Some questions about bird flu

What is avian influenza

Avian influenza is a syndrome of symptoms ranging from respiratory disease to severe septicemia in poultry and wild birds caused by type A influenza virus. It currently occurs in many countries and regions around the world, causing huge economic losses to the poultry industry. This kind of avian influenza virus mainly causes systemic or respiratory diseases in poultry. Poultry such as chickens, turkeys, ducks and quails, as well as wild birds, waterfowl, seabirds, etc. can be infected. The incidence ranges from acute septicemia to asymptomatic death. The virus transmission is extremely diverse, mainly depending on the resistance of the disease carrier and the type and virulence of the virus it infects.

The avian influenza virus is different from the SARS virus. So far, the avian influenza virus can only be transmitted to humans through birds, but cannot be transmitted to humans through humans. The avian influenza virus H5N1 that infects humans is a mutated new virus, not the H5N2 that has been circulating in chickens, ducks and birds for decades. There is no need to talk about the discoloration of bird flu. At present, it has not been found that eating chickens causes avian influenza H5N1 to be transmitted to humans. It is all close contact with chickens, and infection may be caused by direct inhalation of the virus or entry into mucous membranes.

The main symptoms of avian influenza

High fever, cough, runny nose, myalgia, etc. Most avian influenza patients are accompanied by severe pneumonia, and in severe cases, heart and kidney failure lead to death.

Multiple transmission routes

It can be transmitted through various routes such as the digestive tract, respiratory tract, skin lesions and conjunctiva.

The mortality rate is higher than that of SARS

In 1997, Hong Kong H5N1 avian influenza virus infection caused 12 cases, of which 6 died; Vietnam has confirmed 15 cases since October last year Humans have been infected with avian influenza and 13 people have died. According to statistics from the World Health Organization, more than 8,000 people in more than 30 countries and regions around the world were infected with the SARS virus last year, and more than 700 of them died, with a mortality rate of about 9%.

What is a new type of influenza?

Xinhuanet, Tokyo, February 2 (Reporter He Degong) Since December last year, highly pathogenic avian influenza has spread rapidly in Asian countries, and human deaths due to H5N1 virus infection have also occurred in Vietnam and Thailand. On the 1st, the World Health Organization announced that there were suspected cases of human-to-human transmission of avian influenza in Vietnam. Japanese experts believe that a new type of influenza may appear, and humans should remain highly vigilant about this.

So, what is the new type of influenza? In short, it is a new influenza that can spread quickly from person to person and can cause great harm to humans when humans are not fully prepared. From the current point of view, people are most worried that the new influenza may be caused by a sudden mutation of the circulating H5N1 virus gene.

The H5N1 virus is a virulent virus. According to Japanese virus expert Masato Tashiro, judging from the symptoms of patients infected with this highly pathogenic avian influenza, it can no longer be said to be influenza. 4 The autopsy results of Vietnamese patients who died of avian influenza showed that in addition to severe disorders in the lungs and digestive organs, they were also accompanied by symptoms of multiple organ dysfunction, similar to Ebola hemorrhagic fever. In terms of mortality, 18 people in Hong Kong were infected with avian influenza caused by the H5N1 virus in 1997, and 6 of them died, while the mortality rate of general influenza is only 0.01%.

So far, patients with avian influenza caused by the H5N1 virus are mostly transmitted from chickens to humans due to contact with chickens. The World Health Organization has announced suspected cases of human-to-human avian influenza transmission, and the results are still unclear. Awaiting further confirmation. Generally speaking, it is difficult for avian influenza viruses to cross species boundaries. Due to the different cell receptor structures of birds and humans, it is difficult for the virus to multiply in the body after humans are infected with avian influenza viruses. This is why the H5N1 virus is currently infective to humans. The reason for the weakness. However, once the H5N1 virus gene mutates and becomes a new type of influenza virus that is easily transmitted between people, it will cause great harm to humans.

Japanese experts believe that the H5N1 virus gene suddenly mutates and becomes a new type of influenza that harms humans mainly through two channels: First, pigs that can be infected with both human viruses and avian viruses are used as an intermediary. The avian virus and the human virus combine in pigs, and the virus genes suddenly mutate, and a new influenza virus that is easily transmissible appears in the population; 2. In the bodies of patients infected with avian influenza, the avian virus and the human virus combine, and the genes suddenly mutate , becoming an influenza virus that spreads easily among people.

Tashiro believes that if human infection with avian influenza recurs and cannot be effectively controlled, there is a high possibility of a new type of influenza.

Experts believe that there are three points to pay attention to when dealing with new influenza: First, patients with avian influenza and pigs infected with avian influenza must be monitored, and once new influenza is discovered, isolation measures must be taken immediately; second, new influenza must be stepped up. Vaccine development and production; 3. Reserve antiviral drugs. Only in this way can humans be prepared for any danger

Highly pathogenic avian influenza occurs most frequently in winter and spring

Xinhuanet, Beijing, February 2 (Reporters Yao Runfeng and Dong Jun ) According to the Office of the National Highly Pathogenic Avian Influenza Prevention and Control Headquarters, highly pathogenic avian influenza can occur throughout the year, but is more common in winter and spring. The main reasons are:

The impact of influenza viruses on Temperature is relatively sensitive. As the ambient temperature increases, the survival time of the virus shortens. In addition, the light intensity is relatively higher in summer and autumn, and ultraviolet rays in the sun have a strong killing effect on viruses.

The ventilation intensity of poultry houses in summer and autumn is much higher than that in winter and spring. Good ventilation can greatly reduce the number of viruses in the chicken house environment. Therefore, the chance and number of viruses to invade the chickens are significantly reduced, and infection The probability decreases. At the same time, good ventilation also reduces the irritation of bad gases to the chicken respiratory mucosa, which is of great significance in maintaining the resistance of the respiratory mucosa

The main clinical manifestations and epidemic characteristics of highly pathogenic avian influenza

Xinhuanet, Beijing, February 2 (Reporters Yao Runfeng and Dong Jun) According to the Office of the National Highly Pathogenic Avian Influenza Prevention and Control Headquarters, acute infection of avian influenza has no specific clinical symptoms and can be seen within a short period of time. Loss of appetite, sudden rise in body temperature, and severe depression, accompanied by a large number of deaths.

Highly pathogenic avian influenza is similar to ordinary avian influenza viruses and can be prevalent throughout the year, but it is more likely to be prevalent in winter and spring because avian influenza viruses are more resistant at low temperatures. Poultry of various breeds and ages can be infected with highly pathogenic avian influenza, which has an acute onset and rapid spread, and its fatality rate can reach 100%.

Avian influenza is the abbreviation of avian influenza. According to the different pathogenicity of avian influenza, avian influenza can be divided into highly pathogenic avian influenza, low pathogenic avian influenza and non-pathogenic avian influenza. The recent avian influenza caused by the H5N1 serotype at home and abroad is called highly pathogenic avian influenza, with high morbidity and mortality and great harm

The incubation period of highly pathogenic avian influenza ranges from hours to days. Up to 21 days

Xinhuanet, Beijing, February 2 (Reporters Yao Runfeng and Dong Jun) According to the Office of the National Highly Pathogenic Avian Influenza Prevention and Control Headquarters, the incubation period of highly pathogenic avian influenza ranges from several to hours to several days, up to 21 days. There are two ways of transmission of avian influenza: direct contact between sick birds and healthy birds and indirect contact with viral contaminants.

The length of the incubation period is affected by many factors, such as the virulence of the virus, the number of infections, the bird's resistance, age and breed, feeding and management conditions, nutritional status, environmental sanitation and availability. Regardless of the influence of stress conditions, highly pathogenic avian influenza has a short incubation period and high morbidity and mortality. There is a possibility of infection during the incubation period.

Avian influenza virus exists in the digestive tract, respiratory tract and poultry organ tissues of sick and infected birds. Therefore, the virus can be excreted from the body along with eye, nose, oral secretions and feces. Any objects contaminated by secretions, feces, and dead poultry carcasses containing avian viruses, such as feed, drinking water, chicken coops, air, cages, and feeding and management equipment, Transportation vehicles, insects, and various virus-carrying birds can all spread mechanically. Healthy poultry are infected through the respiratory tract and digestive tract, causing disease

What is a new type of influenza: Rapid transmission between people is extremely harmful

Xinhuanet, Tokyo, February 2 (Reporter He Degong ) Since December last year, highly pathogenic avian influenza has spread rapidly in Asian countries. There have also been cases of human death due to infection with the H5N1 virus in Vietnam and Thailand. On the 1st, the World Health Organization announced the emergence of human-to-human transmission in Vietnam. There are suspected cases of bird flu transmitted among people. Japanese experts believe that a new type of influenza may appear, and humans should remain highly vigilant against this.

So, what is the new type of influenza? In short, it is a new influenza that can spread quickly from person to person and can cause great harm to humans when humans are not fully prepared. From the current point of view, people are most worried that the new influenza may be caused by a sudden mutation of the circulating H5N1 virus gene.

The H5N1 virus is a virulent virus. According to Japanese virus expert Masato Tashiro, judging from the symptoms of patients infected with this highly pathogenic avian influenza, it can no longer be said to be influenza. 4 The autopsy results of Vietnamese patients who died of avian influenza showed that in addition to severe disorders in the lungs and digestive organs, they were also accompanied by symptoms of multiple organ dysfunction, similar to Ebola hemorrhagic fever. In terms of mortality, 18 people in Hong Kong were infected with avian influenza caused by the H5N1 virus in 1997, and 6 of them died, while the mortality rate of general influenza is only 0.01%. So far, most cases of avian influenza caused by the H5N1 virus are caused by contact with chickens and are transmitted from chickens to humans. The World Health Organization has announced suspected cases of human-to-human transmission of avian influenza, but the results have yet to be further confirmed. Generally speaking, it is difficult for avian influenza viruses to cross species boundaries. Due to the different cell receptor structures of birds and humans, it is difficult for the virus to multiply in the body after humans are infected with avian influenza viruses. This is why the H5N1 virus is currently infective to humans. The reason for the weakness. However, once the H5N1 virus gene mutates and becomes a new type of influenza virus that is easily transmitted between people, it will cause great harm to humans.

Japanese experts believe that the H5N1 virus gene suddenly mutates and becomes a new type of influenza that harms humans mainly through two channels: First, pigs that can be infected with both human viruses and avian viruses are used as an intermediary. The avian virus and the human virus combine in pigs, and the virus genes suddenly mutate, and a new influenza virus that is easily transmissible appears in the population; 2. In the bodies of patients infected with avian influenza, the avian virus and the human virus combine, and the genes suddenly mutate , becoming an influenza virus that spreads easily among people. Masato Tashiro believes that if human infection with avian influenza recurs and cannot be effectively controlled, there is a high possibility of a new type of influenza.

Experts believe that there are three points to pay attention to when dealing with new influenza: First, patients with avian influenza and pigs infected with avian influenza must be monitored, and once new influenza is discovered, isolation measures must be taken immediately; second, new influenza must be stepped up. Vaccine development and production; 3. Reserve antiviral drugs. Only in this way can humans be prepared for any dangers

What are the common symptoms of avian influenza?

Xinhuanet, Beijing, January 28 (Reporters Xu Jingyue and Zhang Xiaosong) The symptoms of avian influenza vary depending on the species of infected birds, age, gender, degree of concurrent infections, virus virulence and environmental factors, etc. , mainly manifested as abnormalities of the respiratory tract, digestive tract, reproductive system or nervous system.

Common symptoms include depressed chickens, reduced feed consumption, and weight loss; hens

have increased nesting ability and decreased egg production; mild to severe respiratory symptoms , including coughing, sneezing, and profuse tearing; edema of the head and face, neurological disorders, and diarrhea.

Any of these symptoms may occur alone or in different combinations. Sometimes disease outbreaks occur quickly and chickens are found dead without obvious symptoms.

In addition, the morbidity and mortality of avian influenza vary greatly, depending on the bird species and strain, as well as age, environment and concurrent infections. Generally, the morbidity and mortality are high and low. In highly pathogenic viral infections, morbidity and mortality can reach 100%.

The incubation period of avian influenza ranges from hours to days, and its length is related to the pathogenicity of the virus, the dose of the infecting virus, the route of infection and the breed of infected poultry

Indonesia The death toll from bird flu reached 43, surpassing Vietnam as the world's highest number

2006-8-9

The World Health Organization (WHO) confirmed on the 9th that a 16-year-old boy outside the Indonesian capital Jakarta Died due to infection with highly pathogenic avian influenza (H5N1). The number of deaths from bird flu in the country has increased to 43, surpassing Vietnam's 42 people and becoming the country with the highest number of deaths from bird flu in the world.

*** The same news agency reported that Vietnam has blocked the route of infection through large-scale culling of chickens, but Indonesia failed to take response measures in time, resulting in the country’s death toll increasing at the fastest rate in the world. The degree continues to increase.