risk can be reduced to within appropriate level of protection with some measures were taken on some condition,so as to paly a certain role in forecast of bird flu in wetland.