Source: [Healthy China]
Recently, the positive rate of influenza tests in some southern provinces has continued to rise, and emergency warnings have been issued successively in Fujian, Guangdong, Hainan, Jiangxi and other places. According to the National Influenza Center's weekly flu situation, the epidemic intensity of flu this summer has increased significantly compared with the same period in the past two years. At the same time, influenza activity in northern my country is at an extremely low level.
Why does this wave of flu favor the south in summer?
How to distinguish influenza virus infection from new coronavirus infection by symptoms?
How can we stand in an "invincible place" without being humble or arrogant in the face of influenza?
Let us listen to the opinions of experts.
Why do summer flu occur in the south have high incidence of summer
This influenza is mainly "A type 3", that is, A (H3N2) subtype influenza virus . The prevalence of influenza has a relatively large relationship with its geographical location and subtype of influenza. According to the "Technical Guidelines for Influenza Vaccination in China (2021-2022)" released by the Chinese Center for Disease Control and Prevention , the annual periodicity of influenza A (type A) in my country increases with the increase of latitude, and shows diversified spatial patterns and seasonal characteristics: northern provinces north of 33 degrees north latitude are in winter prevalence, with January to February each year being their single-year peaks; southern provinces south of 27 degrees north latitude show a single-year peak in April to June each year; the mid-latitude areas between the two show a bicyclical peak in January to February and June to August each year. Influenza B (type B) is reported to be in a single winter in most parts of my country.
This year, the A(H3N2) subtype influenza virus that prevails in southern provinces this year, also meets the above-mentioned single-year peak in southern provinces south of 27 degrees north latitude from April to June each year. At the same time, the bicyclical peak in mid-latitude areas also includes June to August. This is why this summer's flu mostly rages in the southern region, while the northern region is relatively peaceful.
. Are the main targets of invasion children?
Influenza caused the pediatrics in hospitals in many places to be overcrowded. Therefore, many people believe that the main target of influenza is children, and they speculate that this is related to the fact that children stay at home for too long and their simple and clean environment has caused their immunity to decline.
In fact, influenza virus is generally susceptible to the population. According to statistics from the Shenzhen Center for Disease Control and Prevention, 48% of the influenza patients this time are children aged 0 to 14, less than half. Moreover, the impact of influenza infection rate is multifaceted, but the infection rate will not be increased due to the simple and clean home environment.
Everyone has the above illusion mainly because the child care institutions and schools where children (especially school-age children) are crowded places, which are conducive to the spread of the disease and are prone to clustered cases. At the same time, after children are infected with the influenza virus, the detoxification time may last more than one week (the virus generally continues to detoxify in human respiratory secretions for 3 to 7 days), which also increases the chance of influenza transmission.
Children are usually active and have more contact with others, objects and the environment, but they generally cannot consciously hygienize their hands. In addition, children's immune system is not yet mature and is susceptible to infectious diseases of the respiratory tract. These do increase the probability of influenza virus infection in children.
How to quickly identify whether you have influenza
According to the "Influenza Diagnosis and Treatment Plan (2020 Edition)", the main symptoms of influenza are fever, headache, myalgia and general discomfort, and the body temperature can reach 39℃~40℃, which are chills and chills, and are often accompanied by systemic symptoms such as soreness in the muscles and joints, fatigue, and loss of appetite. They often have sore throat and dry cough, and may have local symptoms such as nasal congestion, runny nose, poststernum discomfort, flushing face, congestion in the conjunctiva, congestion in the conjunctiva of the eye and conjunctiva. Some patients had mild or no flu symptoms. Influenza B infection in children is often characterized by vomiting, abdominal pain and diarrhea. There are no complications, and the fever gradually subsides after 3 to 4 days of onset, and the systemic symptoms improve, but cough and physical strength often take a long time to recover.
Although the prominent manifestations of influenza are fever, headache, and myalgia, these symptoms can also be seen in other virus infections such as new coronavirus . It is difficult for the public to accurately identify influenza based solely on symptoms. And the epidemiological history of plus symptoms helps to identify influenza early. After influenza virus infection and new coronavirus infection, there are corresponding epidemiological history.Patients with influenza often have contacted other influenza patients before onset, or have clustered cases of influenza in their work, study or living environment.
If flu-like symptoms occur, you need to seek medical attention in time. Doctors use epidemiological history, clinical manifestations and etiology examinations to diagnose the diagnosis. The most intuitive basis is viral antigen detection and viral nucleic acid detection.
virus antigen detection is done by collecting blood samples for testing. The results are fast, but the sensitivity is low, far lower than nucleic acid detection . If the antigen test result is positive, it can be judged as a confirmed influenza patient, but if the result is negative, influenza virus infection cannot be ruled out. Viral nucleic acid detection is detected through respiratory specimens (nasal swabs, pharyngeal swabs, , nasopharyngeal or tracheal extracts, sputum). It has high sensitivity and specificity, and can distinguish virus types and subtypes. H1N1 and H3N2 were completed through this detection.
What to do after infection
After confirming that influenza virus is infected, don’t panic or anxious. A few patients need to be hospitalized for complications, and most infected people can recover within one week.
Influenza treatment includes antiviral treatment, symptomatic treatment (such as antipyretic), treatment of complications, etc. Some types of influenza viruses have targeted antiviral drugs (such as oseltamivir ), and antiviral treatment is usually 5 days. Not all cases require antiviral treatment, and the drug has a certain proportion of the incidence of adverse reactions and should be used under the guidance of a doctor. Doctors will adopt different treatment plans according to the severity of the condition.
After being infected with the virus, be careful to avoid cross-infection among family members. This requires isolation of infected people as much as possible (such as living in a separate room, not eating with other members of the family, etc.), daily cleaning and disinfection, washing hands frequently, and strengthening ventilation.
There are ways to prevent influenza
Get influenza vaccination, which is one of the most effective ways to prevent influenza by scientifically proven. It is recommended that those who are willing to receive influenza vaccine at or above and who do not have contraindications can make an appointment to receive influenza vaccine, especially key groups such as the elderly, children, pregnant women, patients with chronic diseases, family members of babies under 6 months of age and caregivers.
Then now, tomorrow, will I get the flu vaccine immediately be effective in preventing the flu this summer?
It takes about 14 days to produce antibodies after influenza vaccination. If you haven't received the flu vaccine, it is recommended to get it as early as possible. It is routinely recommended to receive influenza vaccination from September to November every year, because this period of vaccination can better cover the prevention of influenza in the second winter, spring and summer.
In addition, the following details should be paid attention to when preventing influenza:
☆ Keep the environment ventilated. If you need to close doors and windows due to weather reasons, you can open the windows regularly for ventilation, and the ventilation time is recommended not less than 30 minutes.
☆When the flu is prevalent, try to avoid crowded closed places. For example, in crowded places or people with flu-like symptoms around you, you should wear a mask that can prevent droplets (such as disposable medical masks), and the mask should cover your nose and mouth at the same time.
☆ Develop good personal hygiene habits. Wash your hands frequently, avoid touching your eyes (such as rubbing your eyes), nose (such as picking your nose) and mouth (such as picking your teeth), pay attention to coughing etiquette (when coughing or sneezing, you bend your upper arm over to cover your mouth and nose with your upper arm or cover your tissues), and avoid covering your hands, because forgetting to hygiene after covering it is common.
☆ Ensure adequate sleep, avoid anxiety, eat a reasonable diet, balance nutrition, strengthen exercise, and enhance your own resistance.
Author: Infectious Disease Center of West China Hospital, Sichuan University
Zong Zhiyong
Hospital Infection Management Department Wang Yantong
Review: National Health Science Popularization Expert Database Expert
Department of Respiratory and Critical Care Medicine, Sichuan University West China Hospital,
Chief Physician Liang Zong'an
Planning: Wu Weihong Tan Jia
Editor: Luan Zhaolin
This article comes from [Healthy China] and only represents the author's views. National Party Media Information Public Platform provides information release and dissemination services.
ID: jrtt
