neonatal chlamydia infection
Introduction
Introduction to Chlamydia infection in newborns Chlamydia trachomatis can infect the cervix of pregnant women and infect newborns through the birth canal of infected mothers, causing conjunctivitis and pneumonia in newborns. Chlamydia is a pathogenic microorganism similar to bacteria. basic knowledge The proportion of the disease: 0.0004%, more common in the mother with chlamydial infection urethritis Susceptible people: children Mode of transmission: vertical transmission of mother and baby Complications: Chlamydia pneumonia
Cause
Neonatal chlamydia infection cause
(1) Causes of the disease
The source of infection of chlamydial infection is patients and carriers. The transmission route mainly passes through sexual life and contact with the eye secretions of infected people. Most of the infections of newborns are derived from the birth canal during childbirth, and the detection of female genital chlamydia is often positive.
(two) pathogenesis
After invading the human body, Chlamydia (primary corpuscle) first attaches to the outer membrane receptor on the surface of the host epithelial cell, and enters the cell through the phagocytosis of the cell. After entering the cell, the volume of the original corpuscle increases into a reticular body, relying on the nutrition of the host cell. The substance, in a splitting manner, proliferates into a new primitive body and forms an inclusion body containing a plurality of primitive bodies, and finally the inclusion body membrane swells, releasing the original body and then diffusing and infecting adjacent epithelial cells. Chlamydia parasitic in the host cell can directly inhibit the metabolism of the host cell, dissolve the parasitic cells, release lysozyme and various metabolites, and stimulate the body's immune response to cause damage. Because the body has weak specific immunity against Chlamydia, the duration is short, so Chlamydia is prone to repeated infections.
Prevention
Neonatal chlamydial infection prevention
Since chlamydia has become the first pathogen of sexually transmitted diseases in the world today, it is necessary to strengthen the examination of chlamydia in pregnant women's reproductive tract secretions, timely detection and early treatment to prevent the occurrence of neonatal inclusion body conjunctivitis and chlamydia pneumonia.
1. Prenatal routine screening: The most important preventive measure is prenatal routine screening for chlamydia. Timely treatment of pregnant women with infection can effectively improve pregnancy outcomes (reducing the incidence of miscarriage, premature delivery, premature rupture of membranes) and The infection rate of chlamydia in newborns.
2. Treatment of chlamydia during pregnancy: can significantly reduce the incidence of premature delivery, premature rupture of membranes, low birth weight infants.
3. Caesarean section: Newborns can cause conjunctivitis and pneumonia when they pass through the mother's birth canal of chlamydia, and cesarean section can significantly reduce the incidence (except for premature rupture of membranes).
Complication
Newborn chlamydial infection complications Complications Chlamydia pneumonia
Neonatal inclusion body conjunctivitis and chlamydia pneumonia occur mainly.
Symptom
Symptoms of Chlamydia infection in neonates Common symptoms Low fever snoring Lung infections Breathing difficulties Purulent discharge Conjunctiva Congestion Premature rupture of membranes
In most cases, Chlamydia trachomatis infects the eyes, nasopharynx, cervix, urethra and rectal mucosa. Chlamydia trachomatis can affect the columnar epithelial cells of the cervix in pregnant women, rarely involving vaginal squamous epithelial cells, and can retrograde infection in the uterus. Membrane, damage to the embryo, can cause stillbirth, premature delivery, premature rupture of membranes, etc. Newborns can cause conjunctivitis and pneumonia when infected with chlamydia through the mother's birth canal.
1. Conjunctivitis: about 30% to 50% of neonates born to infected mothers will develop conjunctivitis, 10% to 20% will develop pneumonia, conjunctivitis often occurs 5 to 14 days after birth, often unilateral onset, There are many self-limiting factors, first catarrhal conjunctivitis symptoms, followed by mucopurulent secretions, swelling of the eyelids and membranes, congestion, eyelids and membrane follicle formation are rare in newborns.
2. Nasopharyngeal infection: About 50% have a nasopharyngeal infection.
3. Pneumonia: occurs more than 1 to 3 months after birth, 25% with nasopharyngeal infection, manifested as cough (canine-like), shortness of breath, no heat and low fever, both lungs wet voice, heavy breathing Difficulties and cyanosis, wheezing is not obvious, different from pneumonia caused by respiratory syncytial virus, X-ray examination of interstitial infiltration of both lungs, eosinophilia >400/mm3.
4. Others: Infections in other parts, such as vaginal and rectal infections, are more invisible and less noticeable.
Examine
Examination of neonatal chlamydial infection
Chlamydia infection or a latent infection or clinical symptoms are non-specific, so the diagnosis of this disease depends on laboratory tests.
1. Direct examination of the microscope: the swab or scraper secretion on the mucosal surface to find the inclusion body and the original body of the chlamydia.
2. Tissue cell culture separation of Chlamydia: Take the combined membrane specimen or bronchoalveolar lavage fluid for cell culture to isolate Chlamydia, the specificity is high, but the conditions are more demanding and the operation is cumbersome.
3. Chlamydia antibodies: Serum or secretions Chlamydia antibodies are the most widely used.
(1) Immunofluorescence test: Microimmuno fluorescence test (MIF) is mainly used for the diagnosis and stereotyping of Chlamydia trachomatis.
(2) Enzyme-linked immunoassay EIA: sensitivity 80% to 90%, specificity > 95%.
(3) PCR method: compared with traditional tissue cell culture, the sensitivity is up to 90% and the specificity is up to 99%.
4. Blood: Eosinophilia > 400 / mm 3 .
5. Chest X-ray examination: Interstitial infiltration of both lungs, long duration, X-ray see high brightness of both lungs, extensive, varying degrees of interstitial and alveolar infiltration, focal atelectasis.
6. B-ultrasound: check for hepatosplenomegaly and so on.
Diagnosis
Diagnosis and diagnosis of neonatal chlamydial infection
Diagnosis is based on medical history, clinical presentation, and laboratory tests.
Laboratory diagnosis can take nasopharyngeal, tracheal aspirate and lung biopsy specimens for chlamydia culture, antigen detection and PCR detection, serum anti-Chlamydia antibody titer, can help the diagnosis of acute infection, with micro-immunofluorescence or enzyme immunoassay Determination of anti-Chlamydia IgM, such as > 1:32 is highly suggestive of chlamydia pneumonia, such as limited laboratory conditions, according to suspicious clinical manifestations, combined with chest X-ray, blood eosinophil count, serum IgG, IgM examination, if necessary Diagnosing the disease can be done by doing bacterial culture to rule out other infections.
Chlamydia pneumonia should be differentiated from pneumonia caused by other pathogens, such as respiratory syncytial virus, cytomegalovirus, adenovirus and influenza virus, resulting in non-pyrogenic pneumonia; Streptococcus, Staphylococcus aureus, Escherichia coli, Cray Pneumonia, tuberculosis, etc. caused by white bacilli, influenza bacilli, pneumococcal and meningococcus.
