Flu is coming! Knowing the symptoms of flu and how to prevent it is important!

Influenza, the full name of which is influenza, is an acute respiratory infectious disease caused by influenza virus. Most cases are self-limiting and can heal on their own without special treatment, but some patients may develop severe influenza due to serious complications such as pneumonia, and a small number of patients may die from acute respiratory distress syndrome (ARDS) and multiple organ failure.

Throughout history, there have been many influenza pandemics around the world, resulting in many deaths. For example, the "Spanish Flu" of 1918-1919 caused the deaths of at least 50 million people and had extremely serious negative impacts on social and economic development.

Influenza is particularly prevalent in winter and spring. With the recent cooler weather, influenza has entered its epidemic period. Therefore, understanding and preventing influenza is of great significance to social and economic development and protecting physical health.

Recognize the symptoms of flu

Influenza usually has an acute onset, with symptoms such as fever (above 38°C, and in some cases up to 40°C), chills, chills, dizziness, headache, muscle and joint pains, fatigue and loss of appetite. Some cases are accompanied by sore throat, cough, nasal congestion, runny nose, flushed face, conjunctival congestion, etc., and vomiting and diarrhea may occasionally occur.

Symptoms of mild influenza are often similar to those of the common cold, but the fever and systemic symptoms are more severe. Severe cases may develop viral pneumonia, secondary bacterial pneumonia, acute respiratory distress syndrome, shock, disseminated intravascular coagulation (DIC), cardiovascular and nervous system and other extrapulmonary manifestations and multiple complications, and even death.

Children under 5 years old, the elderly (especially those with chronic diseases), and people with weakened immune systems (such as those infected with HIV) are more likely to develop serious complications and have a worse prognosis.

How influenza is spread

Influenza is highly contagious and is mainly transmitted through the respiratory tract , but can also be transmitted through contact .

Droplet transmission: Influenza patients and latently infected people spread influenza viruses through respiratory secretions (such as droplets, saliva, etc.). When patients speak loudly, cough or sneeze, droplets containing the virus are produced. Susceptible people may be infected with influenza by inhaling these droplets or coming into direct contact with the respiratory secretions of infected people.

Aerosol transmission: In a relatively closed environment with poor air circulation, some small particles in the droplets exhaled by the infected person can form aerosols in the air and float in the air for a long time. Susceptible people may also be infected by inhaling these aerosols.

Contact transmission: You may also be infected with the influenza virus by touching objects contaminated with the influenza virus, such as door handles, stair railings, etc., or by touching the mucous membranes of the mouth, nose, eyes and other organs with your hands.

Influenza virus detection

Laboratory pathogen detection is the main method for detecting influenza viruses and is also the "gold standard" for confirming influenza. There are four types of pathogen detection, namely:

Virus isolation: Inoculate the patient's gargle or upper respiratory tract secretions within three days of onset into chicken embryos or tissue culture for virus isolation;

Nucleic acid testing, using common reverse transcription polymerase chain reaction (RT-PCR) to directly detect viral RNA in the patient's upper respiratory tract secretions, is the most commonly used method because it is rapid, sensitive, and specific;

Serological examination measures antibodies. Serum from the acute and convalescent phases is collected for complement fixation test or hemagglutination inhibition test. A 4-fold increase in antibody titer is considered positive.

Antigens are detected by immunofluorescence method, and inclusion bodies are detected by nasal mucosal smear staining within 3 days of onset. Antigen detection by fluorescent antibody may be positive.

If typical symptoms of influenza appear, you can go to the hospital on your own (children or the elderly accompanied by relatives) for influenza virus nucleic acid testing to confirm the diagnosis.

Treatment of influenza

Generally speaking, most cases can heal themselves without special treatment, while a small number of cases can be treated with antiviral treatment and symptomatic supportive treatment.

Antiviral drugs: For the treatment of influenza virus, commonly used antiviral drugs include oseltamivir (Tamiflu) and zanamivir (Relenza), which can alleviate symptoms and shorten the course of the disease by inhibiting viral replication. It should be noted that antiviral drugs must be used at the early stage of viral infection to achieve the best effect.

Symptomatic treatment: Although antiviral drugs are the key to treating influenza, symptomatic treatment is also very important. Patients should ensure adequate water intake, proper rest, and follow the doctor's advice on antipyretic, analgesic and other treatments.

In addition to antiviral and symptomatic treatment, traditional Chinese medicine can also be used to improve the body's antiviral ability.

Flu Prevention

Although influenza is highly contagious, there are many ways to prevent it.

1. Vaccination. Flu vaccine is one of the most effective ways to prevent flu. The vaccine contains three or four (trivalent or quadrivalent) influenza virus strains, which can stimulate the body to produce immunity. Vaccination is especially important for the elderly, children, pregnant women and people with weak immunity. Some friends may still be infected with the flu after being vaccinated. They will doubt the effectiveness of vaccination and even persuade their friends not to get vaccinated. In fact, this idea is wrong. There are nearly 200 subtypes of influenza A! The World Health Organization predicts the strains that may become popular every year, and then produces vaccines for the corresponding strains. For example, the trivalent and quadrivalent vaccines we are familiar with can only protect against a few subtypes. The subtypes that the vaccine can cover are limited, but we still need to be vaccinated, just in case the prediction is correct.

2. Personal protection measures. Maintaining good personal hygiene habits, such as washing hands frequently, wearing masks, and avoiding crowded places, can effectively reduce the risk of influenza virus infection. In addition, strengthening exercise, ensuring adequate sleep and a balanced diet can also help improve the body's immunity and prevent the occurrence of influenza. During the peak period of influenza, families should remind young children to wash their hands more often and avoid crowded places.

3. Avoid contact with the source of infection. Contact with the source of infection is one of the main ways that influenza spreads. Therefore, avoiding close contact with people who have influenza, especially during the peak period of the epidemic, can effectively reduce the risk of infection.

4. Healthy lifestyle. Maintaining a healthy lifestyle, such as quitting smoking, limiting alcohol consumption, and maintaining a good work and rest schedule, can help improve the body's immunity and prevent the invasion of influenza viruses.

5. Community prevention and control measures. Community prevention and control measures are also crucial during the peak influenza season. Strengthening disinfection of public places, providing protective equipment such as masks, and strengthening epidemic monitoring and reporting can effectively control the spread of influenza.

To sum up, we should have a full understanding of influenza prevention knowledge, do not panic, and respond scientifically!