Winter and spring alternate, the recent Shanghai has experienced "winter and summer" two days, the emergency volume of the hospital door has quietly increased, and there are more and more companions with cold and fever around, everyone is concerned about whether they have the legendary "A flow"? How to protect yourself during this special "flu" season? Let's make it clear.
What is Flu A?
In 1918~1920, a cold swept the world, estimated that 1 billion people were infected, 20 million ~ 40 million people died, and even the then Spanish king could not afford to be sick. This is the famous Spanish flu, and it is also the first time that influenza has appeared on the stage of history.
Source: Sohu
What we call influenza A today is the abbreviation of influenza A, which is a class of diseases caused by influenza A virus. Human influenza virus is an RNA virus, belonging to the orthomyxoviridae family, which is divided into four types A (A), B (B), C (C), and D (D) according to the anti-prototype, of which influenza A virus is prone to mutation.
Influenza A is prone to mutations, and when small mutations occur, antigenic drift forms, causing seasonal outbreaks. When the virus genetically recombines this large mutation to produce a new strain, it will take advantage of the general lack of immunity in the population and break out a worldwide pandemic. Influenza B and C viruses are not easily mutated, and these two types rarely cause large-scale epidemics, and D is only circulating among animals.
Influenza virus structure and mutation characteristics Source: Bio Online
The mainland influenza surveillance network shows that the current influenza in the southern part of the mainland is at a high incidence in the same period, and the increase in influenza-like cases is more than twice that of 2019, and it is still in the stage of rapid rise.
Among the influenza-like cases, the main monitored strains were influenza A(H1N1), A(H3N2) subtypes, and a small number of influenza B, and no other new mutants were detected.
What are the symptoms of the flu?
The incubation period of influenza is 1-3 days, typical clinical manifestations are fever, chills, headache, general malaise, and "flu-like" symptoms such as cough, sore throat, runny nose, among which systemic symptoms are more prominent and more serious (such as body aches, fatigue, loss of appetite, etc.), body temperature often exceeds 39 °C, other viruses such as new coronavirus infection are similar, clinically often difficult to identify.
Severe cases can also develop a variety of complications such as viral pneumonia, secondary bacterial pneumonia, and acute respiratory distress syndrome, especially in children, the elderly, and people with other underlying medical conditions.
Differentiation of A Flu from Other Common Respiratory Diseases|Authorship
How do I know if I have the flu?
Like the new crown, the way to accurately identify whether infected with influenza is to carry out etiological testing, mainly using the following two methods: first, virus antigen detection, which is also a commonly used detection method in hospitals at present, with fast characteristics, positive supports influenza diagnosis, but negative can not completely exclude influenza; The second is viral nucleic acid detection, which has the advantages of high sensitivity and distinguishing between virus types and subtypes.
For patients with fever, body aches and other similar "flu-like" symptoms, everyone will be entangled in whether it is necessary to carry out influenza testing, in fact, there is no need to be nervous, mainly for fever, body aches and other symptoms to deal with, doctors will also give corresponding antiviral treatment according to the actual situation.
Identification of common "colds"|authorship
What should I do if I have the flu?
Influenza is a self-limiting disease that gradually resolves after 3-5 days of onset without being overly stressed. "Drink more hot water" is not only a comforting word, but also can help everyone improve dry throat symptoms and reduce dehydration during influenza fever.
Eat lightly, rest at home, closely observe the changes in the condition, if symptoms worsen, please go to the hospital in time to seek medical help. During the period at home, it is also necessary to protect yourself and isolate appropriately to reduce the spread of influenza among family members.
Source: Douban
How is influenza treated?
Treatment of the cause - antiviral
At present, the most commonly used antiviral drug is oseltamivir, which is a class of neuraminidase inhibitors that can prevent the release and spread of viral particles, zanamivir and peramivir have similar effects; Arbidol acts on the hemagglutinase target of influenza virus and inhibits the fusion of influenza virus lipid membrane with human cells; Mabaloxavir is an RNA polymerase inhibitor, and these antiviral drugs can block viral replication, so they can generally be used within 48 hours of onset to achieve good efficacy.
Schematic diagram of oseltamivir antiviral Source: Zhihu
Symptomatic treatment
Common ibuprofen, acetamidofen and other antipyretic and analgesic drugs on the market can effectively help everyone reduce fever and reduce systemic symptoms, but aspirin is contraindicated in children; Compound cold medicine can also relieve nasal congestion, runny nose, sore throat and other discomfort; Cough drugs can also dissolve phlegm and suppress cough; Traditional Chinese medicine also has a very good effect, and it must be used strictly according to the instructions.
Table of commonly used drugs (for reference only) Source: CCTV News
How can I prevent Flu A?
Influenza is a common infectious disease, and its R0 value (that is, one patient can infect at most several susceptible individuals) is between 1-2, which is much lower than the new crown Omicron strain, so there is no need to panic excessively.
Influenza infectivity|Source: http://i.kinja-img.com/gawker-media/image/upload/t_original/hptm6ebnfpwdnxj1o5dy.png
Doing a good job of "three pieces, five also" is still an effective way to prevent influenza. When flu-like symptoms occur, you should pay attention to rest and self-isolation, do not bring illness to work, school, go to public places, and wear a mask on the way out for medical treatment.
Source: Shanghai release
For children, the elderly or high-risk groups with underlying diseases, annual influenza vaccination is the most effective means of prevention, influenza virus is prone to mutation, the World Health Organization will monitor the virus mutation, update the vaccine components, targeted vaccination, to protect susceptible people.
Generally, sufficient antibodies will be produced 2-4 weeks after influenza vaccination, and the protection period is maintained at 6-8 months, and vaccination before the arrival of the influenza season every year can effectively protect the population.
Source: Sohu
Spring is about to bloom, and the flu will eventually pass, protect yourself and your family, and work together to spend the flu season.
The author of this article: Zhu Linjun, deputy chief physician of the Department of Respiratory and Critical Care Medicine, Shanghai Putuo District Central Hospital.
Responsible Editor: Little Dandelion
Cover image source: Sohu
Bibliography:
[1]http://rspb.royalsocietypublishing.org/content/277/1689/1857
[2] China Influenza Surveillance Report.9 week of 2023