Mycoplasma pneumonia "exits", the proportion of B-stream continues to rise, and the infusion of infected children is relatively small.
Just entering 2024, "A stream just recruited B stream" and rushed to the hot search. Since September last year, a variety of respiratory diseases have been prevalent. Nowadays, mycoplasma pneumonia, once the "dominant screen", has quietly left the scene, and the flu has entered the market in a high profile. As the proportion continues to rise, "B-stream" has become the new protagonist.
After being infected with B-stream, many people have symptoms of leg pain. In this regard, Ding Mingming, the attending physician of Pediatric Outpatient Department of Peking University People’s Hospital, said that among the children admitted, B-stream is more prone to myositis than A-stream, mainly manifested as muscle soreness, especially leg muscle soreness. For adults, Wang Yue, an attending physician in the fever clinic of the Department of Infectious Diseases, Peking University People’s Hospital, said that the incidence of myositis in patients with B-stream is not obvious, and systemic symptoms such as fever, chills, headache and joint pain are more common.
Li Li (right), deputy head nurse of pediatric outpatient department of Peking University People’s Hospital, is answering parents’ questions.
Visit: The proportion of infusion in children with influenza is lower than that of mycoplasma pneumonia.
At 1 o’clock on the afternoon of January 8, the Beijing News reporter visited the pediatric clinic in Xizhimen Campus of Peking University People’s Hospital. There are 4 consultation rooms here, including special needs and general pediatric clinics (referred to as "Pu ‘er Clinic"). In the corridor, there are some parents and children sitting sparsely, which is completely different from the scene of overcrowding and inability to walk in September last year.
"Children with mycoplasma pneumonia have a high proportion of infusions, with the daily infusion volume reaching more than 60-90, which is much higher than the previous volume (10-20). Many children still need to be atomized, and some even need to be hospitalized to’ wash their lungs’. Parents are particularly anxious. But the flu is different, because there are specific drugs, doctors can go home after prescribing drugs, and there are very few people staying in the clinic, which is not easy to cross infection. " Li Li, deputy head nurse of pediatric outpatient department of Peking University People’s Hospital, said.
"The flu may also develop into pneumonia, but the probability is not as high as that of mycoplasma infection because there are specific drugs." Ding Mingming, an attending physician in the pediatric outpatient department of Peking University People’s Hospital, said that influenza is easier to detect than mycoplasma, and there are specific drugs. Once diagnosed, as long as antiviral drugs are used in time, it is not easy to develop into a serious disease.
The scale of pediatric outpatient service in Xizhimen Hospital of Peking University People’s Hospital is not large, and the daily outpatient service is not much. Before the peak of this wave of respiratory diseases comes (before September 2023), one doctor in Puer outpatient service is enough. With the sharp increase in the number of children with respiratory tract infection since September last year, the hospital adjusted the doctor’s visits in time. At most, there were three doctors visiting the Pu ‘er clinic. At the peak of the epidemic of mycoplasma pneumonia, the number of registered outpatient clinics and emergency departments in pediatrics hangs 300 to 400 every day, which has far exceeded the usual number of outpatient clinics. Medical staff are often busy until three or four in the afternoon to have lunch, or take turns to eat. At present, the children with respiratory diseases in outpatient clinics are mainly influenza, among which B-stream accounts for a large proportion, which seems to be few people. In fact, the number of outpatient visits exceeds 200 every day, including about 30-40 plus signs. During the interview, two children’s families found Li Lixiang one after another.
When the child is sick, the whole family is anxious, and it is inevitable that parents will leave things behind when they take their children to see a doctor. At the nurse station, there is a thick stack of medical insurance cards. The Beijing News reporter counted 50 cards, including two medical insurance cards lost that day. Li Li said that these are all medical insurance cards that have not been recovered since September last year, and many of them were left by parents on the registered payment machine. While talking, a parent found the nurse station to look for the lost medical insurance card.
The proportion of B-stream increased, and the proportion of myositis in children increased.
The China Influenza Surveillance Weekly released by China National Influenza Center on January 4th, 2023 (December 25th, 2023-December 31st, 2023) shows that the positive rate of influenza virus detection in southern provinces increased this week, while that in northern provinces decreased. Subtype A(H3N2) is the main strain, and the proportion of strain B(Victoria) continues to increase. 110 outbreaks of influenza-like cases were reported nationwide. Recently, the proportion of B-stream has been on the rise, rising for 9 consecutive weeks in the north, from 4.2% in the 44th week to 47.3% in the 52nd week. South China rose for six consecutive weeks, from 11.6% in the 47th week to 26.4% in the 52nd week. The proportion of B-stream in China has increased for six consecutive weeks.
This point was also confirmed by the Beijing News reporter from Peking University People’s Hospital as the national influenza surveillance sentinel. Recently, among the influenza patients admitted to the hospital, B-stream has increased significantly, accounting for about 2/3, and the proportion of myositis in children with B-stream has increased.
Myositis is one of the common symptoms after being infected with hepatitis B virus. Many patients infected with hepatitis B complain of leg pain, and myositis is the chief culprit.
"Myositis is a virus infection that causes muscle cells to be destroyed, mainly manifested as muscle soreness. Blood tests will find that creatine kinase is relatively high. Both A stream and B stream will have symptoms of muscle soreness, but B stream is more prone to acute myositis. " Ding Mingming, an attending physician in pediatrics at Peking University People’s Hospital, said that the muscle soreness caused by myositis is more prominent in the lower limbs, because the leg muscles are the largest muscle group in the human body, and the muscle soreness caused by the destruction of muscle cells caused by virus infection will be more intense.
For adults, Wang Yue, an attending physician in the fever clinic of the Infectious Diseases Department of Peking University People’s Hospital, said that in influenza surveillance, two weeks ago, it was suddenly found that influenza A and influenza B began to cross, and the positive rate of influenza A gradually decreased and the positive rate of influenza B increased. At present, the proportion of influenza B in adult patients has reached about 2/3. However, compared with children, the incidence of myositis in adults has not changed significantly. "From the influenza monitoring in our department, influenza A is often the main epidemic strain in the peak period of autumn and winter, and the epidemic of influenza B will be mixed at the end of the influenza season. However, every 4-5 years, B-stream will become the main epidemic strain of the year, which may be caused by the long-term non-epidemic of B-stream and the lack of immunity to B-stream virus. " Wang Yue, attending physician of fever clinic of infectious diseases department of Peking University People’s Hospital, said.
The same is true of the infectious disease clinic in Beijing Hospital of Integrated Traditional Chinese and Western Medicine. According to Da Huijuan, deputy chief physician of the Department of Respiratory and Gastroenterology, Beijing Hospital of Integrated Traditional Chinese and Western Medicine, since mid-December, the number of outpatients with respiratory infections in the hospital has decreased compared with the previous two months, and the proportion of A stream has gradually decreased, while the proportion of B stream has increased. "This wave of B-stream didn’t grow as fast as before when A-stream was high. Most of the patients were young children, teenagers and middle-aged, but not many elderly people saw a doctor, which may be related to the annual vaccination of the elderly over 60 years old."
For the treatment of influenza, Wang Yue and Ding Mingming both said that the efficacy of the antiviral drugs oseltamivir and mabaloxavir is very clear. As far as treatment is concerned, it is of little significance to distinguish between influenza A and influenza B, because the treatment principles are basically the same. Typing influenza viruses is mainly to monitor epidemic trends.
Elderly people with basic diseases should be vaccinated against influenza in particular.
During the school flu vaccination period in 2023, some parents reported that only 8 of the 36 students in the class were willing to be vaccinated, and the parents of 5 of them were doctors.
In this regard, Ding Mingming said that the current national influenza vaccination rate is basically maintained in single digits. "Many people are concerned about adverse reactions after vaccination, but in fact this probability is very low, and the common adverse reactions are also lighter than the symptoms of influenza infection." It takes 2-4 weeks for the flu vaccine to take effect. It is recommended to vaccinate in September or October before the arrival of the flu season. If you missed the vaccination before, it will still be effective now, because the flu vaccine can last for about one year. If you vaccinate now, it may still be effective in the next flu season. "Ding Mingming said.
Why is the public’s enthusiasm for influenza vaccination low? According to Wang Yue’s analysis, the effect of influenza antiviral drugs is too good, and it takes effect quickly after taking medicine. In addition, compared with vaccination, it may be more convenient to buy medicine, which leads many people to be unwilling to get vaccinated.
In adult influenza prevention, Wang Yue especially recommends that the elderly with basic diseases should be vaccinated as soon as possible, especially those over 65 years old with basic diseases, which may cause more serious consequences. "We are afraid that the flu will cause severe pneumonia in the elderly, and we are afraid that there will be fluctuations in basic diseases after being infected with the flu, which will aggravate basic diseases, such as diabetes and chronic obstructive pulmonary disease, which will be life-threatening." Wang Yue said that among the elderly influenza patients admitted by the department, there were patients whose basic diseases fluctuated severely due to influenza. One of the elderly people’s asthma is well controlled on weekdays, and he can no longer take medicine. However, because his family was infected with the flu and he was not vaccinated against the flu, he was infected, which triggered an acute attack of asthma and led to respiratory failure.
Wang Yue pointed out that the World Health Organization has guidance documents on influenza vaccine, which will predict the strains that may be prevalent in the new influenza season in advance, and provide basis for influenza vaccine manufacturers. However, the predicted strain may deviate from the actual epidemic strain, which may lead to the vaccine miss target. Judging from the monitoring of influenza epidemic season this year, the vaccine strain and epidemic strain are relatively close, and the vaccination effect should be good. However, influenza vaccination does not mean that you will not get the flu 100%, because the vaccination effect depends on the immune status of people. Some people may establish a relatively good immune barrier after vaccination, which will have a better effect on resisting influenza virus, which has nothing to do with age and weight. "The flu vaccine has a stable effect and its safety has been verified for a long time. It is recommended to vaccinate before the flu season, not only for yourself, but also for people around you, especially high-risk groups, such as children, the elderly and pregnant women." Wang Yue stressed.
Beijing News reporter Wang Kara Liu Xu Image source Photo by Zhong Yanyu, Peking University People’s Hospital
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