Discuss the problem of influenza virus

Influenza is caused by influenza virus (RNA virus).

Influenza, referred to as influenza for short, is an acute respiratory infection caused by influenza A, B and C viruses respectively. Influenza A virus often appears in the form of epidemic diseases, which may cause a worldwide epidemic of influenza. It is widely distributed in animals, and can also cause animal influenza epidemic, resulting in a large number of animal deaths. Influenza B virus often causes local outbreaks, but it does not cause worldwide epidemic influenza. So far, there is no conclusive evidence that it exists in animals other than humans. Influenza C virus mainly appears in scattered form, mainly attacking infants, and generally does not cause epidemic. Pigs are also one of its natural repositories.

The most remarkable epidemiological characteristics of influenza are: sudden outbreak, rapid spread, wide spread and strong seasonality (the epidemic situation in northern China generally occurs in winter, and it mostly occurs in summer and winter in southern China). Generally, the epidemic will stop naturally after 3-4 weeks (there are always 2-3 waves of epidemics in the world), with high incidence but low mortality. The highest infection rate is among teenagers, and the high-risk group is elderly, weak or chronically ill. After every influenza epidemic, it will always cause people to die to varying degrees.

How can we avoid the flu in winter?

From autumn to winter, colds and colds caused by seasonal changes are common, and winter is the high incidence season of influenza. Millions of people get the flu every year, and even severe cases need hospitalization. How to effectively prevent it?

1. Vaccinate in time

The protection of influenza vaccine can reach 70%-90%. Even if you get the flu after vaccination, you can alleviate its symptoms and reduce the chance of complications. Experts suggest that it is best to vaccinate in 10 and 1 1 month. Middle-aged and elderly people over 50 years old and children aged 6 months to 5 years old should use injectable vaccine, and people aged 5-49 can use nasal spray vaccine.

2. Avoid contact with public goods

Avoiding contact with public goods can reduce the chance of infection. Such as bank pens, public telephones, door handles, etc.

3. Always keep hand sanitizer and wash your hands more.

Hand sanitizer has antibacterial effect, but it should be used correctly. Experts remind that after applying hand sanitizer, wipe 10- 15 seconds, and your hands are still wet, which means that the amount of hand sanitizer is enough, and then rinse them off. You can also choose sterile paper towels with an alcohol concentration of at least 60%.

4. Make more friends and communicate more.

The latest research found that friendship can not only reduce mental stress, but also promote physical health. Compared with people who stay in small groups and often feel lonely, people with extensive social contacts can produce more influenza antibodies.

Put proper pressure on yourself.

When people feel stressed, the body will send out warning signals, release decompression hormones and adrenaline, and the immune system will produce more immune cells. But if the pressing time is too long, it will have a negative effect. So you can try to set a realistic short-term goal for yourself, which will help to enhance your immunity.

6. Do more exercise and massage

People who can be active for three hours a day are 35% less likely to get the flu than those who are less active. Experts suggest that it is best to exercise three times a week, walking fast, climbing stairs or playing table tennis.

Experts also suggest that you can do more massage at ordinary times. Whether it is professional massage or knocking on the back between husband and wife, it can increase the contents of serotonin and dopamine in the blood, thus improving immunity.

7. Don't blindly supplement vitamins

Taking a lot of vitamins every day is unlikely to reduce the risk of influenza, but it will be harmful to health. The best way is to take food supplements, or you can take multivitamins once a day. You can choose a multivitamin preparation containing vitamins A, B6, B 12, C, D and minerals such as folic acid, selenium, calcium and zinc. In addition, it is best to contain a small amount of fat in food, because some vitamins must be dissolved in lipid substances to be absorbed and utilized by the human body.

8. Take ginseng and astragalus.

Ginseng and astragalus can stimulate bone marrow to produce white blood cells, which can produce antibodies and interferon with antiviral effect. Taking 200 mg ginseng capsules orally every day can reduce the risk of influenza by 30%. Taking two 500 mg Astragalus capsules three times a day for more than three months can keep the human body immune enough.

9. Ensure sleep

Getting enough sleep in winter is the most important thing. Researchers at the University of Chicago found in experiments that people who sleep only 4 hours a day will produce half of the antibodies compared with those who sleep 7.5-8.5 hours a day.

10. Take drugs to treat influenza

If you are unfortunately infected with the flu virus, you can take the medicine according to your doctor's advice.

Prevent influenza in early spring.

When winter goes and spring comes, everything recovers. Bacteria and viruses will also grow rapidly and multiply very rampant under this suitable temperature and humidity condition, especially influenza bacilli and viruses, which are not only highly contagious, but also prone to outbreaks.

Influenza, referred to as influenza, is an acute respiratory infectious disease caused by influenza virus. Influenza can cause upper respiratory tract infection, pneumonia and various diseases outside the respiratory tract.

Typical symptoms of influenza infection: 1, sudden onset, chills, fever, body temperature rises to the peak within a few hours to 24 hours, 39 ~ 40℃ or even higher. Accompanied by headache, body aches, fatigue, loss of appetite. Respiratory symptoms are mild, such as dry throat, sore throat, dry cough and diarrhea. 2, facial flushing: conjunctival congestion, pharyngeal congestion, soft palate with hair follicles.

Influenza bacilli and viruses exist in the nasal cavity, oral mucosa and bulbar conjunctiva of susceptible people, and mainly spread in the form of droplet nuclei, which can be spread by sneezing, coughing and talking. And it is easy to spread in crowded places. Therefore, in order to prevent influenza, please do the following ten aspects of preventive health care:

1, strengthen exercise and improve your own resistance;

2. To develop good hygiene habits, wash your hands with soap or hand sanitizer under running water before meals, after defecation and when you return from going out, and wash your hands thoroughly; Frequently wash the nasal cavity with normal saline;

3, according to the weather changes, timely increase or decrease clothing;

4. The doors and windows in the home should be regularly opened for natural ventilation, not less than 2 hours a day;

5. When the sun shines, the bedding should be dried for about 2 hours to play a bactericidal role, not less than 1 time per week;

6. Eat nutritious and digestible food every day, drink more boiled water and eat some fruits properly;

7. Ensure adequate sleep;

8, to public occasions, try to wear a mask;

9, can be injected with flu vaccine, enhance the body's immunity.

classify

First of all, the typical flu

At first, it can be manifested as chills and fever, and the body temperature can be as high as 39-40℃. At the same time, patients feel headache, general pain and weakness, and often feel dry eyes, dry throat and mild sore throat. Some patients may sneeze, have a runny nose and a stuffy nose. Sometimes gastrointestinal symptoms can be seen, plus nausea, vomiting and diarrhea.

Fever and above symptoms generally reach the peak in 1-2 days, and the symptoms disappear in 3-4 days. Fatigue and cough can last 1-2 weeks.

Second, mild flu.

Acute onset, mild onset, mild systemic symptoms and respiratory symptoms.

Third, pneumonia flu.

That is, influenza virus pneumonia, the condition is rapidly aggravated within 24 hours, characterized by high fever, fatigue, irritability, severe cough, dyspnea, cyanosis, coughing up blood with phlegm, wet rales and wheezing in both lungs, rapid pulse and high mortality. This kind of patients are rare, mainly in patients with original heart disease or chronic lung disease or pregnant women.

Fourth, influenza encephalitis.

The patient had a sudden attack, which was very serious from the beginning. Often manifested as high fever, unconsciousness, neck stiffness, convulsions and other encephalitis symptoms.

The main types of influenza faced by human beings in the 20th century.

19 18

"Spanish influenza" (virus H 1N 1 similar to swine flu virus) may come from pig or poultry hosts with the variant H 1N 1 virus.

The epidemic has killed 20 million people all over the world.

1957

"Asian Influenza" (H2N2), an animal originating in Asia, is infected with both human H 1N 1 virus and avian H2N2 virus strain.

Major epidemic, H 1N 1 virus disappeared.

1968

"Hong Kong Influenza" (H2N2) probably originated from an animal in Asia and was cross-infected with human H2N2 virus strain and avian H3Nx virus strain.

Major epidemic, H2N2 virus disappeared.

1977

"Russian flu" (H2N2)

The origin of the virus is unknown, but it has exactly the same characteristics as the virus prevalent in 1950, and reappeared in China and Russian almost simultaneously.

Malignant transmission mainly affects people born after 1950s, from 1977 H 1N 1 virus and H3N2 virus all the time.

1976

"Porcine virus" (H 1N 1), New Jersey, USA. This endemic virus has appeared in American pigs since at least 1930.

There was a local epidemic in a military camp, and there were 1 death cases in some areas, and very few cases were spread to humans.

1986

Netherlands H 1N 1. Porcine virus originated from poultry.

1988

"Porcine virus" (H 1N 1), Wisconsin, USA. Porcine virus

A pregnant woman died after contact with a sick pig.

1993

H3N2, Netherlands. The "ancient" human H3N2 (similar to the virus prevalent from 1973 to 75) was recombined by H 1N 1 of pigs and poultry.

Two children were slightly infected. Suspected that his father was infected by contact with pigs.

1995

H7N7, UK. duck virus

An adult suffers from conjunctivitis.

1997

"Avian Influenza" (H5N 1), Hong Kong. poultry

18 cases were diagnosed with infection and 6 cases died.

1999

H9N2, Chinese mainland and Hongkong. Quail influenza-like virus

2 cases had mild infection.

diagnose

Epidemiological data is one of the main basis for the diagnosis of influenza. It is not difficult to diagnose with typical clinical manifestations, but it is difficult to diagnose sporadic or mild cases in the early stage of epidemic. Diagnosis usually requires laboratory examination. The main diagnosis basis is as follows:

1. Epidemiological history: In the epidemic season, a large number of patients with upper respiratory tract infection or patients with upper respiratory tract infection in hospital outpatient and emergency departments increased significantly.

2. Clinical symptoms: sudden onset of poisoning symptoms such as chills, high fever, headache, dizziness, general aches and fatigue. May be accompanied by sore throat, runny nose, tears, cough and other respiratory symptoms. A few cases have anorexia, accompanied by gastrointestinal symptoms such as abdominal pain, bloating, vomiting and diarrhea. The clinical symptoms of infant influenza are often atypical, and febrile convulsions can be seen; Some children have laryngotracheal bronchitis, and severe cases have airway obstruction. Although neonatal influenza is rare, once it occurs, septicemia often occurs, such as drowsiness, milk excretion and apnea. Often accompanied by pneumonia, the mortality rate is high.

3. Laboratory examination: ① Peripheral blood picture: the total number of white blood cells is not high or decreased, and lymphocytes are relatively increased. ② Virus isolation: influenza virus was isolated from nasopharyngeal secretion or oral gargle. ③ Serological examination: The titer of anti-influenza virus antibody increased more than 4 times in the initial stage and recovery stage, which is helpful for retrospective diagnosis. ④ The patient's respiratory epithelial cells were positive for influenza virus antigen. ⑤ After the sensitive cells were passaged overnight, the samples were positive for influenza virus antigen.

4. Diagnostic classification: suspected cases: epidemiological history and clinical symptoms; Confirmed cases: Suspected cases meet ② or ③ or ④ or ⑤ through laboratory examination.

differential diagnosis

① Common cold: The clinical manifestations of influenza are nonspecific and easily confused with the common cold. In addition to collecting epidemiological data, the general symptoms of influenza are usually more serious than those of the common cold, while the local symptoms of the common cold are more serious.

② Other systemic or upper respiratory tract infectious diseases.

Basic principles of influenza treatment

1. Isolate patients: strengthen ventilation and air disinfection in public places during the epidemic.

2. Early application of anti-influenza drugs: Only early application of anti-influenza drugs (within 3 days of onset/kloc-0) can achieve the best effect.

3. Strengthen the support for the treatment and prevention of complications: rest, drink plenty of water, pay attention to nutrition, and the diet should be easy to digest, especially for children and elderly patients. Closely observe and monitor complications, and use antibiotics only when there is clear or sufficient evidence to show secondary bacterial infection.

4. Rational use of symptomatic drugs: Early application of anti-influenza drugs can effectively improve symptoms. When antiviral drugs are used in the late stage of the disease or unconditionally, symptomatic treatment can be given, and antipyretics, nasal congestion relieving drugs, cough relieving and expectorant drugs can be used. Children are forbidden to use aspirin or aspirin-containing drugs and other salicylic acid preparations, because these drugs are related to Raynaud's syndrome, which is a liver and nervous system complication of influenza and occasionally leads to death.

Antiinfluenza drug therapy

There are two kinds of anti-influenza drugs: ion channel M2 blockers and neuraminidase inhibitors. M2 blockers are only effective for influenza A virus, and drug-resistant strains can be isolated from about 30% of the treated patients. Neuraminidase inhibitors have a good effect on influenza A and B viruses, and the incidence of drug resistance is low.

1. M2 blocker for ion channel: amantadine15 mg/kg/d for 9 years, twice, 10 ~ 16 years, twice a day and rimantadine.

Its central nervous system side effects include nervousness, anxiety, inattention and slight headache, and the incidence of amantadine is higher than that of rimantadine. Gastrointestinal reactions are mainly nausea and vomiting. These side effects are generally mild, and most of them can disappear quickly after stopping taking drugs.

Dose adjustment of patients with renal insufficiency: When creatinine clearance rate is less than ≤50m l/min, the dosage of amantadine should be reduced, and the adverse reactions should be closely observed, and the drug can be stopped if necessary. Hemodialysis has little effect on the clearance rate of amantadine. Creatinine clearance rate

2. Neuraminidase inhibitors: At present, there are two varieties, namely oseltamivir (Tamiflu) and zanamivir. At present, only oseltamivir is approved for clinical use in China. Oseltamivir: 75 mg for adults, twice a day for 5 days. Medication should be started within 2 days after symptoms appear. Children with body weight 15 kg use 30 mg, 15 ~ 23 kg use 45 mg, 24 ~ 40 kg use 60 mg, and over 40 kg use 75 mg. 65438+ is not recommended for children under 0 years old.

Adverse reactions such as nausea and vomiting of oseltamivir are rare, and there are also reports of abdominal pain, headache, dizziness, insomnia, cough and fatigue. Creatinine clearance rate