What is avian influenza?

　　Avian influenza, referred to as avian influenza for short, is an infectious disease of poultry caused by influenza A virus, which mainly occurs in chickens, ducks, geese and pigeons. Among them, highly pathogenic avian influenza is classified as a class A animal disease by the World Organization for Animal Health because of its rapid spread and great harm, and it is classified as a class of animal disease in China.

　　How does bird flu spread?

　　The source of infection of avian influenza is mainly chickens and ducks, especially infected.H5N1In chickens with virus, the virus can spread through digestive tract, respiratory tract, skin injury and conjunctiva. Under natural conditions, the avian influenza virus existing in oral cavity and feces has great resistance due to the protection of organic matter, especially in cool, humid and mild conditions, which can survive for a long time, and human beings are directly exposed to it.H5N1Virus-infected poultry and their feces or direct contactH5N1The virus will be infected. In addition, the disease can also be transmitted through droplets and contact with respiratory secretions.

　　Are migratory birds the source of avian influenza infection?

　　It is not clear whether this conclusion is established or not. At the beginning, the West Nile virus popular in the United States also suspected that the "culprit" was migratory birds. The key point is, migratory birds are regional, will it cause transnational or even transcontinental spread? The whole situation has yet to be investigated in depth, and the medical profession is currently waiting for the exact result. Once confirmed, I believe that the relevant state departments will take emergency measures.

　　Confirmation of epidemic situation

　　Generally, there are four steps: first, after the outbreak of avian influenza, experts conduct on-site diagnosis and epidemiological investigation, which can be initially diagnosed as a suspected case of highly pathogenic avian influenza. The second is to identify the hemagglutinin subtype of the virus by serological method. Third, the virus was isolated and identified by the National Avian Influenza Reference Laboratory, and finally the virus type was determined. Fourth, the Ministry of Agriculture finally confirmed or ruled out the epidemic situation of highly pathogenic avian influenza according to the diagnosis results of the National Avian Influenza Reference Laboratory.

　　Why does bird flu spread rapidly?

　　There are many raw chicken markets in the border areas of southern Asian countries. When raw chickens are traded across borders, there is no virus quarantine link. It is very likely that bird flu will spread rapidly to other countries through infected raw chickens or chicken droppings on the shoes of raw chicken traders. Some countries lack monitoring of chicken farms and fail to grasp the epidemic situation of avian influenza and take preventive measures as early as possible.

　　Avian influenza can be prevented and controlled.

　　The prevention and control of avian influenza has a history of more than 100 years, and all countries in the world have accumulated rich experience. From the prevention and control experience of various countries, highly pathogenic avian influenza in poultry can be completely prevented; Once an epidemic occurs, as long as measures such as tight blockade, thorough culling, disinfection and harmless treatment are taken in a timely, decisive and resolute manner, it can also be effectively controlled.

　　How to kill avian influenza virus

　　The tolerance of avian influenza virus is relatively poor. Influenza virus is sensitive to organic solvents such as ether, chloroform and acetone. Commonly used disinfectants, such as formalin, oxidant, dilute acid, sodium deoxycholate, hydroxylamine, sodium dodecyl sulfate and ammonium ions, halogen compounds (such as bleaching powder and iodine agent) and heavy metal ions, can quickly destroy its infectivity.

　　In addition, influenza virus is also sensitive to heat. When heated at 56 degrees Celsius for 30 minutes, 60 degrees Celsius for 10 minutes, and 65-70 degrees Celsius for several minutes, influenza virus loses its activity. However, the virus has a strong resistance to low temperature, and can remain active for more than one year under the protection of glycerol.

　　 The virus can also be killed in direct sunlight for 40-48 hours, and its infectivity can be quickly destroyed if it is directly irradiated with ultraviolet rays. Direct ultraviolet rays can destroy its infectivity, hemagglutinin activity and neuraminidase activity in turn.

　　Symptoms of avian influenza

　　The incubation period of human suffering from avian influenza is generally less than 7 days. In the early stage, the main symptoms are fever, runny nose, stuffy nose, cough, sore throat, headache and general malaise. Some patients may have digestive tract symptoms such as nausea, abdominal pain, diarrhea, watery stool, etc. Some patients may have conjunctivitis, and their body temperature is mostly above 39℃. Some patients’ chest X-rays will also show unilateral or bilateral pneumonia, and a few patients will have pleural effusion.

　　Most patients are cured well, the course of disease is short, and they recover quickly without sequelae, but a few patients, especially those who are older and treated too late, will quickly develop into various complications such as progressive pneumonia, acute respiratory distress syndrome, pulmonary hemorrhage, pleural effusion, pancytopenia, renal failure, septic shock and Reye syndrome and die.

　　High-risk groups susceptible to avian influenza

　　Four groups of people, such as raising, transporting, slaughtering and selling poultry, are high-risk groups of bird flu. In addition, bird flu is particularly easy to attack children, the elderly and people with weak constitution.

　　Can poultry meat and eggs still be eaten?

　　After the poultry meat and eggs are cooked thoroughly, the possibility of virus transmission is small. However, if it is a sick bird or carries the virus and is not cooked thoroughly, the virus is likely to enter the human body.

　　At present, China’s quarantine department has taken emergency preventive measures, and poultry in the regular market can basically be safely eaten. The key is to cook thoroughly. If you eat poultry that have not been quarantined or come from the outbreak area, the risk of infection is not ruled out.

　　Can you be infected by wearing down jackets and covering down ducks?

　　The person in charge of the Shanghai Veterinary Health Supervision Institute said that wearing down jackets, covering down quilts and related products will definitely not infect bird flu. Because down products are usually treated by disinfection, high temperature and other physical and chemical links, the possibility of virus survival is very small and it is unlikely to cause harm to people’s health.

　　People: Stay away from bird flu at four o’clock.

　　Suggestion 1: Don’t travel in epidemic areas.

　　Tourists should avoid going to areas where bird flu has broken out. Because at present, the source of avian influenza virus has not been found, and we don’t know the real transmission route of the virus and whether it will be transmitted from livestock to humans or from person to person.

　　Recommendation 2: Don’t contact live birds.

　　If you must go to an area where bird flu is prevalent, you must remember that livestock manure is probably one of the ways of bird flu transmission. Remember to wash your hands thoroughly with hand sanitizer and water after touching livestock. People, especially children, should avoid contact with live birds.

　　Recommendation 3: Pay attention to disease prevention.

　　Usually, we should strengthen physical exercise and rest more to avoid excessive fatigue; When an epidemic situation is discovered, contact with poultry should be avoided as far as possible, raw food and cooked food should be separated in the kitchen, raw food or semi-cooked food, especially uncooked animal blood products, should be thoroughly cooked for chicken, eggs and other foods; Keep the indoor air circulating. If there is air conditioning equipment, clean the dust screen frequently, and try to avoid going to places where the air is not circulating. Pay attention to personal hygiene and wash your hands in the right way; Cover your mouth and nose when sneezing or coughing; Keep indoor furniture clean and avoid using carpets that are difficult to clean.

　　Recommendation 4: Pay attention to high-temperature antivirus.

　　In addition, avian influenza virus is sensitive to organic solvents such as ether, chloroform and acetone, high temperature and ultraviolet rays. Heating at 56℃ for 30 minutes, heating at 60℃ for 10 minutes, heating at 70℃ for several minutes, direct sunlight for 40 to 48 hours and using common disinfectants can kill avian influenza virus.

Government: Eight Measures to Prevent and Control Avian Influenza

　　Wen Jiabao, Prime Minister of the State Council, presided over the 37th executive meeting of the State Council on January 29th to study and deploy the prevention and control of highly pathogenic avian influenza. The meeting decided that the prevention and control of highly pathogenic avian influenza should focus on eight measures.

　　·In areas where the epidemic situation has been discovered, it is necessary to timely and accurately announce the epidemic situation in accordance with the prescribed procedures, resolutely cull, thoroughly disinfect, strictly isolate, and enforce immunization in accordance with the requirements of epidemic prevention work, and resolutely prevent the spread of the epidemic situation.

　　·In areas where no epidemic situation has been found, it is necessary to do a good job in epidemic prevention and improve the emergency plan for the epidemic situation. It is necessary to focus on the epidemic prevention work in key areas, large-scale farms and large-scale breeding professionals, strengthen epidemic monitoring, and take effective measures to prevent the outbreak.

　　·Establish a mechanism to deal with sudden major animal epidemics. We will step up the establishment and improvement of epidemic monitoring and quarantine networks, and strengthen the construction of animal epidemic prevention infrastructure and grassroots epidemic prevention teams.

　　·Implement epidemic prevention funds and clarify compensation policies. Reasonable compensation should be given for the loss of culling poultry in areas where highly pathogenic avian influenza occurs, and compulsory immunization of poultry should be implemented free of charge, so that the people can have no worries. The funds required for culling and compulsory immunization according to regulations shall be shared by the central and local governments.

　　·Strengthen scientific research. It is necessary to organize scientific and technological research on highly pathogenic avian influenza virus and its prevention and control, rationally arrange the production and storage of highly pathogenic avian influenza vaccine, and actively carry out international exchanges and cooperation in the prevention and control of highly pathogenic avian influenza.

　　·Strengthen the quarantine of import and export poultry and their products to prevent the spread of the epidemic. Severely crack down on smuggling of poultry products. Strengthen the management of poultry market and the detection of epidemic diseases.

　　·Do a good job in the propaganda of popular science knowledge about the prevention and treatment of highly pathogenic avian influenza, so that the broad masses can understand the characteristics and prevention knowledge of the spread of highly pathogenic avian influenza.

　　·Resolutely prevent highly pathogenic avian influenza from infecting people. At present, we should focus on medical monitoring and prevention of epidemic areas and high-risk groups.

Q&A experts: Wu Jiang, Director of Infectious Diseases and Endemic Diseases Control Institute of Beijing CDC; Jia Youling, Chief Animal Husbandry Officer of the Ministry of Agriculture; Zhou Jiao, Chairman of Poultry Branch of China Animal Husbandry and Veterinary Society; Professor Pan Xiaozhang, Associate Professor Lu Hongzhou, Chief Physician Shi Guangfeng, and Professor Xu Hongfa, Ph.D. Supervisor of School of Life Sciences of East China Normal University.

Design and production, graphic editing: Yu Xi