Group B streptococcal infection
Introduction
Introduction to B streptococcal infection It has been reported that according to observations in the United States, the infection rate of B-streptococcus is increasing, and the reason is still unclear. In recent years, neonatal infections caused by this group of bacteria have been reported many times, which has attracted people's attention. According to the difference of surface antigens, it can be divided into nine subtypes, namely Ia, Ib, II, III, IV, V, VI, VII and VIII. On the blood plate, there may be a type A, type B or type C hemolytic reaction. The streptolysin produced by the hemolytic strain is different from the group A by the O and S, and has no antigenicity. According to the biochemical classification method, the group is not S. agalactiae. basic knowledge The proportion of sickness: 7.9% Susceptible people: no specific population Mode of infection: non-infectious Complications: pneumonia sepsis
Cause
Causes of infection with B streptococcus
(1) Causes of the disease
B streptococcal infection accounts for about 8% of all streptococcal infections, and can be divided into nine subtypes according to different surface antigens, namely Ia, Ib, II, III, IV, V, VI, VII and VIII. It may be in a type A, B or C type hemolysis reaction. The streptococcal hemolysin produced by the hemolytic strain is different from the O and S of the group A, and has no antigenicity. According to the biochemical classification method, the group is Streptococcus agalactiae. (S.agalactiae).
(two) pathogenesis
Group B streptococci can be colonized in the vagina, intestines and urethra of pregnant women, newborns can be directly from the mother, or by the maternal genital tract colonization during childbirth. In group B, streptococcal infection is rare in adults, to maternal Mainly, in a few cases, patients with low immune function, such as diabetes, chronic liver dysfunction, HIV infection, malignant tumors receiving immunosuppressive therapy, etc. can also be infected with group B streptococcal disease.
Prevention
B streptococcal infection prevention
There have been many reports of neonatal infections caused by this group of bacteria, which has attracted people's attention. Neonatal infection pathogens mainly come from maternal vaginal carrier rate of 4.6% ~ 25.4%, early water breakage or prolonged labor are easy to lead to neonatal infection. Secondly, the hospital staff carrying the bacteria threatened the newborn. It has been reported that the rate of nasopharyngeal infection in male staff of the hospital is 15.8%, and that of female workers is 23.2%. The incidence of neonatal infection caused by this group of bacteria is 1.35/1000~5.4/1000. The infection of B-streptococcus in adults with live birth occurs mostly when the body's resistance is low. Causes: Streptococcal infection accounts for all streptococcal infections. About 8%. According to the difference of surface antigens, it can be divided into nine subtypes, namely Ia, IbII, III, IV, V, VI, VII and VIII. The blood plate may be in a type A, B or C type hemolysis reaction, and the streptolysin produced by the hemolytic strain is different from the O and S of the group A, and has no antigenicity. According to the biochemical classification, this group of bacteria is the pathogenesis of S. agalactiae: Group B streptococci can be colonized in the vagina, intestines and urethra of pregnant women, newborns can be directly from the mother or childbirth The maternal genital tract colony is infected. In group B, streptococcal infections in adults are rare, mainly in women. In a few cases, those with low immune function, such as diabetes, chronic liver dysfunction, HIV infection, malignant tumors, immunosuppressive therapy, etc., can also infect group B streptococci. disease.
Complication
B streptococcal infection complications Complications pneumonia
pneumonia:
Inflammatory lesions in the alveolar and interstitial lungs. There is fever, shortness of breath, persistent dry cough, chest pain during deep breathing and coughing, and a small amount of sputum or a large amount of sputum. Children with pneumonia, symptoms are often not obvious, may have a mild cough or no cough at all. Should pay attention to timely treatment.
Urinary system infections:
Common urethritis, cystitis, vaginitis.
Soft tissue infection:
The tissue has red, swollen, painful symptoms or purulent inflammation.
septicemia:
A serious infection of the whole body. Clinical manifestations include fever, severe toxic symptoms, rash rash, hepatosplenomegaly, and increased white blood cell count.
Symptom
B streptococcal infection symptoms Common symptoms Pulmonary infection abscess septic meningitis bacterial infection
Can be divided into two types of neonatal infections and adult infections.
1. Early onset is caused by bacterial infection in the birth canal. The disease occurs within 7 days after birth, and is often manifested as pulmonary infection, sepsis and meningitis. Early onset occurs when respiratory distress occurs, and the mortality rate is high. It is often between 50% and 80%, and there are more type II bacteria in the dead.
2. Late onset is mostly caused by maternal postpartum complications, occurring within 7 to 30 days of birth, with sepsis and meningitis being more common, the type of bacteria is more type III, especially meningitis, more than 90% are caused by type III The mortality rate is lower than that of the early onset, and the mortality rate of meningitis is about 14%.
3. Young women are prone to gynecological examination, pregnancy and delivery, and are prone to urinary tract infection and endometritis of B-streptococcus, pneumonia, meningitis, liver abscess, sepsis, etc., older, especially suffering Some people with chronic diseases, both men and women can be infected, and those who have received antibiotics or hormones and other immunosuppressive agents for a longer period of time, the mortality rate is higher, it is reported to be 29% to 52%, according to Schlievert et al. The clinical manifestations of patients with TSLS were only cultured with B streptococcus and no group A streptococci and staphylococci. A pyrogenic toxin was proposed from bacterial cultures and did not interact with anti-TSLS-1 and anti-SPE antibodies. It is suggested that group B bacteria also produce toxins that cause TSLS.
Examine
Examination of B streptococcal infection
The B-streptococcus antigen in urine has a high positive rate, blood culture, and bacteria-positive.
Diagnosis
Diagnosis and identification of B streptococcal infection
It relies mainly on bacterial culture, and Ingran reports that latex agglutination tests can be used to detect early patients.
Clinical should be differentiated from group A streptococcal infection.
