| Avian Influenza(Avian Influenza)is a syndrome caused by avian influenza virus in birds.It can be classified into highly pathogenic and low-pathogenic avian influenza viruses according to their fatalities.In recent years,the highly pathogenic avian influenza virus has attracted widespread attention due to its cross-species transmission and high lethality.The H5 subtype is a highly pathogenic subtype that was discovered earlier and widely distributed.The role of migratory birds has been questioned for the long-distance transmission of bird flu virus.To study the outbreak,spread and future development trend of the H5 subtype HPAI virus,and it is of great significance to prevent and control the wild bird epidemic.Studying the outbreak,spread,and future development trend of the H5 subtype HPAI virus is a great significance for the prevention and control of wild bird outbreaks.This study first conducted a preliminary statistical analysis of the outbreak and evolution of the highly pathogenic avian influenza virus H5N1 and H5N8 subtypes in recent years.In addition,the MaxEnt model was used to predict the current and future spatial suitability distribution of highly pathogenic avian influenza strains of H5N1 and H5N8 subtypes,respectively.Finally,the present situation of the disease stress in the nature reserves of wild birds in China is analyzed and discussed.The research results are as follows:1.There have been two major outbreaks of highly pathogenic avian influenza H5N1 worldwide,around 2006 and 2016,respectively.The number of outbreaks has decreased in recent years.The H5N8 avian influenza virus erupted mainly between 2016 and 2017,the number of outbreaks has an increasing trend.Asia is the center of two avian influenza virus outbreaks.2.The prediction model shows that highly pathogenic avian influenza H5N1 subtype strains are mainly distributed in Europe,Germany,France,the Czech Republic to the Caspian Sea area,Asia,Bangladesh,Nepal,Vietnam,Japan and China’s Guangdong and Guangxi coastal area.The highly adapted regions of H5N8 subtype avian influenza strains are mainly distributed in Germany and Czech Republic in Europe,while Sichuan,Guizhou and other places in China and the eastern United States,Japan,and Korean Peninsula are currently in low-level suitability regions.3.In the prediction of H5N1,the dependence of predicted suitability shows a peak when the average temperature of the year is 10℃,the highest temperature of the warmest month is 25℃,the lowest temperature of the coldest month is-5℃,the annual temperature range difference is 23℃,solar radiation is 1400 kJ·m-2·day-1,the ultraviolet intensity is 3.0Kpa,the precipitation in the driest season is about 200mm,or the wind speed is 2m/s.4.In the prediction of H5N8,the dependence of predicted suitability shows a peak when the average temperature of the year is 11℃,the highest temperature of the warmest month is about 22℃,the lowest temperature of the coldest month is-5℃,the precipitation in the wettest month is about 150mm,the driest month is 50mm,the solar radiant energy is about 12500 kJ·m-2·day-1,the atmospheric water vapor pressure is 0.8 KPa,or the wind speed about 4m/s.5.The results of the prediction model show that the addition of poultry data is likely to lead to misjudgment of the level of disease threat to wild birds.6.Different carbon emission conditions in the future will affect the suitability distribution areas and attribute values of the two subtype strains.The human footprint also has a great influence on the distribution of the two subtype viruses.7.The current hot spot of wild bird death caused by the H5N1 strain is concentrated in Qinghai and Tibet,and the development trend of H5N8 in China presents a shift from west to east.The study of the values of the suitability distribution area attributes shows that the 77 bird sanctuaries in our study may currently be under pressure from both diseases. |
