It's time to get the flu vaccine again! As in previous years, the elderly, children and patients with chronic diseases are still the key groups of influenza vaccination, because the serious complications caused by influenza pose greater risks to them; Different from previous years, H5N 1 avian influenza is still spreading, and the number of infections and deaths is still increasing. Influenza prevention needs more people's attention and participation, and people also need to learn to use the effective preventive means around them-influenza vaccine!
Influenza is an acute respiratory infectious disease caused by influenza virus, and it is also a highly contagious and fast-spreading disease. It is mainly spread through droplets in the air, contact between people or contact with contaminated items. Typical clinical symptoms are: sudden high fever, general pain, obvious fatigue and mild respiratory symptoms. Generally, autumn and winter are a high incidence period, resulting in serious complications and deaths.
[Edit this paragraph] Influenza-A Brief Introduction to Diseases
The disease is caused by influenza virus and belongs to orthomyxoviridae, with a diameter of 80- 120nm, spherical or filamentous. Influenza viruses can be divided into three types: A, B and C. A virus often mutates its antigen, which is highly contagious, spreads quickly and is prone to widespread epidemic.
Symptoms: 1, sudden onset, chills, fever, body temperature rising 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 and cold
Both colds and flu are caused by virus infection. Because the virus is spread through the air, the nose bears the brunt. The virus first infects the nasal mucosa, and then continues to multiply, resulting in inflammation of the nasal mucosa, sneezing, runny nose, stuffy nose and other symptoms.
The common cold refers to the "nasal cold", and its impact on the human body is usually limited to the respiratory system. All the symptoms are related to the nose, such as runny nose, stuffy nose and sore throat, cough and even fever. It usually takes several days to recover.
Influenza is caused by influenza virus. Influenza symptoms affect the whole body, including fever, chills, sweating, general pain, headache, bone pain, muscle pain, fatigue, loss of appetite, cough, nasal congestion and so on. In severe cases, it can lead to pneumonia and other complications, which can be fatal. There are different types of influenza viruses, and new virus varieties will appear every ten years or so.
[Edit this paragraph] Influenza-Definition and Epidemiology
(1) Overview
Influenza, referred to as influenza for short, is a common acute respiratory infection caused by influenza virus, which is more common in winter and spring. Clinically, the symptoms are severe systemic poisoning, such as high fever, fatigue, headache and body aches, but there are slight respiratory catarrh symptoms. Influenza virus is easy to mutate and highly contagious, which often causes influenza epidemic. There were four world pandemics of influenza A in the 20th century. During the past half century (1953 to present), there have been 17 large, medium and small-scale influenza epidemics in China, of which two were pandemics.
(2) Etiology
Influenza virus belongs to orthomyxoviridae, spherical, with a diameter of 80- 120nm, and its genome is RNA virus. It is characterized by easy variation. It can be divided into three types: A, B and C. Among them, Type A is the most susceptible to mutation, which can infect people and many animals. It is the main pathogen of human influenza and often causes pandemics and small and medium-sized epidemics. Influenza B virus has little variation and can infect humans, causing outbreaks or pandemics. Type C is relatively stable and can infect humans, mostly sporadic cases. Pigs can also be infected at present. The influenza virus is not heat-tolerant, and it is inactivated at 100℃ 1 min or 56℃ for 30 minutes. Sensitive to common disinfectants (1% formaldehyde, peracetic acid, chlorine-containing disinfectants, etc.). ), sensitive to ultraviolet rays, resistant to low temperature and drying, and can still survive in vacuum drying or below -20℃.
⑶ Epidemiology
1, source of infection: influenza patients and recessive infected people are the main sources of infection. It is contagious 1~7 days after onset, and the most contagious is 2~3 days after onset. Animals such as pigs, cows and horses may spread influenza.
2. Transmission route: The influenza virus mainly spreads by air droplets, and it lives in the air for about half an hour, polluting daily necessities.
3. Susceptible population: generally susceptible, with certain immunity after illness. There is no cross-immunity between different subtypes of influenza III and influenza A, and they can recur.
4. Popular features:
1) epidemic characteristics: sudden onset, rapid spread, peak in 2-3 weeks, high incidence, short epidemic period, about 6-8 weeks, and often spread along traffic lines.
2) general law; Cities first, rural areas later, collective units first, and scattered residents later.
Influenza A: It often leads to epidemic situation and even world pandemic. There are 1 minor epidemics in about 2-3 years. According to the analysis of four pandemics that have occurred in the world, there is generally an epidemic from 10 to 15.
Type B influenza is an outbreak or a small epidemic, and type C influenza is mainly sporadic.
3) popular season; It can occur in all seasons, mainly in winter and spring. Influenza epidemics can also be seen in the south in summer and autumn.
[Edit this paragraph] Influenza-Clinical manifestations
(1) Overview
Typical flu onset is acute: the incubation period is several hours to 4 days, usually 1~2 days; High fever, the body temperature can reach 39~40℃, accompanied by chills, usually lasting 2~3 days; Symptoms of systemic poisoning are serious, such as fatigue, headache, dizziness and general pain; The duration is long, and the symptoms such as fatigue can last for 1~2 weeks after the body temperature is normal; Respiratory catarrh is mild, often accompanied by sore throat, and a few have stuffy nose and runny nose. A few people have nausea, vomiting, loss of appetite, diarrhea and abdominal pain. There are a few patients with digestive tract symptoms as the main performance. The elderly, infants, people with heart and lung diseases or people who receive immunosuppressants may get pneumonia after catching the flu.
(2) Clinical classification
1, simple influenza: acute onset, body temperature 39~40℃, accompanied by obvious systemic symptoms such as chills, fatigue, headache, muscle joint pain, and mild respiratory catarrh symptoms, including runny nose, stuffy nose and dry cough. Physical examination: acute disease, congestion and swelling of pharynx, no secretion, dry rales in lungs.
2, pneumonia flu: less common, more common in the elderly, children, people with original heart and lung diseases. Etiology: Primary viral pneumonia, secondary bacterial pneumonia and mixed bacterial viral pneumonia. Manifestations: persistent high fever, severe cough, expectoration of blood and phlegm, shortness of breath, cyanosis, audible and moist rales in the lungs. The chest film shows that both lungs are scattered in flocculent shadows. No pathogenic bacteria grow in sputum culture, and influenza virus can be isolated. It can die of respiratory and circulatory failure with a high mortality rate.
3. Toxic influenza: characterized by damage to the central nervous system and cardiovascular system. It is characterized by persistent high fever, decreased blood pressure, anxiety, convulsion, meningeal irritation and other symptoms of encephalitis and meningitis.
4. Gastroenteritis influenza: rare, with diarrhea, abdominal pain and vomiting as the main clinical manifestations.
(3) Complications
1, respiratory system: bacterial bronchitis, bacterial bronchitis, pneumonia
2.Reye syndrome Reye syndrome is a liver and nervous system complication of influenza A and B, and the onset age is 12~ 16 years old. There are nervous system symptoms such as nausea, vomiting, lethargy, coma and convulsion after fever. The liver is big and there is no jaundice. Cerebrospinal fluid examination is normal. It may be related to taking aspirin.
3. Others: toxic shock, toxic myocarditis,
What if you have a fever?
One of the symptoms of influenza is fever, and the body temperature can sometimes be as high as 39 to 40 degrees Celsius. At this time, many people will take antipyretics, or rub their bodies with alcohol, or ice compress to reduce their fever. In fact, at the high temperature of 37 to 40 degrees Celsius, the reproduction of influenza virus is inhibited. It can be said that fever is a signal that the human immune system is preparing for war. If forcibly suppressed, it will only weaken its own resistance and help the virus to reproduce. Some people also suggest wearing less clothes to dissipate heat. In fact, patients with wind-heat cold and wind-cold cold all have chills, even if they have a high fever. So what we have to do is to wear enough clothes to keep warm, and don't take antipyretics casually (especially taking Chinese medicine by ourselves), otherwise it will be a mistake.
But it is still recommended to see a doctor. A high fever can burn the brain or cause myocarditis. The comprehensive treatment in the hospital is specialized in reducing fever, resisting virus and diminishing inflammation. It is best to see a doctor in time (and it is recommended not to take medicine casually without the guidance of a doctor, otherwise it will be more troublesome). In short, it is strongly recommended to see a doctor in time and get the guidance of a doctor.
[Edit this paragraph] Influenza-Aspects of Chinese and Western Medicine
Western medicine's viewpoint
Western medicine believes that influenza is caused by influenza virus. Western medicine is divided into influenza A and influenza B according to virus types (see influenza ABC).
Traditional Chinese medicine view
There is no concept of virus in TCM. Influenza or cold is called "invasion of exogenous pathogens", because the origin of the virus, whether nasal mucosa or respiratory tract, belongs to viscera, so it is called "exogenous pathogens".
Traditional Chinese medicine can be roughly divided into "wind-cold cold" and "wind-heat cold" according to symptoms and physical reactions.
Symptoms of wind-heat cold: sore throat, fever, loss of appetite, runny nose (sticky, yellow-green) and thick phlegm.
Symptoms of cold and cold: fear of cold and wind, fatigue, runny nose and loss of appetite.
[Edit this paragraph] Influenza-Influenza ABC
Influenza viruses are divided into three types: A, B and C:
Type A: The most common type, which can be widely prevalent and zoonotic. For example,150,000 chickens were slaughtered by the government because of the bird flu that ravaged Hong Kong in 1997. Type A virus can be further divided into A 1 and A2 types, and then further divided according to structure, such as h5n 1 A strain (Hong Kong avian influenza virus), H3N2 type (Wuhan occurrence 1995), h 1n 1 A type (Germany/kloc). Due to irregular gene mutation, the virus derived new varieties.
Type B: It is also prevalent, with milder symptoms than Type A and no subtype.
Type C: mainly sporadic cases; There is no subdivision subtype.
What do h and n mean?
Influenza virus has lipid envelope and protein on the membrane, which is composed of hemagglutinin (H) and neuraminic acid ⅵ (N), both of which have antigenicity. The variation of influenza A virus is a common natural phenomenon, mainly H and N variation.
Generally speaking, there are three kinds of influenza virus hemagglutinin: H 1, H2 and H3. H4 to H 14 will only infect animals other than humans, such as chickens, pigs and birds. There are only two kinds of n: N 1 and N2.
[Edit this paragraph] Influenza-Laboratory examination
1. Hemogram: the total number of white blood cells is normal or decreased, and lymphocytes are increased. If complicated with bacterial infection, the total number of white blood cells and neutrophils increases.
2. Virus isolation: In the acute stage, the virus can be isolated by inoculating the patient's oropharynx gargle into chicken embryos.
3. Serum antibody detection: Two serum samples of patients in early stage (within 3 days before onset) and recovery stage (after 2-4 weeks) are positive if the antibody titer is more than 4 times.
4. Rapid diagnosis: Take the patient's nasal mucosa for staining to find inclusion bodies, and the antigen detected by immunofluorescence is ().
[Edit this paragraph] Influenza-Differentiation and Diagnosis
(1) diagnosis
clinical examination
1。 Blood routine, urine routine and white blood cell count are normal or decreased.
2。 X-ray examination
3。 Humoral immune detection
4。 germiculture
5。 Immunological detection of viral infectious diseases
Diagnosis can be made according to clinical symptoms during epidemic period and epidemic situation, but early sporadic influenza cases should be diagnosed comprehensively by combining epidemiological history, clinical manifestations and laboratory examination.
1, epidemiological history: during the epidemic period, a large number of patients with upper respiratory tract infection or patients with upper respiratory tract infection in a unit or region increased significantly.
2. The clinical manifestations are mild.
3. Laboratory inspection
1) The total number of white blood cells is normal or decreased, and the number of lymphocytes is increased.
2) Isolate influenza virus from nasopharyngeal secretion of patients.
3) The serum antibody titer increased by more than 4 times in recovery period.
4) Respiratory epithelial cell virus antigen is positive.
5) Nasopharyngeal secretion was antigen-positive after sensitive cells proliferated 1 generation.
6) Virus nucleic acid can be detected by RT-PCR.
Diagnostic classification
1) Suspected cases: clinical manifestations of epidemiological history.
2) Confirmed case: one of the 2, 3, 4 and 5 laboratory pathogenic tests of clinical manifestations in epidemiological history.
(2) Differential diagnosis
1. Common cold: It is caused by a variety of viruses, mostly sporadic, with slow onset, obvious upper respiratory symptoms and mild systemic symptoms. The common cold, also known as acute rhinitis or upper respiratory catarrh, is mainly manifested as catarrh symptoms in the nasopharynx. Most adults are caused by rhinovirus, followed by parainfluenza virus, respiratory syncytial virus, echovirus virus and coxsackie virus. Acute onset, dry throat, itchy throat or burning sensation at first, sneezing, stuffy nose and runny nose at the same time or several hours later, and thickening after 2~3 days. May be accompanied by sore throat, sometimes hearing loss due to ear pharyngitis, as well as tears, dull taste, poor breathing, hoarse voice, a small amount of cough and so on. Generally, there is no fever and systemic symptoms, or only low fever, discomfort, mild chills and headache. Examination showed congestion, edema, increased secretion of nasal mucosa, and mild congestion of pharynx. If there are no complications, it usually takes 5~7 days to recover.
2. Flu typhoid leptospirosis: It occurs frequently in summer and autumn and has a history of contact with epidemic water. In addition to fever, laboratory coagulation tests can also detect gastrocnemius tenderness, inguinal lymph node enlargement and tenderness. If the antibody titer is higher than 1: 400, the disease can be diagnosed by blood culture.
3, streptococcal pharyngitis, sore throat, swollen tonsils, purulent secretions, swollen submandibular lymph nodes, increased neutrophils, blood culture ().
4. Other viral respiratory infections such as parainfluenza virus and adenovirus infection should be distinguished by pathogenic examination.
5. Mycoplasma pneumonia should also be identified by pathogenic examination.
[Edit this paragraph] Influenza-Treatment
(A) general symptomatic treatment
Stay in bed, drink plenty of water, give a liquid or liquid diet, be suitable for nutrition, supplement vitamins, rinse your mouth with warm boiled water or warm salt water after meals, keep your mouth and nose clean, and give anti-infection treatment when systemic symptoms are obvious.
(b) Early application of antiviral therapy
1, can reduce the amount of virus detoxification, inhibit virus replication, relieve clinical symptoms, and prevent the virus from spreading to the lower respiratory tract and causing complications such as pneumonia.
2. medicine
1) amantadine is an M2 ion blocker, which can block the virus's adsorption to sensitive cells, inhibit virus replication, and is effective for influenza A ... with good efficacy within 48 hours of onset. Dosage: 200mg/ day for adults, 0/00 mg/day for the elderly and 4-5mg/kg/ day for children; Usage: Take orally twice for 3-4 days; Side effects: dry mouth, dizziness, lethargy, ataxia and other nervous system symptoms.
2) Dosage of methylamino amantadine: 100-200mg/ day. Usage: Take orally twice. Its antiviral activity is 2-4 times higher than that of amantadine, and its nervous system side effects are few.
3. Precautions: Pregnant women, people with mental disorders, and people with severely impaired liver and kidney functions are prohibited. These two drugs are prone to drug resistance.
(3) prevention and treatment of various complications
(4) Chinese medicine treatment
Method of treating influenza with traditional Chinese medicine
There is a saying in Chinese medicine that "healthy qi should be kept inside, and evil should not be done", that is to say, if you are strong, you will not be disturbed by external evil (virus). Therefore, Chinese medicine focuses on the root cause, on the one hand, it will use herbs to diminish inflammation and detoxify, on the other hand, it will improve body function and enhance immunity. If you only eliminate the discomfort caused by a cold without improving your physical condition, it is easy to be invaded by the virus again. Therefore, people who often catch a cold should pay attention, indicating that they are weak and have low resistance, so they must be adjusted appropriately.
In terms of medication, there are great changes, such as:
Anti-inflammatory, bactericidal and immunity enhancing: Radix Isatidis, Fructus Forsythiae and Flos Lonicerae can be selected.
Promote blood circulation in the head: Radix Angelicae Dahuricae, Herba Schizonepetae and Flos Chrysanthemi can be used.
Clearing heat and reducing fever: mulberry leaves can be used.
Relaxing tendons, activating collaterals and reducing fever: Radix Puerariae, Ramulus Mori and Luffa can be used.
Folk diet: Boil ginger with hot lemon.
At the beginning of a cold, many people used to go to a tea restaurant to drink a cup of hot lemon cola and stew ginger to relieve symptoms. It is said that the effect is quite good.
What is the effect of this "music"? According to the theory of Chinese medicine, ginger can invigorate qi and promote blood circulation. If it's a cold-type cold, it's cold and hot at first, and when you feel bored and have no appetite, a cup of "strong" ginger cola can really warm your stomach and drive away the cold, which is the opposite. There is also a treatment prescription that uses dried tangerine peel and ginger to cook porridge instead of three meals, which is especially suitable for people with virus entering the stomach.
As for orange juice, it is said that it can speed up the recovery from a cold. Is it true?/You don't say. Usually vitamin C supplementation can really reduce the chance of infection, but because most fruits are cold, it is easy to cause cough, so it is not advisable to eat more when coughing. You can barely eat apples or stew oranges, but the taste is of course different.
On the contrary, you might as well drink hot lemonade, because fresh lemons are rich in vitamin C, appetizing and refreshing, and honey can moisturize. If you drink it while it is hot, the itching and discomfort in your throat will really be relieved.
There is also a simple formula, which is very effective in collecting nasal water. The only drawback is the bad taste: first, boil ginger for 20 minutes, then add light fermented soybean, three strips of white garlic and 1 money (3 grams) mint leaves and cook for about 2 minutes.
[Edit this paragraph] Influenza prevention measures
(1) control the source of infection.
Early detection, early reporting, early isolation and early treatment.
Respiratory isolation 1 week or until the main symptoms disappear.
(2) cut off the route of transmission
During the 1. epidemic period, gatherings or group entertainment activities should be avoided. People of all ages who are prone to illness and disability should go to public places less, pay attention to ventilation and disinfect public places when necessary.
2. Medical personnel should wear masks and wash their hands to prevent cross infection.
3. The patient's utensils and secretions should be thoroughly disinfected.
(3) Vaccine prevention
Inactivated vaccine: the effect is good, and the vaccination targets are the elderly, children, patients with severe chronic diseases, people with low immunity and people who may be in close contact with patients; Inoculation time is 1 mid-October 10-165438+times per year, and effective antibodies can be produced in 2 weeks. Disabled in the following situations: those who are allergic to eggs; Patients with acute infectious diseases, mental patients, early pregnancy and infants under 6 months.
Attenuated live vaccine: inoculated by nasal spray.
(4) Drug prevention
For susceptible people who may be infected but have no disease, amantadine 100mg/ orally twice a day, 10- 14 days; It has a certain preventive effect on influenza A, but it has no effect on influenza B. ..
Several common small measures to prevent influenza;
1, windows are often opened indoors for ventilation to keep the air fresh.
2. Go to crowded public places less to avoid being infected with influenza virus.
3, strengthen outdoor physical exercise, improve the body's disease resistance.
4, the climate in autumn and winter is changeable, pay attention to adding and subtracting clothes.
5. Drink more boiled water and eat more light food.
6. Inject flu vaccine.
[Edit this paragraph] Flu-Flu taboo
Taboos that are easily overlooked include:
Often eat fried food: it will make the larynx congested and increase the chances of mucosal surface wounds and infections.
Close the window and keep warm: when closing the window, the air circulation is blocked, the indoor air tends to be turbid, and the microbial content rises, which is even more unfavorable to the respiratory tract.
In addition, there are many places to pay attention to:
Don't take medicine to get rid of symptoms, it should be cured: many people have stuffy nose, headache or fever, and they should be cured if they continue to work. This is actually unwise, because the cold is still not cured, and not having a good rest is equivalent to reducing your immune ability.
Eat less greasy food: greasy things such as pork soup and chicken soup may not be a big problem on weekdays, but drinking them during a cold may aggravate the condition.
Avoid sexual life during illness: it is not advisable to consume too much energy.
Wash your hair carefully in the bath to prevent colds: after taking a hot bath, your blood vessels dilate and your body temperature drops, making it easy to catch a cold again. Avoid blowing or turning on the air conditioner after washing your hair, because your hair is wet and your head is easy to catch cold.
[Edit this paragraph] Influenza-Influenza outbreak history
19 17 - 19 19
The outbreak of Spanish influenza in Europe (virus type H 1N 1) caused 20 million deaths (8.5 million in World War I alone), which was the worst influenza epidemic in history.
1957 - 1958
1957 broke out in Guizhou, China in February (the virus may come from 1956 Soviet Union), and then spread all over the world. The global incidence accounts for 10% to 30% of the total population, but the mortality rate is lower than 19 19, accounting for about 0.25% of the total population.
1968 - 1969
The flu started in Hong Kong, and the global death toll reached 700,000, of which the United States accounted for more than 30,000.
1976
A young man in New Jersey was infected with swine flu, causing panic and a new epidemic, so he was vaccinated on a large scale.
1986 - 1993
There have been several cases of human swine flu infection in different parts of the world.
1997
Avian influenza occurred in Hong Kong, and the virus that originally only affected chickens also made people sick. The Hong Kong government ordered the slaughter of 6,543,800+500,000 chickens. Number of people affected 18, including 6 deaths.
[Edit this paragraph] Influenza-References
[1]. Huang, Hong Tao, Liu Chongbai, et al. Basic and experimental techniques of medical virology. Beijing: Science Press, 1990.
[2]. Wang Jianhua, Zhang Jinfeng, Prevention and Treatment of Influenza, People's Military Medical Publishing House, 2005, 1 1.
[Edit this paragraph] Tripartite folk dietotherapy for influenza
Cold diet prescription?
Symptoms include fever, aversion to cold, headache, body cold and runny nose. ?
Ginger brown sugar tea: 1 slice of ginger, appropriate amount of brown sugar, brewed with boiling water instead of tea. ?
Onion porridge: 30g of glutinous rice and 2 slices of ginger, mashed, add onion 1 knot, add rice vinegar 1 ml, and drink while it is hot.
Perilla porridge: 25 grams of white rice, cooked in the normal way, and 5 grams of perilla leaves are added when cooked.
Prescription for treating wind-heat cold
The symptoms are fever, slight aversion to cold, headache, cough, sore throat and red eyes. ?
Chrysanthemum tea: 5 grams of chrysanthemum, brewed with boiling water, no tea. ?
Sangju Douchi drink: 5 grams of chrysanthemum, 5 grams of mulberry leaves and 3 grams of douchi, decocted. ?
Mint reed root drink: reed root 30 cm, mint 25 g, decocted in water.
Cabbage and mung bean drink: cabbage head 1 piece, washed and sliced, mung bean sprouts 15g, decocted in water for drinking. ?
Shi Feng cold diet prescription
Symptoms are fever, headache, dizziness, stuffy nose, heavy voice, drowsiness and fatigue, and nausea. ?
Huoxiang drink: 5 grams of fresh Huoxiang leaves, appropriate amount of sugar, decocted.
[Edit this paragraph] Four dietary taboos of influenza
Influenza is an acute respiratory infectious disease caused by influenza virus, which is highly contagious and has a rapid onset. Although it is easy to cure, it is very easy to cause repeated colds because of the weak physique and unreasonable diet of infants and young children. Therefore, in addition to drug treatment, diet conditioning is also indispensable for colds.
1. Eating salty food can easily shrink the mucosa of the affected area, and aggravate symptoms such as nasal congestion and throat discomfort. Moreover, salty food is easy to produce phlegm and stimulate local cough.
2. Fasting sweet and greasy food: Sweetness can help wet, and greasy food is not easy to digest, so people with colds should avoid all kinds of sweets, drinks and fats.
3. fasting spicy food: spicy food is easy to hurt body fluids, help fire and produce phlegm, and make phlegm difficult to cough up. So people who have a cold should not eat it, especially onions.
4. It is not advisable to eat barbecue and fried foods: the smell of such foods stimulates the respiratory tract and digestive tract, which easily leads to mucosal contraction, aggravates the condition and is not easy to digest.
Childhood influenza
[symptoms]
1. School-age children and adolescent children: They show a typical cold similar to adults, and they attack quickly.
2. Fever (39-40℃), muscle aches, chills, headache, facial flushing, malaise, runny nose, cough and conjunctivitis may occur.
3. Type B cold: the symptoms of eyes and nose are obvious, but the systemic symptoms are not obvious.
4. When there are no complications, white blood cells are mostly normal.
5. Young children have great clinical changes.
6, usually have obvious fever, moderate rhinitis, runny nose, and sometimes fever convulsions, diarrhea, otitis media, rash and so on.
7, can cause larynx, trachea, bronchitis, bronchiolitis, pneumonia, etc.
[Notes]
1. Stay in bed and replenish proper water.
2. Wear a mask and isolate it to avoid infection.
3. If there is secondary bacterial infection, use antibiotics according to the doctor's advice.
Human and domestic avian influenza
(hereinafter referred to as human avian influenza A (H5N 1) virus) is an acute respiratory infectious disease caused by some subtypes of avian influenza A virus. In May, children aged 1997 and 1 3 in China SAR died of unexplained multiple organ failure. In August of the same year, it was identified as human influenza caused by avian influenza A virus H5N 1 by the US Centers for Disease Control and Prevention and the World Health Organization (WHO) National Influenza Center in Rotterdam, Netherlands. This is the first time in the world that avian influenza A virus H5N 1 infects humans. Later, it was reported that H9N2 and H7N7 subtypes infected humans, and H5N 1 infected humans again.
Influenza, referred to as influenza for short, is a common acute respiratory infectious disease caused by influenza virus, which has strong spread and is often endemic. When people lack immunity to new influenza virus variants, it will lead to worldwide epidemic, which is characterized by sudden occurrence and rapid spread. From 19 18+09 19, a very widespread epidemic occurred in the world, which led to 2009.
I. Etiology
Avian influenza virus belongs to influenza A virus. Influenza A virus is polymorphic, with a spherical diameter of 80 ~ 120 nm and an envelope. The genome is a segmented single negative strand RNA. According to the antigenicity of hemagglutinin and neuraminidase, it can be divided into 15 H subtype (H 1 ~ H 15) and 9 N subtype (N 1 ~ N9). In addition to humans, influenza A virus can also infect pigs, horses, marine mammals and poultry.
Hemagglutinin, abbreviated as H, is a rod-shaped process, which has the characteristics that viruses attach to sensitive receptors and cause agglutination of red blood cells in many animals.
Neuraminidase, abbreviated as N, is a dumbbell-shaped process, which can hydrolyze the glycoprotein N- acetylneuraminic acid on the cell surface and release the replicated virus from the cell surface.
H5N 1, H9N2 and H7N7 are the main subtypes of avian influenza virus that infect humans, and the patients infected with H5N 1 are seriously ill and have high mortality.
Second, epidemiology.
1, source of infection and route of transmission
(a) the source of infection is mainly chickens, ducks, geese and other poultry, especially chickens, who suffer from avian influenza or carry avian influenza virus; But it does not rule out the possibility that other birds or pigs will become the source of infection. Patients are the main source of infection, especially mild patients and recessive infected people, because they are not easy to be found and have a wide range of activities. It has been proved that animal (pig, horse, bird) influenza virus is homologous to human influenza virus, so animal influenza can be transmitted to people, but most of them play a role of starting factor or long-distance transmission in the early stage of epidemic.
(2) The route of transmission is mainly through respiratory tract, through close contact with infected birds and their secretions and excretions, and direct contact with virus strains in water contaminated by virus. There is no conclusive evidence of human-to-human transmission.
2. Immunity Humans are usually susceptible to influenza virus. Immunity to the same virus was obtained after infection, but the maintenance time was short, only 8 ~ 12 months, not more than 2 years.
② Local resistance: The infection is mostly the surface infection of local mucous membrane of respiratory tract, the virus does not invade the blood, the incubation period is short, and the role of serum antibody in preventing infection is limited and not lasting, so local immunity is more important. Local mucosa secretes specific SIgA soon after being infected by virus, which plays an important role in local protection against virus invasion.
① Systemic resistance: It is related to the level of specific antibodies in blood. The levels of neutralizing antibody and hemagglutination inhibitory antibody are often parallel, reaching the peak at 2 weeks after illness, then gradually decreasing, and then falling to the pre-illness level after 8 ~ 12 months. A, antibodies from the blood into the tissue and its secretions, can play a role in preventing virus invasion and reproduction. B, newborns can get passive immunity from their mothers, which drops obviously in the second to third month and disappears completely in the seventh month. C, children of different ages have different blood antibody compositions due to different influenza virus epidemic strains. Cellular immunity has proved that the fatality rate of NK cells and interferon activity increase after infection.
(3) Susceptible people generally think that they are susceptible at any age, but the incidence of children under 12 years old is higher and the condition is more serious. Close contact with birds who died of unknown reasons or infected or suspected infected with avian influenza is a high-risk group.
3. Age
Children and adolescents suffer from this disease, and the highest incidence rate is 5-20 years old. Infants under 4 ~ 5 months are less infected. When the new subtype caused the epidemic, the incidence rate of each age group was similar, but it was still mostly children aged 5 ~ 14, and the infection rate was nearly 50%.
4. season
Generally, temperate and cold temperate influenza is prevalent in late winter and early spring, and it is more serious in winter.