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Information leaflet on human infection with H7N9 avian influenza
Q&A on popular science knowledge of human infection with H7N9 avian influenza

1. What is the flu?

Influenza, referred to as influenza, is an acute respiratory infectious disease caused by influenza virus. The most common flu is sudden onset, chills and high fever, and the body temperature can reach 39 ~ 40℃, accompanied by headache, muscle joint pain, extreme fatigue, loss of appetite and other systemic symptoms, such as sore throat, dry cough, stuffy nose and runny nose. If there are no complications, symptoms will improve after 3 ~ 4 days of onset, but cough and physical recovery often take 1 ~ 2 weeks. Mild patients, such as the common cold, have mild symptoms and can be cured in 2 ~ 3 days.

2. What is avian influenza?

Avian influenza mainly refers to infectious diseases caused by influenza virus prevalent in poultry. Avian influenza virus can be divided into highly pathogenic avian influenza virus, low pathogenic avian influenza virus and non-pathogenic avian influenza virus. At present, only H5 and H7 subtypes of highly pathogenic avian influenza viruses have been found. Due to the barrier of species, avian influenza virus can only infect people occasionally. Previously confirmed avian influenza virus infections were H5N 1, H9N2, H7N2, H7N9, H5N2 and H 10N7, with different symptoms, including respiratory symptoms, conjunctivitis and even death. People infected with highly pathogenic H5N 1 avian influenza virus often show respiratory symptoms such as high fever, which often develops into pneumonia, even acute respiratory distress syndrome, systemic organ failure and even death.

3. What is H7N9 avian influenza virus?

Influenza viruses can be divided into three types: A, B and C. Among them, influenza A can be divided into 1- 16 subtype according to the different hemagglutinin protein (HA) of influenza virus, and 1-9 subtype according to the different neuraminidase protein (NA) of virus. Different subtypes of HA can combine with different subtypes of NA to form different influenza viruses. Birds, especially waterfowl, are the natural reservoir of all these influenza viruses, and H7N9 avian influenza virus is one of them. In the past, H7N9 subtype influenza virus was only found in birds, and there were outbreaks in birds in the Netherlands, Japan and the United States, but no abnormal infection was found.

4. What is the epidemic situation of people infected with H7N9 avian influenza in our city?

Up to now, no suspected or confirmed cases of human infection with H7N9 avian influenza have been reported in our city.

5. What are the main clinical manifestations of 5.H7N9 avian influenza infection cases?

The main clinical manifestation is typical viral pneumonia, with acute onset, high fever (above 38℃), cough and other respiratory infection symptoms at the initial stage. Dyspnea, severe pneumonia and progressive aggravation occur within 5-7 days after onset, and some cases can rapidly develop into acute respiratory distress syndrome and die.

At present, the understanding of the clinical characteristics of the disease is still very limited, and it is not clear whether viral infection can cause mild cases or other clinical manifestations. With the accumulation of more case information, the understanding of the disease will change.

6. What is the global situation of human infection with influenza A H7 virus?

1996 ~ 2009, the Netherlands, Italy, Canada, the United States and the United Kingdom reported cases of influenza A (H7N2, H7N9 and H7N9). The main clinical manifestations are conjunctivitis and mild upper respiratory tract infection. Previously, no cases of H7 subtype influenza virus infection have been found in China.

7. How does the virulence and infectivity of 7.H7N9 virus compare with previous seasonal influenza cases such as H 1N 1 and H5N 1?

At present, there are few confirmed cases of human infection with H7N9 avian influenza virus, and the research data on the virus and its diseases are very limited, so it is impossible to make an accurate judgment on the virulence and interpersonal transmission ability of the virus.

8. What is the source of infection of this person infected with H7N9 avian influenza?

Human infection with H7N9 influenza virus belongs to avian influenza virus in virus biology. Most influenza viruses infected with H7 subtype in the world also come from poultry, but up to now, the specific source of infection of confirmed cases is still unclear.

9. Will 9.H7N9 avian influenza virus spread from person to person?

It has not been proved that the virus has the ability of interpersonal transmission.

10. How to prevent H7N9 influenza?

Influenza is an acute respiratory infectious disease. Washing hands frequently, indoor ventilation frequently, paying attention to nutrition and keeping healthy are conducive to preventing respiratory infectious diseases such as influenza. When symptoms of respiratory tract infection such as sneezing and coughing appear, cover your mouth and nose with paper towels and handkerchiefs to prevent infection. In addition, special attention should be paid to avoid direct contact with dead poultry and livestock.

There is no vaccine against H7N9 avian influenza virus at present.

1 1, current treatment?

Gene sequence analysis showed that the virus was sensitive to neuraminidase inhibitors as anti-influenza drugs. According to the experience of antiviral treatment of other types of influenza, it may be effective to use neuraminidase inhibitors as anti-influenza drugs in the early stage after onset, but the specific treatment of newly discovered H7N9 avian influenza virus infection still needs to be observed and studied.

12. How can the public protect themselves?

Keeping personal hygiene habits such as washing hands frequently and covering your mouth and nose when coughing and sneezing can effectively prevent respiratory infectious diseases such as influenza. At the same time, contact with dead poultry and livestock should be avoided.

13. Is there a big risk of public infection with H7N9 avian influenza virus?

At present, only a few cases have been found in the local area, and no follow-up cases have been found by close contacts of cases through medical observation. According to the limited evidence at present, the risk of public infection with the virus is low.

14. Is the risk of medical staff being infected with H7N9 avian influenza virus high?

At present, there is no definitive evidence of human-to-human transmission of H7N9, and no infected cases have been found among the medical staff who received the confirmed cases. However, because medical staff have more opportunities to contact patients with infectious diseases than the general public, it is suggested that medical staff take necessary protective measures in the process of diagnosis and treatment of patients. When accepting suspected or confirmed cases of H7N9 avian influenza, standard prevention plus droplet transmission prevention and contact prevention should be adopted.

15. What actions have been taken by relevant domestic departments at present?

After the case appeared, the local health department attached great importance to it and took timely measures such as patient treatment, epidemiological investigation, specimen collection and inspection, medical observation of close contacts, and strengthened the monitoring of unexplained pneumonia cases.

The National Health and Family Planning Commission attaches great importance to the epidemic situation. After receiving the report of severe unexplained pneumonia, we immediately sent an expert working group to Shanghai, Anhui and Jiangsu to guide the local patient treatment and investigation, held a multi-departmental meeting to analyze and judge the nature of the epidemic, and arranged the deployment of relevant investigations, prevention and control, and response preparations.

The National Center for Disease Control and Prevention (CDC), after receiving case reports and samples for inspection, quickly carried out epidemic risk judgment and laboratory testing research, made etiological diagnosis of the cases in a short time, discovered and confirmed the human infection cases caused by the new H7N9 avian influenza virus for the first time in the world, and made in-depth analysis of the characteristics of the new virus.

16. How to prevent people from being infected with H7N9 avian influenza?

Ordinary citizens

1. Buy poultry and poultry products through formal channels, and pay attention to appearance and quality. During the epidemic of avian influenza, try not to buy live birds, especially don't buy live birds home to keep them.

2, cooking poultry products, should be heated to boiling, steamed before eating.

3. In the process of poultry food production, raw and cooked products are separated, containers are separated, and knives and boxes are separated.

4. Avoid letting children touch birds and poultry.

Occupational population in close contact with poultry

1. Don't put poultry in the house where you live.

2. Wear work clothes and masks during poultry breeding, transportation, sales and slaughter, and wash your hands after touching poultry.

3. Clean the henhouse, poultry house and external environment regularly, and wear work clothes, hats and masks when cleaning.

4, poultry manure and dirt should be unified disinfection after treatment.

5. Once you find yourself or people around you with flu symptoms such as fever, cough and headache, you should see a doctor in time and explain your contact history with poultry to the doctor.

Prevention and control knowledge of H7N9 avian influenza

1. What is avian influenza?

Avian influenza virus belongs to orthomyxoviridae influenza A virus. According to the antigenicity of hemagglutinin (H) and neuraminidase (N), it can be divided into 16 H subtype (H 1 ~ H 16) and 9 N subtype (N 1 ~ N9). Avian influenza A virus can infect not only birds, but also humans, pigs, horses, minks and marine mammals. The subtypes of avian influenza virus that previously infected humans were H5N 1, H9N2, H7N9, H7N2 and H7N9. This report says that people are infected with H7N9 avian influenza virus, which is a new recombinant virus, and its internal gene comes from H9N2 avian influenza virus. The H7N9 avian influenza virus isolated from poultry and pigeons is a brand-new virus, which is highly homologous to the virus isolated from human body and has never been isolated in China before.

Avian influenza virus is generally sensitive to heat and has strong resistance to low temperature. Heating at 65℃ for 30 minutes or boiling at (100℃) for more than 2 minutes can inactivate it. The virus can survive for 65,438+0 weeks in low-temperature feces and 65,438+0 months in 4℃ water, and has certain resistance to acidic environment, and also has certain viability at pH4.0, and can maintain vitality for more than 65,438+0 years in the presence of glycerol.

Second, the prevalence, spread and clinical symptoms of H7N9 avian influenza

The source of H7N9 avian influenza virus is unknown, and the transmission route is unknown. The possibility of its introduction into China through migratory birds cannot be ruled out. The virus can infect chickens, pigeons and other poultry, with low pathogenicity to poultry and no clinical symptoms after infection. So far, pigs have not been infected with this virus.

The source of human infection is still unclear. There is no conclusive evidence of human-to-human transmission.

Human clinical manifestations: generally flu-like symptoms, such as fever, cough and scanty phlegm, may be accompanied by headache, muscle aches and general malaise. Severe symptoms are severe pneumonia, body temperature above 39℃, dyspnea and hemoptysis. Acute respiratory distress syndrome, mediastinal emphysema, septicemia, shock, disturbance of consciousness and acute kidney injury can develop rapidly.

Third, prevention and control of H7N9 avian influenza

(1) Preventing poultry from being infected with H7N9 avian influenza

Comprehensive preventive measures must be taken to prevent H7N9 avian influenza. Do not introduce breeding eggs and poultry from epidemic areas; Strictly disinfect passing vehicles and the surrounding environment, incubation halls, incubators, poultry cages, staff clothes and shoes, etc. ; Adopt all-in and all-out feeding methods to prevent contact between birds and birds; The farm should have a special passage for the staff to enter and exit, and the staff and their daily protective equipment should be cleaned and disinfected reliably; It is strictly forbidden for all outsiders to enter or visit the animal breeding area. Vaccination should be carried out as required, and serological monitoring should be carried out regularly to ensure the reliable immune prevention effect of the vaccine.

(2) Prevention and treatment of human infection with H7N9 avian influenza

Influenza is an acute respiratory infectious disease. People who are mainly engaged in poultry breeding, selling, slaughtering, processing and cooking, as well as those who have been exposed to poultry within 1 week before onset, should pay attention to self-protection, and take measures such as washing hands frequently, indoor ventilation frequently, paying attention to nutrition and keeping healthy, which is conducive to preventing respiratory infectious diseases such as influenza. If there are symptoms of respiratory infection such as sneezing and coughing, cover your mouth and nose with paper towels and handkerchiefs to prevent infection. In addition, special attention should be paid to avoid direct contact with dead poultry and livestock.

On April 6, the relevant person in charge of the US Food and Drug Administration introduced that Paramivir Sodium Chloride Injection is the first neuraminidase inhibitor for intravenous administration in China, which is suitable for treating influenza A. ..

(Note: The above information comes from the official websites of www.moh.gov.cn, the National Health and Family Planning Commission of People's Republic of China (PRC), and the Ministry of Agriculture).