Experts from the Department of Respiratory and Critical Care Medicine at Beijing Hospital explain to you what you need to know about Mycoplasma pneumonia

The first-line treatment for mycoplasma pneumonia is macrolide antibiotics, including azithromycin, erythromycin, clarithromycin, etc. The more familiar penicillin and cephalosporin antibiotics are ineffective in treating mycoplasma pneumonia.

Recently, mycoplasma pneumonia has received widespread attention. Although both are accompanied by cough and fever, the symptom cycle of mycoplasma pneumonia is longer than that of colds, and it has shown a certain regional outbreak trend since the beginning of autumn this year. According to the epidemic pattern of mycoplasma, this year is a "big year" for mycoplasma infection.

How to scientifically understand and effectively prevent Mycoplasma pneumonia? Can I take medicine on my own to treat Mycoplasma pneumonia? What should I pay attention to? Under what circumstances should I seek medical attention immediately? In response to these issues of general concern to society, "Outlook Weekly" recently interviewed Ju Yang, deputy chief physician of the Department of Respiratory and Critical Care Medicine and director of the Department of Infectious Diseases at Beijing Hospital.

Accurate identification

"Oriental Outlook Weekly": What are the pathogenesis, high-risk populations and main symptoms of Mycoplasma pneumonia?

Ju Yang: The full name of mycoplasma pneumonia is "Mycoplasma pneumonia", which refers to lung inflammation caused by Mycoplasma pneumonia infection, which can affect the bronchi, bronchioles, alveoli and lung interstitium. The pathogenesis has not yet been fully elucidated, and it is currently believed that there are two main mechanisms: direct damage by mycoplasma and abnormal host immune response. The first is that mycoplasma invades the respiratory tract, attaches to the cell surface using adhesion organelles, and causes direct damage to the respiratory epithelium through mechanisms such as the release of oxygen free radicals; the second is that the host's abnormal immune response to mycoplasma infection can cause immune damage to the lungs and extrapulmonary tissues through multiple pathways such as autoimmune reactions, allergic reactions, and immune complex formation.

In recent years, there have been more reports of mycoplasma pneumonia in children under 5 years old. In fact, people of all ages are generally susceptible to mycoplasma pneumonia, and children are the most susceptible group. For some elderly patients with underlying diseases, such as diabetes and hypertension, they may develop severe pneumonia after being infected with mycoplasma or chlamydia.

Mycoplasma pneumonia usually has a slow onset, and clinical symptoms vary in severity. Generally, clinical symptoms are mild, but there have been reports of individual severe cases and even death. The most typical symptoms of mycoplasma pneumonia are fever and cough. In the early stage, it is a paroxysmal, irritating dry cough. As the disease progresses, cough and sputum will appear. Some patients with severe symptoms will experience wheezing, dyspnea, cyanosis, etc., and may also have extrapulmonary symptoms such as skin and mucous membranes, blood system, nervous system, cardiovascular system, and digestive system. You should be highly vigilant about changes in symptoms and seek medical attention as soon as possible.

Oriental Outlook: In clinical diagnosis, how to distinguish common pneumonia, influenza and mycoplasma pneumonia? How to distinguish between novel coronavirus infection and mycoplasma infection?

Juyang: Identification is mainly based on etiological examination. In the early stage of common pneumonia, especially within 3 days, the total white blood cell count, neutrophil percentage, C-reactive protein, procalcitonin and other indicators increase. The treatment plan for common pneumonia is mainly based on antibacterial drugs.

Influenza is common during the influenza season. Most cases have a history of contact with influenza or suspected influenza patients. The onset is fever and upper respiratory tract infection symptoms. When influenza virus pneumonia occurs, there will be worsening cough, dyspnea and lung signs. The imaging is sometimes similar to mycoplasma pneumonia. The diagnosis can be confirmed by positive influenza A or B virus antigen or nucleic acid in respiratory specimens. The main drugs for the treatment of influenza include oseltamivir, mabaloxavir, etc.

Mycoplasma pneumonia is caused by infection with Mycoplasma pneumoniae, which is a lower respiratory tract infection and is somewhat contagious. Typical symptoms of mycoplasma pneumonia include: fatigue and myalgia, which usually resolve on their own after 2-3 days; fever, which is generally moderate and can last for 2-3 weeks. Children and the weak may have high fever; cough, which is mostly persistent and severe dry cough, as well as headache, sore throat and other symptoms. Some patients may have nasopharyngeal and ear pain, shortness of breath, dyspnea, and even cervical lymphadenopathy, hemolytic anemia, myocarditis, meningitis, etc. Mycoplasma pneumonia is mostly self-limiting. Even if the patient does not take treatment measures, timely replenishment of water and electrolytes can also heal on their own, but it is recommended that those with more obvious or severe symptoms should be treated as soon as possible. The main drugs include azithromycin, levofloxacin, etc.

COVID-19 infection is caused by infection with COVID-19. Most people have a history of contact with COVID-19 or suspected COVID-19 patients and are also contagious. COVID-19 infection and Mycoplasma pneumoniae infection can be differentiated through nucleic acid testing of respiratory specimens.

Take medicine according to doctor's instructions

"Oriental Outlook Weekly": What is the treatment plan for Mycoplasma pneumonia?

Ju Yang: The first-line treatment for mycoplasma pneumonia is macrolide antibiotics, including azithromycin, erythromycin, clarithromycin, etc. The more familiar penicillin and cephalosporin antibiotics are ineffective in treating mycoplasma pneumonia.

The general treatment and symptomatic treatment of Mycoplasma pneumonia are similar to those of other respiratory infections. For example, patients with severe cough should be given appropriate cough suppressants; expectorants include oral and nebulized drugs, and can also be assisted by physical therapies such as mechanical expectoration and percussion expectoration; patients with high fever can be given antipyretic drugs; adequate rest and energy intake should be ensured to ensure water and electrolyte balance.

Oriental Outlook: When symptoms occur, some parents will use medication on their own based on experience. What should they pay attention to? What are the potential risks? What symptoms indicate that they need to see a doctor immediately?

Ju Yang: Parents must use medication under the guidance of professional doctors and do not use antibiotics on their children. If you suspect your child has mycoplasma pneumonia, it is recommended to take your child to the hospital for a clear diagnosis, assess the severity of the disease, and develop a treatment plan.

If you take medication on your own, you must pay attention to the therapeutic effects and adverse reactions of the drugs. Macrolide antibiotics are the first choice for the treatment of mycoplasma pneumonia in children, including azithromycin, clarithromycin, erythromycin, roxithromycin, etc. Although azithromycin is the first choice for the treatment of Mycoplasma pneumonia infection, it should not be used casually, and irregular mixing of drugs may cause serious consequences. Self-medication is risky, because non-medical professionals may lack relevant knowledge about the efficacy and adverse reactions of drugs, which may cause the patient's condition to worsen and delay treatment.

Therefore, if the patient's condition worsens after self-medication, they should seek medical attention in time. These symptoms include but are not limited to: persistent high fever 72 hours after treatment; symptoms of infection and poisoning, such as low blood pressure, cold limbs, and decreased consciousness; wheezing, shortness of breath, dyspnea, chest pain, hemoptysis, etc.; hypoxemia and dyspnea that are difficult to relieve or progress after treatment; and pulse oxygen saturation of ≤93% when breathing air at rest. In addition, patients with underlying diseases, including asthma and primary immunodeficiency disease, should also seek medical attention in time if they are infected with mycoplasma.

Oriental Outlook: What causes mycoplasma pneumonia patients to become resistant to conventional treatment drugs? How should we deal with it?

Ju Yang: The resistance of Mycoplasma pneumoniae to macrolide antibiotics is mainly due to the occurrence of resistance-related gene mutations in its genome. Mycoplasmas carrying resistance genes have reduced binding ability with macrolide drugs, leading to treatment failure.

In response to the high rate of macrolide resistance, relevant medical associations in my country have successively formulated expert consensus and guidelines for the diagnosis and treatment of Mycoplasma pneumoniae infection in adults and children, and formulated detailed treatment plans for people of different ages and with different clinical characteristics.

In routine clinical diagnosis and treatment, only macrolide drugs are available for children under 8 years old. Children aged 8-18 years old and adolescent patients can achieve satisfactory results with tetracycline drugs (including doxycycline and minocycline). For people over 18 years old, fluoroquinolones (representative drugs levofloxacin, moxifloxacin, etc.) can also be considered. It should be noted that the guidelines clearly state that the use of tetracycline drugs by patients under 8 years old and the use of fluoroquinolones by children under 18 years old are off-label uses, and the pros and cons need to be carefully considered, and the potential adverse reactions should be explained in detail to parents, and informed consent should be obtained before the use of the drugs.

Scientific prevention

"Outlook Weekly": Mycoplasma pneumonia will experience cyclical epidemics, and this year happens to be in the epidemic period. Will the understanding of this cyclical law help us scientifically prevent mycoplasma infection?

Ju Yang: Mycoplasma pneumonia occurs periodically in a region every 3-7 years, and the epidemic period can last up to 1 year. The incidence rate in epidemic years can be several times that of non-epidemic years. Mycoplasma pneumonia has been on the rise recently, and it is crucial to do a good job of prevention and standardized treatment after the onset of the disease. The understanding of this cyclical law can remind us to strengthen the protection against mycoplasma infection, improve the identification and detection of mycoplasma infection, and make timely diagnosis and treatment.

"Outlook Weekly": How to effectively prevent Mycoplasma pneumonia in daily life?

Juyang: There is currently no vaccine to prevent Mycoplasma pneumoniae infection, so prevention is crucial. The following measures can help prevent Mycoplasma infection: Mycoplasma pneumonia patients are still contagious during the incubation period until the symptoms ease for several weeks, so they should avoid contact with people with low immunity and infants, and disinfect the items used by patients; avoid staying in densely populated areas during the high-incidence season for prevention, and wear protective masks in densely populated areas; develop good hygiene habits: pay attention to hand hygiene, wash hands frequently, and ventilate frequently; avoid going to crowded and poorly ventilated public places, and wear masks when necessary; cover your mouth and nose with a tissue when coughing or sneezing, and throw the used tissue into the trash can; keep your hands clean, wash your hands frequently with soap and hand sanitizer under running water; pay attention to indoor ventilation, and ventilate for no less than 30 minutes each time; eat a balanced diet, get enough sleep, strengthen physical exercise, strengthen your physical fitness, and improve your resistance.

Oriental Outlook: For children who have been infected with mycoplasma pneumonia, will they be infected again after recovery? What are the special rehabilitation measures? What precautions should patients of different degrees take after recovery?

Juyang: Although IgG antibodies can be present for a long time after infection, immunity will not last long. Immunity needs to be improved: proper exercise, balanced nutrition, and avoid staying up late. Developing good hygiene habits is important to avoid infection.

Generally speaking, if it is a mild case, it will recover in 7-10 days, and the prognosis is usually good without sequelae. If it is a severe case, it may be accompanied by pleural effusion and atelectasis, and mediastinal gas, necrotizing pneumonia, etc. may also occur. A small number of critical cases develop rapidly, and respiratory distress may occur, and even respiratory support may be required. For severe and a small number of critically ill patients, regular reexaminations are required according to the doctor's advice after recovery.

Source: WeChat official account of Oriental Outlook Weekly, WeChat official account of Beijing Hospital