Winter flu, pneumonia is coming, these knowledge please check!
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With the frequent "arrival" of cold air, the influenza virus that ravages the human world every year in the cold season has begun a new journey. Influenza virus activity develops over time, especially in the Northern Hemisphere, and generally begins in late October and peaks in January. Several influenza pandemics over the years and annual seasonal influenza epidemics have always threatened human health. To this day, influenza remains a major challenge to global public health efforts. It is worth noting that this autumn and winter, the risk of superimposed epidemics of respiratory infectious diseases such as the new crown epidemic and influenza still exists, so it is urgent to do a good job in the prevention and control of respiratory infectious diseases.
So why is the flu so terrible?
How do we distinguish between the common cold, flu and COVID-19?
What does it have to do with pneumococcal bacteria?
Recently, at the "Health Science Popularization Cloud Lecture Hall" sponsored by the Chinese Preventive Medicine Association and co-organized by the Health Times Newspaper, Science and Technology China, and the Home of Science and Technology Workers, Lu Lian, chief physician of the Department of Infectious Diseases of Beijing Ditan Hospital affiliated to Capital Medical University and an advanced individual in the national fight against the new crown pneumonia epidemic, answered various questions about influenza and pneumonia in detail.
Persistent fever and soreness
Fever clinics should be visited as soon as possible
Although they are all called colds, influenza is much more lethal than the common cold, which is an acute respiratory infectious disease caused by influenza virus infection. Compared with the common cold, the flu is not only acute, contagious, but also more severe.
Lu Lian pointed out that the upper respiratory symptoms of the common cold are more obvious, while the systemic symptoms such as muscle soreness and fatigue caused by the flu are more serious. The common cold can heal itself in about 7 days and rarely has complications; although most of the flu is self-limiting, some of them can be combined with complications such as pneumonia, otitis media, myocarditis, and meningitis.
Globally, influenza can cause 3 to 5 million severe cases and 290,000 to 650,000 deaths from respiratory-related diseases worldwide, according to data released by the World Health Organization.
In the autumn and winter of this year, there have been local cases of new crown pneumonia in some parts of China, and some areas have had local clusters of epidemics, with a large number of cases in a short period of time. Coupled with the cold weather, the situation of epidemic prevention and control is still grim. Influenza and COVID-19 are respiratory infectious diseases with similarities in the signs, symptoms, and modes of transmission. Now many people have fever, cough is also very nervous, dare not go to the hospital.
Lu jointly reminded that ordinary people generally cannot distinguish between influenza and new crown pneumonia on their own, and when symptoms such as persistent high fever and body aches occur, they should go to the fever clinic as soon as possible to check for new crown pneumonia. If laboratory tests confirm that influenza is confirmed, antiviral drugs (such as oseltamivir) can be taken within 48 hours.
Influenza viruses love to mutate
Live poultry are best treated with less contact
Influenza viruses belong to the orthogonal myxovirus family, which can be divided into A, B, C and D types according to the matrix protein (M) and nuclear protein (NP) of the virus, of which the influenza A virus has the greatest impact on humans. How to understand the H1N1, H2N2, etc. that we often hear? Lu explained that H and N are the code for the glycoprotein (protein), the two constituents of the influenza A virus, which represent hemagglutinin (H) and neuraminidase (N), respectively. A total of 18 subtypes of H (H1-H18) and 11 subtypes of N (N1-N11) have been found, and they can form a variety of combinations. Among them, only the H1-H3 and N1-N2 subtypes can be sustained and effectively transmitted in humans, also known as human influenza viruses. Other subtypes are referred to as avian influenza viruses or swine influenza viruses, depending on the host. After some viruses mutate, they may also infect people across hosts.
"If H and N are the key to the door, sialic acid is the lock."
Lu Lian vividly compared that after the avian influenza virus invades the human body, it mainly binds to sialic acid and enters the cells. Influenza viruses are highly variable, that is, the key will change, and seasonal influenza A strains with animal influenza viruses may appear after they are recombined with animal influenza viruses.
The main sources of infection of avian influenza are poultry carrying viruses, such as chickens, ducks and geese, and other birds such as quails, pigeons, and wild birds. Live poultry markets and infected poultry are the main sources of avian influenza infection in our country.
Lu jointly reminded that quarantined poultry products should be purchased as much as possible in regular sales places, unnecessary contact with poultry should be reduced as much as possible, and live poultry should be carefully contacted in the wild, and birds or their feces should be contacted, and attention should be paid to thoroughly cleaning hands.
The flu vaccine needs to be given year after year
Egg allergy is no longer contraindicated
The World Health Organization and national authorities believe that annual influenza vaccination is the most effective way to prevent influenza, but there are many doubts about influenza vaccination among the public.
Like what
Does the flu vaccine take effect immediately?
Can people with egg allergies beat it?
Is it safe for pregnant women to play?
Lu lianhe explained that after vaccination, it usually takes 2 to 4 weeks to produce antibodies with protective levels, so if the vaccinated person is infected with the flu virus during this time, they may still develop the flu.
To better prevent influenza, influenza vaccines should be given before the start of the annual flu season to give the immune system enough time to build up protective antibodies. In addition, a flu vaccine does not mean a lifetime benefit, because the virus that causes influenza is different every year, and experts from the World Health Organization (WHO) will predict the type of influenza virus according to the situation of the year, and the manufacturer will prepare it. Therefore, the flu vaccine needs to be given every year.
Most flu vaccines are produced from chicken embryos, and because of this, influenza vaccines were once banned for people with egg allergies. To this day, many people still believe that people who are allergic to eggs cannot get the flu vaccine. As vaccine production processes improve, there is growing evidence that influenza vaccines are safe for people with egg allergies. The Pharmacopoeia of the People's Republic of China (2015 edition and 2020 edition) does not make people allergic to eggs a contraindication. The pharmacopoeia stipulates that the ovalbumin content in the influenza vaccine should not be higher than 500 ng/ml, and the egg protein content in the current vaccine has been greatly lower than the national standard, and those who are allergic to eggs can also be vaccinated against influenza.
Numerous studies confirm that pregnant women have a higher risk of severe illness, death and adverse pregnancy outcomes after influenza. Influenza vaccination by pregnant women at any stage of pregnancy has sufficient evidence to prove its safety, and antibodies can be passed to the fetus after vaccination, and the protective effect on infants under 6 months of age is clear.
Influenza vaccine and COVID-19 vaccine
The interval between vaccinations should be greater than 14 days
Lu Lian stressed that the elderly, children, pregnant women, patients with chronic underlying diseases and immunodeficiency people are at high risk of influenza and high-risk groups of severe cases. People over 6 months of age can be vaccinated if there are no contraindications. For small babies under 6 months of age, the vaccination of people who come into contact with the child's surroundings, especially family members and caregivers, also has a certain protective effect on the influenza of children under 6 months of age.
Children's immune function is relatively low, more likely than adults to be infected with influenza, and it is easy to induce a variety of serious complications. More than 90% of the annual influenza outbreaks reported in china occur in schools and childcare facilities. Therefore, it is necessary for children to get a flu vaccine. At present, the vaccination of minors against the new crown virus in many parts of the country is also in progress. According to the recommendations of China's "Technical Guidelines for Covid-19 Vaccination (First Edition)", the interval between influenza vaccine and covid-19 vaccination should be greater than 14 days.
Every year during the flu season is the peak of heart disease, because the flu virus can cause inflammation in the body and make the heart disease worse. Influenza vaccination can also prevent the onset of cardiovascular disease and reduce the risk of influenza complications in patients with cardiovascular disease. In the American College of Cardiology and the American Heart Association's guidelines for secondary prevention of coronary heart disease, a scientific recommendation was published, namely "influenza vaccine as a secondary prevention of cardiovascular disease."
It is worth noting that when receiving influenza vaccines, it is also necessary to strictly follow the various measures for epidemic prevention and control, go to the vaccination according to the time period arranged by the vaccination clinic, reduce the number of accompanying personnel, and avoid staying in places where people gather. At the same time, we will cooperate with the epidemic prevention measures of "appointment system, wearing masks, one meter line, and frequent hand washing" to jointly maintain a safe environment for vaccination.
Influenza viruses are highly variable and uncertain, which makes influenza prevention and control a series of challenges. For individuals, vaccines are an important means of preventing diseases, allowing us to turn passive into proactive in the face of the threat of infectious diseases. In addition to vaccination, maintaining good living habits and protective measures can also effectively reduce the infection and transmission of influenza and pneumonia.
According to the clinical experience of Lu Lianhe, the overall number of influenza patients in the past two years has decreased significantly compared with the same period in previous years. The reason may be that in the process of fighting the new crown pneumonia epidemic, people's awareness of protection has strengthened.
First, the general wearing of masks and less gathering reduces the chance of virus spread;
The second is to wash hands frequently and disinfect frequently, reducing the chances of virus survival.
Therefore, I still hope that everyone can maintain such hygiene habits in the future.
When the flu meets pneumococcal bacteria
Destructive force "1+1>2"
In addition to preventing influenza, there is also another major type of disease that should be vigilant, that is, pneumococcal disease. Because it is the most common pathogenic bacteria for influenza co-infection, when the two are combined, they can have a destructive force of "1+1>2" on human health. Severe cases of influenza often occur with pneumonia, especially in infants, young children, the elderly, and people with chronic underlying diseases. Pneumococcal disease is an important cause of death in children under 5 years of age, according to a study published in 2018, about 294,000 children under 5 years of age die from pneumococcal infection worldwide, and about one child under 5 years old dies of pneumococcal worldwide.
Lu Lian pointed out that pneumococcus is also widely present in healthy people, it can colonize the nasopharynx of people, and it will not cause disease in healthy conditions. But once they encounter a cold or a decline in resistance, they will take the opportunity to become active, and when the bacteria multiply to a certain extent, it will cause pneumonia.
Pneumococcus can also enter the blood circulation, causing multi-organ infections throughout the body and even sepsis. With the widespread use of antibiotics, antibiotics that were previously effective against pneumococcal bacteria are also facing increasingly serious drug resistance problems. Therefore, for pneumococcal disease, prevention is more important than treatment. Thankfully, pneumococcus also has a vaccine to prevent it. Pneumococcal diseases are also classified by the WHO as "very high priority" diseases prevented with vaccines.
Frequent colds, or respiratory tract
Syncytial virus "trick-or-treating"
In the vast army of respiratory infection pathogens, in addition to the flu, new coronavirus, and pneumococcal bacteria just mentioned, there is another one that cannot be ignored, that is, respiratory syncytial virus. Because it causes adjacent cell fusion during cell culture, cell lesions form a syncytial structure, which is called respiratory syncytial virus, and the winter and early spring seasons of each year are the epidemic seasons of respiratory syncytial virus.
When it comes to respiratory syncytial virus, many people may feel very strange, but in fact, this virus is not far away from us.
Lu pointed out that children under 2 years of age are basically infected with respiratory syncytial virus. Respiratory syncytial virus is a common seasonal infectious disease virus that causes respiratory tract infections, is the primary pathogen of lower respiratory tract infections in infants and young children, some children will be repeatedly infected, fever, cough, runny nose and other cold symptoms, when the infection is serious, there are lung and systemic symptoms.
So far, no vaccine has been developed against respiratory syncytial virus, and daily prevention is important, especially hand hygiene. High-frequency contact areas, such as doorknobs, children's toys, etc., are best to wipe and disinfect them with alcohol frequently.
Text || Fan Hongbo
Edit || Wan Tao
The duty director || Fan Hongbo