Chlamydophila pneumoniae pneumonia

　　1. Etiology of the disease

　　The pathogen is Chlamydia trachomatis, which was first isolated and cultured successfully by Chinese scholars in 1995.

　　2, Pathogenesis

　　Chlamydia trachomatis includes 15 serotypes. It causes trachoma (A, B, Ba, and C), lymphogranuloma venereum (11, 12, and 13), inclusion conjunctivitis, genitourinary tract infections (this is considered the most common sexually transmitted disease in developed countries), and neonatal pneumonia (serotypes D-K). Chlamydia trachomatis male genitourinary tract infection is mainly manifested as non-gonococcal urethritis, epididymitis, and Reiter's syndrome; in women, it is manifested as cervicitis, endometritis, and pelvic inflammatory disease. During delivery, the fetus can be infected with neonatal pneumonia and neonatal inclusion conjunctivitis through the cervix infected with Chlamydia trachomatis. In rare cases, Chlamydia trachomatis can also cause respiratory tract infections in immunodeficient adults, even community-acquired pneumonia in normal adults.

　　Combined with conjunctivitis, myocarditis, etc.

　　1, Conjunctivitis:The manifestations of inflammatory reactions caused by the action of Chlamydia trachomatis include foreign body sensation, burning sensation, eyelid heaviness, increased secretion, and when the lesion involves the cornea, it may cause photophobia, lacrimation, and varying degrees of vision loss.

　　2, Myocarditis:The inflammatory lesions of the myocardium caused by Chlamydia trachomatis have varied clinical manifestations. Mild patients may have no symptoms, while severe patients may experience heart failure, cardiogenic shock, or sudden death. Some patients may develop dilated cardiomyopathy changes after the acute phase, which can lead to recurrent heart failure.

　　Chlamydia trachomatis neonatal pneumonia is mainly seen in newborns and infants aged 2 to 12 weeks, most of whom have no fever. The initial symptoms are usually rhinitis, accompanied by mucous secretion and nasal congestion, followed by intermittent cough, tachypnea, and audible lung rales. It can be accompanied by myocarditis and pleural effusion. Half of the children may have acute inclusion conjunctivitis. Adult immunosuppressed patients may have pharyngitis, bronchitis, and pneumonia, etc., respiratory tract infections, with dry cough, fever, myalgia, chills, hemoptysis, and chest pain. Chest X-ray shows interstitial infiltration, and bronchopneumonia or reticular, nodular shadows may also be seen.

　　If pregnant women have Chlamydia trachomatis reproductive organ infection, prenatal treatment is the best method to prevent neonatal infection. Erythromycin is non-toxic to the fetus and can be used for treatment, as well as ethyl succinate erythromycin. After the newborn is born, erythromycin ointment should be applied immediately to effectively prevent conjunctivitis; if asymptomatic, a chest X-ray should be performed at 3 weeks after birth to exclude subclinical chlamydial pneumonia in infants and young children.

　　The most reliable method for Chlamydia trachomatis culture is to culture the specimen from nasopharynx or posterior pharyngeal wall swabs, tracheal and bronchial aspirates, alveolar lavage fluid, etc. For neonatal Chlamydia trachomatis pneumonia, conjunctival scraping material culture and (or) direct fluorescent assay (DFA) for Chlamydia trachomatis can be performed simultaneously, and the isolates can be identified using Chlamydia trachomatis species-specific monoclonal antibodies.

　　Using PCR tests to detect the above specimens is very helpful for diagnosis, but quality control must be ensured to prevent false positive results.

　　Microimmunofluorescence assay (MIF) is the standard and most commonly used serological diagnostic method for Chlamydia trachomatis internationally, especially suitable for the diagnosis of Chlamydia trachomatis pneumonia in newborns and infants, as it can detect the presence of high levels of non-maternal IgM antibodies (not crossing the placental barrier) in the child's serum. The serological diagnostic criteria are: MIF test IgG≥1:512 and (or) IgM≥1:32. After excluding false positives caused by rheumatoid factor (RF), recent infection can be diagnosed if the titer of serum antibodies increases by 4 times or more. Double serum antibody titer increases by 4 times or more can also be diagnosed as recent infection.

　　Pulmonary X-ray shows interstitial infiltration, and bronchopneumonia or reticular, nodular shadows can also be seen.

　　What foods are good for Chlamydia trachomatis pneumonia

　　Diet should be light, with an emphasis on vegetables and fruits, reasonable dietary搭配, and attention to adequate nutrition.

　　(The above information is for reference only, please consult a doctor for details.)

　　1. Treatment

　　The treatment of Chlamydia trachomatis pulmonary infection mainly includes oral erythromycin or tetracycline (not used for pregnant women and children), with a dosage of 40mg/kg of erythromycin per day for newborns and infants, or 40mg/kg of erythromycin ethylsuccinate per day. Alternatively, sulfisoxazole (sulfadimethoxazole) can be used at a dosage of 100mg/kg per day, with a course of 2-3 weeks. The dosage of erythromycin or tetracycline for adults is 2g/d, with a course of 2 weeks; or amoxicillin (500mg per dose, 2 times a day), doxycycline (100mg per dose, 2 times a day) can be used for treatment, with a course of 1-2 weeks; or ofloxacin 300mg per dose, 2 times a day, with a course of 1 week. For mild infections, a single dose of azithromycin 1g is also effective.

　　2. Prognosis

　　Chlamydia trachomatis infection often forms scars, and can also cause inverted eyelashes, entropion, corneal ulcers, and other conditions. Chlamydia trachomatis pneumonia can usually gradually heal spontaneously after a few weeks without treatment.