[Friendship Science] Respiratory pathogens are getting together, what should I do？

In dry and cold climate, the defense function of human respiratory tract is easy to decrease, so every winter is the season of high incidence of respiratory tract infections. This year’s situation is a bit special. Although the common respiratory pathogens are popular in previous years, they can’t hold back and launch an offensive, making many children and even adults recruited.

Judging from the current situation, mycoplasma pneumoniae, influenza virus, respiratory syncytial virus and adenovirus are the main causes of respiratory infection in children this year. In view of these pathogens, we asked Fu Peipei, the pediatric attending physician of Beijing Friendship Hospital, to sort out their respective infection characteristics, clinical manifestations, treatment methods and preventive suggestions, hoping to help everyone spend the epidemic peak of respiratory infection more effectively and smoothly.

Mycoplasma pneumoniae

Mycoplasma pneumoniae is a pathogen between bacteria and viruses, and children are generally susceptible. Pneumonia caused by this pathogen is common in preschool and school-age children.

In Beijing, the previous epidemic season of mycoplasma pneumoniae was winter, and most of them were mild. Compared with previous years, the epidemic time of Mycoplasma pneumoniae was earlier this year, and it spread widely, and the cases of severe pneumonia and refractory pneumonia increased significantly. However, from the overall situation of children infected with mycoplasma pneumoniae, upper respiratory tract infection is still the majority.

symptom

After being infected with mycoplasma pneumoniae, the main symptom is fever or cough. Children with mild illness may have mild fever or cough, and some of them will get better on their own. When pneumonia develops, children often show moderate or high fever, severe cough, and even spasmodic cough like pertussis and prolonged cough. More serious severe mycoplasma pneumonia usually occurs in the course of about 1 week, and children may have shortness of breath or dyspnea.

suggestion

Persistent high fever > 3 days or fever > 7 days, or dyspnea, chest pain, poor spirit, headache, convulsions, frequent vomiting, etc., it is recommended to seek medical advice in time.

treat

For mycoplasma pneumoniae infection, the first choice drugs are still macrolides, including azithromycin, erythromycin and clarithromycin. For drug-resistant mycoplasma infection, children over 8 years old can choose tetracycline drugs, such as doxycycline and minocycline.

Children with mild pneumonia need not be hospitalized, but can be observed and treated at home; Children with severe pneumonia are advised to be hospitalized in time. Parents should not give their children antibiotics by themselves, but must choose a treatment plan suitable for their children’s condition under the guidance of a doctor.

prevent

It should be noted that Mycoplasma pneumoniae is mainly transmitted through respiratory droplets, and the incubation period is 1-3 weeks. At present, there is no vaccine to prevent Mycoplasma pneumoniae. Developing good hygiene habits, such as wearing masks and washing hands frequently, is the main means to avoid infection.

Influenza virus

Influenza, referred to as influenza for short, is an acute respiratory infectious disease caused by influenza virus. Influenza A and B are seasonal epidemic every year, and generally all parts of China have entered the influenza epidemic season since October.

According to the data released by the Beijing Municipal Center for Disease Control and Prevention, the number of influenza cases in Beijing has increased rapidly recently, and it is prevalent with many other pathogens. For influenza virus, people are generally susceptible, and children under 5 years old and elderly people over 65 years old are prone to serious complications, so they are also called high-risk groups of influenza.

symptom

After being infected with influenza virus, fever, headache, myalgia and general malaise are the main manifestations, and the body temperature can be as high as 39℃-40℃. Some children have cough, but it is not severe, and it can also be accompanied by nasal congestion, runny nose and conjunctival congestion. Children infected with B-stream may have digestive tract symptoms such as vomiting, abdominal pain and diarrhea. When the newborn is infected with influenza, it can be manifested as drowsiness, refusal to milk, apnea and so on.

Some mild children can get better on their own, and their fever gradually decreases after 3-4 days of onset, and their systemic symptoms get better, but it may take a long time for cough and physical recovery. Severe children may have serious complications such as pneumonia, myositis, acute necrotizing encephalopathy and septic shock.

suggestion

For children with persistent high fever for more than 3 days, or with symptoms such as dyspnea, poor spirit, chest pain and frequent vomiting, it is recommended to seek medical advice in time.

treat

The main treatment of influenza is antiviral therapy, and three drugs are often used in clinic: 1. Neuraminidase inhibitors, such as oseltamivir, zanamivir, palamivir, etc., can prevent the virus from being released from host cells and have the effect of resisting influenza A and B; 2. Balofloxacin can inhibit the initiation of mRNA synthesis and prevent virus proliferation. It is effective for both influenza A and influenza B, and is suitable for children aged ≥5 years and weighing ≥20kg. 3. Adamantane drugs, which act on M2 protein of influenza A virus, can prevent the virus from replicating efficiently, but have no effect on influenza B virus. However, the strains of influenza A virus spread since 2009 are generally resistant to adamantane drugs and are not recommended.

prevent

The incubation period of influenza virus is 1-7 days, usually 2-4 days. Vaccination against influenza is the most effective means to prevent influenza, which can reduce the incidence of influenza and the risk of serious complications. High-risk groups with a history of contact with influenza virus can take drugs within 48 hours, such as taking oseltamivir or zanamivir (the dose is the same as the therapeutic dose, once a day for 7 days).

Respiratory syncytial virus

Respiratory syncytial virus (RSV) is the most important virus pathogen causing acute lower respiratory tract infection in children under 5 years old worldwide. In addition, it is also an important pathogen of acute lower respiratory tract infection in the elderly and immunocompromised people. Respiratory syncytial virus can also cause upper respiratory tract infections such as rhinitis and colds in older children and adults.

symptom

The clinical manifestations of children infected with respiratory syncytial virus vary greatly. Children’s early respiratory syncytial virus infection is mostly confined to the upper respiratory tract, showing symptoms such as fever, stuffy nose, runny nose and cough. It can also develop into pneumonia, which is common in infants and children under 2 years old. It is characterized by cough, excessive phlegm, wheezing, dyspnea and feeding difficulties.

suggestion

Infants and young children are infected with respiratory syncytial virus, so it is suggested to check the etiology in time, and pay attention to the breathing situation of children. If they have difficulty breathing, wheezing and poor mental health, they should seek medical advice in time.

treat

At present, there is no specific drug for respiratory syncytial virus infection, and people with normal immune function are generally self-limited after infection, and do not need special treatment, which will rarely cause serious complications. The main treatment principle is symptomatic support treatment to relieve the symptoms of cough, wheezing and dyspnea in children. For children with lower respiratory tract infection, interferon antiviral therapy can be tried.

prevent

The incubation period of respiratory syncytial virus is 2-8 days, usually 4-6 days. At present, there is no respiratory syncytial virus vaccine for children. Palizumab is a specific antibody against respiratory syncytial virus, which can be used to prevent infection in high-risk groups, but it has not been introduced into domestic clinical application. Therefore, developing good hygiene habits is still the main means to avoid infection at present.

adenovirus

Adenovirus is a common virus of respiratory tract infection in children, and it is also one of the more serious types of community-acquired pneumonia in children. Acute infectious diseases caused by adenovirus easily invade respiratory tract and digestive tract mucosa, conjunctiva, urinary tract and lymph nodes, mainly manifested as acute upper respiratory tract infection, followed by eye and gastrointestinal tract infection. People are generally susceptible, especially children, and infants are prone to adenovirus pneumonia, with serious illness and high mortality.

symptom

Children infected with adenovirus often show high fever, and most of them have high fever above 39℃ at the beginning of the disease, which may be accompanied by cough and wheezing (wheezing is usually seen in infants aged 6 months to 2 years). Mild children’s body temperature can return to normal in about 7-11 days, and other symptoms will disappear; Severe children with high fever can last for 2-4 weeks, and dyspnea usually begins 3-5 days after illness, accompanied by symptoms of systemic poisoning, listlessness or irritability, irritability and even convulsions. Some children have diarrhea, vomiting, and even severe abdominal distension. A few children have conjunctival congestion and tonsil secretion.

suggestion

For children with adenovirus infection, besides observing their body temperature changes, they also need to observe their breathing conditions. If they have difficulty breathing, wheezing, poor spirits and frequent vomiting, they should seek medical advice in time.

treat

Similar to the situation of respiratory syncytial virus, there is no specific drug for adenovirus infection, and people with normal immune function are self-limited after being infected with adenovirus and do not need special treatment. In most cases, the treatment principle of adenovirus is symptomatic supportive treatment, mainly to relieve children’s discomfort such as high fever and cough. Children with serious complications need to be hospitalized in time.

prevent

The incubation period of adenovirus is generally 2-21 days, with an average of 3-8 days. Similarly, there is no vaccine to prevent adenovirus infection. The main preventive measure to avoid infection is still to develop good hygiene habits.

Physician’s explanation

Can I take medicine by myself after seeing the test results of mycoplasma?

At present, there are many methods to detect mycoplasma pneumoniae infection in clinic, but sometimes the test results are false positive or false negative. Why?

1. Detection of Mycoplasma pneumoniae nucleic acid

The specimen of this detection method is throat swab or nose swab, which can be used for RNA or DNA detection. RNA can be degraded with the death of Mycoplasma pneumoniae, so it can be used as an index to evaluate the infection, prognosis and drug efficacy of Mycoplasma pneumoniae. After the death of Mycoplasma pneumoniae, DNA can still exist in some patients for 7 weeks to 7 months, and it is not easy to degrade, so the DNA test results can not be used to evaluate the acute infection and treatment effect of Mycoplasma pneumoniae.

2. Detection of Mycoplasma pneumoniae antibody
The specimen of this detection method is blood, and some hospitals can collect fingertip peripheral blood. IgM antibody is the most common detection method. Because this antibody generally starts to rise within 1 week of the initial infection, reaches the peak in 2-3 weeks, drops in 3-4 weeks, and drops to the lowest in 2-3 months, therefore, the positive antibody does not mean that the child currently has acute infection with Mycoplasma pneumoniae.

In addition, some hospitals can detect PA (total antibody) in venous blood, and the serum antibody titer of children with mycoplasma pneumoniae is ≥1∶160 as the diagnostic standard of recent or acute infection of mycoplasma pneumoniae, but the positive detection rate is also limited due to the time window limitation of antibody appearance.

To sum up, various detection methods have their advantages and disadvantages. Among them, the RNA detection with high accuracy is limited by the sampling method and the cooperation degree of children, and false negative can also occur; Although IgM antibody detection is convenient, its accuracy is not good. Therefore, parents should not judge by themselves when they see the relevant test results. They need to consult a doctor and listen to professional treatment advice.