Symptoms of Mycoplasma pneumoniae infection

Pneumonia caused by Mycoplasma pneumoniae is already a very common pneumonia phenomenon. Pneumonia has a great impact on our lives. If you suffer from pneumonia, you will have symptoms of coughing. Generally, the onset of such pneumonia is very slow, and you will also have symptoms of fever and obvious changes in the lungs. It is also a threat to the patient's life and health. Everyone must be clear about the symptoms of Mycoplasma pneumoniae infection.

1 Causes

The pathogen is Mycoplasma pneumoniae, a microorganism between bacteria and viruses, without a cell wall structure, facultative anaerobic, and the smallest microorganism that can live independently. It is mainly transmitted through the respiratory tract. Healthy people are infected by inhaling oral and nasal secretions emitted when patients cough or sneeze. Pathogens usually exist between the ciliated epithelium of the respiratory tract and do not invade the lung parenchyma. They adsorb to the surface of the host respiratory epithelial cells through the neuraminic acid receptor sites on the cell membrane, inhibit ciliary activity and destroy epithelial cells.

2 Clinical manifestations

The onset is slow, with an incubation period of about 2 to 3 weeks. At the beginning of the disease, patients experience general discomfort, fatigue, and headache. Fever develops 2 to 3 days later, with the temperature often reaching around 39°C and lasting for 1 to 3 weeks, and may be accompanied by sore throat and muscle aches.

Cough is the most prominent symptom of this disease, which usually begins 2 to 3 days after the onset of the disease. It is a dry cough at first, and then turns into a stubborn and severe cough, often with thick sputum occasionally stained with blood. In a few cases, it may be similar to whooping cough. It can last for 1 to 4 weeks. Pulmonary signs are often subtle or even absent. A few people can hear dry and wet music. However, many of the masses disappeared, so the physical signs were inconsistent with the clinical manifestations such as severe cough and fever, which is one of the characteristics of this disease. Infants and young children have an acute onset, a long course, and more severe conditions, with symptoms such as dyspnea, wheezing, and more prominent wheezing, and more lung rales than older children. Some children may suffer from hemolytic anemia, meningitis, myocarditis, groin, Green-Barry syndrome and other extrapulmonary manifestations.

3. Inspection

The diagnosis is based on a combination of clinical symptoms, X-ray findings, and serological test results. Although the isolation of Mycoplasma pneumoniae by culture is of decisive significance for diagnosis, its detection rate is low, the technical conditions required are high, and the time required is long. Serological tests have certain reference value, especially for those with a 4-fold increase in serum antibodies. This disease should be differentiated from viral pneumonia, Legionella pneumonia, etc. The normal number of peripheral blood eosinophils can be distinguished from eosinophilic pulmonary infiltration.

1. Chest X-ray

The lung texture increases, and the lung parenchyma appears spotted, patchy or uniformly blurred.

2. Etiological examination

Sputum, nose, and throat swabs were cultured for Mycoplasma pneumoniae.

3. Serological examination

Serum pathogen antibody titer >1:32, streptococcal MG agglutination test, titer ≥1:40 is positive, and two consecutive increases of 4 times or more have diagnostic value.

The total number of peripheral blood leukocytes is normal or slightly increased, mainly neutrophils. Two weeks after onset, about two-thirds of patients have a positive cold agglutination test, with a titer greater than 1:32, which is of diagnostic value, especially when the titer gradually increases. About half of the patients had a positive agglutination test for Streptococcus MG. Further confirmation of the diagnosis depends on the determination of mycoplasma IgM antibodies in the serum (enzyme-linked immunosorbent assay is the most sensitive, immunofluorescence assay is highly specific, and indirect hemagglutination assay is more practical). Antigen detection can be performed using the PCR method, but the reagent kit needs to be improved to increase sensitivity and specificity.

Pneumonia caused by Mycoplasma pneumoniae is very common in autumn, and its disease progression is very slow, which has a great impact on the patient's health. In daily life, there will be symptoms of constant coughing, which makes patients feel very painful. Everyone should know the symptoms of Mycoplasma pneumoniae infection. If such symptoms occur, they should be checked and treated in time.