Is there any sequelae of the flu? Teach you how to stay away from the "long flu"

In the past month or two, many people have experienced a fever, headache, sore throat, cough...... There are even people who have gone through more than one round!

Recently, "The first stream just hit the second stream again" was once on the hot search. Some people say that they have detected influenza A, influenza B and mycoplasma infection at the same time......

What is Stream B and what is the difference between Stream A and Stream A?

If you get stream A, will you still get stream B?

After the flu is cured, are there any "sequelae"?

Let's take a look today.

Influenza viruses that can infect humans are mainly divided into four categories: A, B, C, and D.

Among them, the most susceptible and common is influenza A virus (influenza A), with the main circulating strains being H1N1 and H3N2.

There are two main subtypes of influenza B viruses (influenza B), Victoria and Yamagata, which can also cause infections and epidemics.

The flu vaccine we get is against these major strains.

Influenza C and D viruses generally do not cause seasonal epidemics.

According to the latest issue of the National Influenza Center's Weekly Influenza Surveillance Report[1]:

1. The upward trend of the influenza epidemic in the country has been contained, and some areas have begun to decline;

2. The proportion of influenza A (H3N2 strains), which used to dominate transmission, began to decline;

3. The proportion of influenza B (influenza B) continues to rise - the proportion of influenza B in the southern region is 18.7%, while the proportion in the northern region is as high as 35.2%!

(Proportion of "influenza B" to all flu-positive cases in the last weeks of 2023)

Yes, possible!

Influenza A and Influenza B, although both belong to the family of influenza viruses, they are different types. Due to the differences in antigenicity of strains, the production of antibodies after infection with different strains is almost impossible to neutralize with each other.

In other words, the antibodies produced by the body after infection with influenza A are not effective in preventing influenza A, and vice versa.

Even influenza A viruses may be reinfected with H3N2 after recovery from H1N1 infection.

Therefore, it is entirely possible for a person (especially the elderly and children with weakened immunity) to get the flu multiple times in a year or even half a year.

The symptoms of influenza A and influenza B are not very different, and it is generally difficult to distinguish them based on clinical presentation alone.

It can also cause high fever (39°C~40°C), chills, headache, body aches, fatigue, loss of appetite, etc., and may also cause symptoms such as sore throat, dry cough, vomiting and diarrhea [2]. Clinically, there is no big difference between conventional drug treatment regimens.

However, the recovery time varies from person to person. Some people take medicine and get better within a week, while others take two weeks or even longer to get better.

But at the end of the day, influenza is still an acute viral infection.

Regardless of influenza A or influenza B, people with normal immune function can generally recover completely without leaving long-term sequelae.

However, some "vulnerable" populations (eg, the elderly, pregnant women, and patients with chronic diseases) can be life-threatening if they are complicated by severe diseases such as pneumonia, myocarditis, and encephalitis after getting influenza [3].

These complications can lead to interstitial lung lesions, pulmonary fibrosis, cardiac insufficiency, and long-term symptoms such as decreased physical strength, fatigue, and chest tightness after exertion (commonly known as "sequelae") [4].

A foreign study showed that the cumulative incidence of angina, tachycardia, type I diabetes, cough, hypoxemia, and shortness of breath increased in the year and a half after receiving influenza [5].

However, these "sequelae of influenza" are much less harmful to all systems of the body than "post-COVID sequelae".

To avoid getting the flu multiple times, and to stay away from the "sequelae" of the flu as much as possible, it is best to do the following four things.

First of all, it is still said countless times - vaccination!

Influenza vaccine, which protects against both influenza A and influenza B, is the most effective means of preventing influenza and can significantly reduce the risk of serious complications.

According to the Technical Guidelines for Influenza Vaccination in China, the following individuals should be given "priority" to receive influenza vaccines [3]:

Medical personnel, including clinical treatment personnel, public health personnel, health quarantine personnel, etc.;

Seniors aged 60 years and older;

People with one or more chronic diseases;

Vulnerable populations and employees in elderly care institutions, long-term care institutions, welfare homes and other crowd gathering places;

Pregnant woman;

Children aged 6 to 59 months;

family members and caregivers of infants under 6 months of age;

Groups of people in key places such as childcare institutions, primary and secondary schools, and supervision sites;

Even if you get the flu despite getting the flu vaccine, you generally have milder symptoms and recover more quickly [3].

Second, do a good job of protection.

During this season, it is still recommended to avoid crowded or closed places.

Try not to have close contact with people who have the flu or who are already showing obvious symptoms of illness.

You still have to wear a mask when you go to shopping malls, hospitals, etc. Wash your hands well after going out and returning home every day, and open the windows indoors for ventilation at least twice a day.

Third, improve immunity.

For example, eat a healthy diet, exercise moderately, get enough sleep, and maintain a good attitude.

Stronger immunity reduces the risk of infection, and even if you are infected, you usually don't develop severe disease.

Finally, seek medical attention in time and standardize treatment.

Once you have the flu-like symptoms mentioned above, it is best to rest at home, conduct health observation, and go to work and class without illness.

And under the guidance of a doctor, early diagnosis and early use of influenza antiviral drugs.

May everyone be free from the flu and live a healthy life!

Audit expert: Jiang Weimin

Chief physician of the Department of Infectious Diseases, Huashan Hospital, Fudan University

bibliography

[1]https://ivdc.chinacdc.cn/cnic/zyzx/lgzb/202312/P020231228345076862378.pdf

[2] Influenza Diagnosis and Treatment Plan (2020 Edition), General Office of the National Health Commission, 2020.

[3] Technical Guidelines for Influenza Vaccine Vaccination in China (2023-2024).

[4] Iuliano, Danielle A ,Roguski,et al. Estimates of global seasonal influenza-associated respiratory mortality: a modelling study[J]. LANCET.2018.

[5] Long-term outcomes following hospital admission for COVID-19 versus seasonal influenza: a cohort study. The Lancet Infectious Diseases. Dec.14,2023. DOI:https://doi.org/10.1016/S1473-3099(23)00684-9

*Produced by the Tencent Medical Dictionary content team