Recently, there has been a high incidence of influenza. According to the latest data from the Chinese Center for Disease Control and Prevention, the positive rate of influenza viruses continues to rise, and more than 99% of them are influenza A. Experts remind: In addition to children and people with chronic underlying diseases, young and middle-aged people should not take it lightly. Multiple disease protection agencies have issued influenza health warnings, reminding residents everywhere to pay attention to protecting themselves and their families.
Image source: Summary of influenza epidemic situation in China (as of December 29, 2024)
So, what exactly is influenza A? What are the symptoms after infection? Why do many patients feel pain all over their bodies? How to prevent it? Today’s article explains it clearly.
What is influenza A?
Influenza virus, as its name suggests, is a virus that belongs to the Myxoviridae family. It has four subtypes, and influenza A is one of them:
·Type A (Type A):
It is prone to mutation, fights across species (humans and animals), and has caused many worldwide pandemics.
· Type B (Type B):
Influenza B can also cause seasonal epidemics and usually only affects humans.
·Type C (Type C):
It can infect humans, dogs, and pigs, only causes sporadic cases of upper respiratory tract infection, and generally does not cause epidemics.
· Type D (Type D):
It mainly infects pigs and cattle, and has not been found to infect humans. .
There are four different subtypes of influenza viruses, A, B, C, and D, of which A and B are the most common. Influenza A viruses are divided into multiple subtypes, and these subtypes are determined by two surface proteins of the virus: hemagglutinin (HA) and neuraminidase (NA). Currently, 18 types of hemagglutinin (HA) and 11 types of neuraminidase (NA) have been discovered.Different combinations can constitute different virus subtypes. The familiar H1N1 and H3N2 subtypes are the pathogens that once caused serious epidemics.
Influenza is familiar to everyone. In the north, there is an epidemic every winter and spring. In the south, due to climate problems, there may be epidemic cases throughout the year.
Headache, stomachache, joint pain...
Why does influenza A infection hurt so much?
After influenza infection, most people will develop obvious symptoms. The most typical one is of course fever, and the general body temperature can reach 39~40℃. High fever often causes patients to experience chills and chills.
In addition, some people may experience general discomfort such as fatigue and loss of appetite, accompanied by respiratory symptoms such as cough, runny nose or nasal congestion. Some patients may have gastrointestinal reactions such as nausea, vomiting and diarrhea.
But when it comes to influenza A, the most impressive thing is the pain! It hurts so much! Not only may there be throat pain, headache, muscle pain, joint pain...Some people describe that having H1N1 infection feels like every part of the body is being twisted up like a towel, and every inch of the body is painfully tortured!
Why does influenza A cause so much pain? This can be said to be "unjustly accused" of the influenza A virus, but not entirely unjust.
Because the pain is not directly caused by the influenza A virus, but when the human body is infected by the virus, it will produce an immune response and release antibodies to attack the virus and prevent further spread of the virus. These proteins not only prevent the spread of viruses in the body, but also cause an inflammatory response in the body. Inflammation is the main cause of pain.When inflammation occurs, white blood cells produce cytokines (small proteins used in cell signaling), which can cause inflammation in muscles and joints and, as a result, significant pain.
The pain itself can certainly be unbearable, but the good news is that most pain can be relieved by taking NSAIDs such as ibuprofen.
The most worrying ones are high-risk groups such as infants, pregnant women, the elderly and patients with chronic diseases. They are at a higher risk of severe complications, and their condition may deteriorate rapidly, with persistent high fever reaching over 39°C, and may develop into acute respiratory distress syndrome (ARDS), sepsis, septic shock, heart failure, renal failure, and even multiple organ dysfunction.
How to prevent it?
Is it still too late to get a flu shot?
When facing the challenge of influenza, it is important to know that “prevention is better than cure.”The best ways to prevent the flu:Get vaccinated! Get vaccinated! Get vaccinated! Get vaccinated...
Although it is recommended to complete the flu vaccination before the end of October, it is already more than January, so will it be too late to get vaccinated now?
Although it's a little late, I still recommend going now.The main reason is that the epidemic peak of influenza is usually concentrated from the end of November to February of the following year, and this year's influenza peak is delayed compared with previous years. We all don’t know when we might get the flu, so getting vaccinated now may prevent you from getting infected in the future, so getting vaccinated can still play a protective role.
Of course, the earlier you get vaccinated, the better the protection. Even if you get vaccinated now, you can reduce the risk of catching the flu.Vaccination can effectively reduce the chance of infection and reduce the likelihood of serious complications. No matter when you get vaccinated, it is safer to have protection than no protection.
So if you are already infected this year, do you still need to get vaccinated again?
Importantly, although influenza A infection is now the mainstream, in fact, multiple influenza virus strains circulate at the same time every year, and it is difficult for scientists to accurately predict which strains will be dominant.Even if you've had the flu this year, you may still be protected from the virus if you didn't get a flu shot this year.
There are three main types of vaccines currently available:
·live attenuated influenza vaccine: Quick onset, long-lasting protection, less pain
·Inactivated Influenza (Subunit) Vaccine: There are few adverse reactions and you can get it without any money.
·Inactivated (split) influenza vaccine：High quality, low price and high cost performance
No matter which vaccine is used, the most important thing is: get it in time!
Just take oseltamivir or
Is Mabaloxavir good for you?
Oseltamivir and mabaloxavir are indeed effective antiviral drugs currently used to treat influenza. Their main function is to reduce symptoms and shorten the course of the disease by inhibiting the replication of influenza viruses. However, taking these drugs alone does not guarantee full recovery in all patients, especially in severely ill or high-risk groups.
Characteristics of these two drugs:
·Oseltamivir:Suitable for children and adults aged 1 year and above, it needs to be taken twice a day for 5 consecutive days. It is characterized by a wide range of uses, including children of a young age. Studies have shown that treatment with oseltamivir can stop viral replication and shedding within approximately 75 hours.
·Mabalosavir:It is suitable for children and adults aged 5 and above. Its biggest feature is that it only needs to be taken once. This is especially convenient for patients who are unwilling to take medication for a long time or who have difficulty taking medication. Research shows that mabaloxavir can quickly stop viral replication and shedding within 24 hours.
The main functions of these two antiviral drugs are to relieve symptoms and shorten the course of the disease.But the virus cannot be completely eliminated, and the efficacy varies depending on the severity of the condition and the timing of taking the medication.The best time to use is within 48 hours of the onset of symptoms.
In addition to taking antiviral medications, people with the flu should take the following steps to promote recovery:
·Get enough rest: The flu can cause general weakness and fatigue, and rest helps the body better fight the virus.
·Replenish fluids: Influenza is often accompanied by fever and sweating. Replenishing fluids can help avoid dehydration.
·Symptomatic treatment: Antipyretic and analgesics can be used under the guidance of a doctor to relieve symptoms such as fever, headache and muscle soreness.
·Prevent secondary infection: Patients should avoid contact with other people to reduce the possibility of cross-infection, while wearing masks, maintaining personal hygiene and staying at home.
References
[1]https://www.chinacdc.cn/jksj/jksj04_14249/202501/P020250102412903696017.pdf
[2]https://www.health.harvard.edu/diseases-and-conditions/why-does-the-flu-cause-body-aches
[3]https://news.llu.edu/health-wellness/why-do-muscles-joints-ache-during-flu
[4]https://www.hopkinsmedicine.org/-/media/files/health/11flumythsinfographic.pdf