What Causes Walking Pneumonia in Adults?

Chlamydia pneumoniae infection is an infectious disease caused by Chlamydia pneumoniae, which mainly causes atypical pneumonia in adults and adolescents, and can also cause acute respiratory infections such as bronchitis, pharyngitis and tonsillitis. According to statistics, the cause of pneumonia is the third major pathogen that causes community-acquired pneumonia after pneumococcus and Haemophilus influenzae. The positive rate of serum Chlamydia pneumoniae antibodies in patients with respiratory infections was 54.8%, and those with severe infections were 24.8%.

Basic Information

Visiting department: Respiratory
Multiple groups: Adults and teenagers

Common causes: Infections caused by Chlamydia pneumoniae
Common symptoms: Fever, general malaise, sore throat, hoarseness, cough, headache, etc.

Causes of Chlamydia pneumoniae infection

The pathogen of this disease is Chlamydia pneumoniae. In 1965, Grayston first isolated a Chlamydia different from other Chlamydia in the conjunctival secretions of children in Taiwan, China. At that time, it was named TW (Taiwan) -183. In 1983, a college student with acute respiratory infection in Seattle In the secretions of the body, another strain of Chlamydia was isolated and named AR-39 (acuterespiratory-39). After research and identification, the two strains were found to be the same type of Chlamydia. In 1989, it was officially named TWAR, also called Chlamydia pneumoniae.

Clinical manifestations of Chlamydia pneumoniae infection

Acute respiratory infection

It is its main manifestations, such as pharyngitis, laryngitis, otitis media with sinusitis, bronchitis, and pneumonia. Pneumonia is the most common, followed by bronchitis. Pneumonia is more common in the elderly, and bronchitis and upper respiratory tract infections are more common in adolescents under the age of 20. Fever, general discomfort, sore throat, and hoarseness onset, coughing a few days later, at this time the temperature is mostly normal. It can also cause bronchitis and bronchial asthma. Patients with original bronchial asthma can get worse after being infected with Chlamydia pneumoniae. In severe cases, people can die from aggravation of the underlying disease or from complications such as bacterial infection.

2. Typhoid

Few patients show high fever, headache, relatively slow pulse, and hepatosplenomegaly, and are prone to myocarditis, endocarditis, and meningitis. Severe patients have coma and acute renal failure, and their performance is similar to severe typhoid fever.

3. Other

Can cause iritis, hepatitis, endocarditis, meningitis, and nodular erythema. Is an important cause of secondary infections such as AIDS, malignant tumors or leukemia. In recent years, it has been found that Chlamydia pneumoniae infection is common in COPD. And found that the positive rate of Chlamydia pneumoniae-specific antibodies was significantly higher in COPD patients than in healthy people. In particular, more than 4% of acute episodes of COPD patients> 50 years of age are associated with Chlamydia pneumoniae infection.

Chlamydia pneumoniae examination

Laboratory inspection

(1) Blood counts and white blood cell counts are usually normal, which can be increased in severe patients. ESR

(2) Etiological examination is a reliable method to confirm the diagnosis.

(3) The micro-immunofluorescence test (MIF) is currently the international standard and the most commonly used serological diagnostic method for Chlamydia pneumoniae. Except for STD outpatients and prostitutes, the MIF serological diagnosis of Chlamydia pneumonia can use Chlamydia pneumoniae. A single antigen, ie, it is not necessary to detect both Chlamydia trachomatis and Chlamydia psittaci antibodies at the same time. Serological diagnostic criteria are: MIF test IgG 1: 512 and / or IgM 1: 32. After excluding false positives caused by rheumatoid factor (RF), a recent infection can be diagnosed. Double serum antibody titers 4 A fold or more increase was also diagnosed as a recent infection. 1: 16IgG <1: 512 is a previous infection.

(4) PCR method for detection of Chlamydia pneumoniae DNA, the sensitivity is higher, and it can be distinguished from other species of Chlamydia.

2. Other auxiliary inspections

X-ray examination of the lungs: atypical pneumonia, usually unilateral stage pneumonia, severe lesions may even spread to both lungs, and may be accompanied by pleurisy or pleural effusion.

Diagnosis of Chlamydia pneumoniae infection

Due to the lack of specific clinical manifestations of this disease, patients with pneumonia or the above clinical manifestations may be diagnosed with an etiology or immunological test if they are suspected of having this disease.

Differential diagnosis of Chlamydia pneumoniae infection

The disease must be distinguished from pneumonia caused by other pathogens, such as mycoplasma pneumonia, viral pneumonia, severe acute respiratory syndrome (SARS), legionnaires disease, and other bacterial pneumonia. Among them, SARS is characterized by:

1. Epidemiological characteristics

It is one who has close contact history with the affected person, or is one of the infected group, or has evidence of clear infection. Or have visited or lived in an area where a report of patients with the disease and secondary infection occurred within 2 weeks before the onset of illness.

2. Clinical manifestations

It is acute, with fever as the first symptom, and the body temperature is> 38 ° C. It may be accompanied by headache, joints, muscle aches, cough, less phlegm, and chest tightness. In severe cases, breathing difficulties or respiratory distress occur, and the lung signs are not obvious, but there may be a little Wet rales or consolidation of the lungs.

3. Peripheral blood leukocytes and lymphocytes can be reduced.

4. Flake, patchy or reticular changes in the lungs

Others are mainly determined by their respective etiology and / or serum immunological examination.

Complications of Chlamydia pneumoniae infection

May be complicated by endocarditis, myocarditis, and meningitis.

Chlamydia pneumoniae treatment

Chlamydia pneumoniae is extremely sensitive to tetracycline, erythromycin, and fluoroquinolone drugs, and resistant to sulfa. Therefore, tetracycline or erythromycin is commonly used orally. Doxycycline can also be used. Tetracycline and quinolone drugs are contraindicated in pregnant women and lactating women and children. Clarithromycin (clarithromycin) can be used in children for better results. Some patients can relapse after discontinuation, especially those treated with erythromycin, and then treated with doxycycline is still effective. In recent years, azithromycin, a new macrolide antibiotic, has been found to have a high sensitivity to Chlamydia pneumoniae in vitro and to enter cells with high sensitivity and low gastrointestinal response.

Prognosis of Chlamydia pneumoniae infection

Chlamydia pneumoniae infections are mostly asymptomatic or mild, with occult infections as high as 90%. In general, fragile and ill patients occasionally die.