Streptobacteriosis

Introduction to Streptococcus Rat-bitfever, a primitive infectious disease of rats, is an acute infectious disease caused by bites in rodents or other rodents. It is caused by irregular fever in the case of A. faecalis, and there are many arthritis and rashes. . basic knowledge The proportion of illness: 0.069% Susceptible people: no special people Mode of infection: rat bites Complications: bronchial pneumonia, lung abscess, orchitis

Cause of streptococcosis

Direct infection factors (45%):

The bite fever of the bacterium of the genus Streptomyces is caused by the bacterium of the genus Candida. In 1925, Levaditi et al. found the bacterium from the blood of the experimental staff and described it in detail as a rat biting fever pathogen, called the bead chain. Bacillus (streptobacillus moniliformis).

Indirect infection factors (35%):

In 1926, Place and Sutton et al. reported an outbreak of epidemics in the Haverhill area due to milk contamination, known as Haverhill fever, also known as epidemic erythematous arthritis, followed by Parker And Hulson isolated the pathogen from the blood of patients with Harvard Hill fever, in fact it has been clarified that it is caused by A. albicans, Harvard Hill fever is another infection of Streptococcus mutans Manifestations.

This bacterium is highly pleomorphic, aerobic, non-dynamic, non-spore, non-capsulated, heat-resistant, Gram-negative bacteria, and its morphological characteristics are closely related to its environment. The typical characteristics of the medium are short rods of 2 to 4 m, which can be arranged in a chain or filament shape of 15 to 150 m. The filaments are expanded in a bead shape, varying in length, sometimes curved and intertwined into a cluster, and the chain is stalked. Bacteria are aerobic or facultative anaerobic bacteria. They are not easy to grow in common medium. They must grow in a medium containing blood, serum or ascites, but growth is slow. It usually takes 2 to 7 days in growth period, at 5%. ~10% carbon dioxide, can promote its growth in 37 ° C environment, its colonies are white, morphologically pleomorphic, and has a velvety ball shape, diameter of one or two millimeters, the bacteria have the ability to automatically form and maintain L mutation, in In an unsuitable environment, it can be spontaneously converted into an L-form. In a suitable environment, it can automatically restore its intrinsic morphology. This L-type bacteria can invade the body tissues. Because L-type bacteria lack cell walls, penicillin and cell wall are affected. Antibiotics are not sensitive, give The treatment brings some difficulties, it is difficult to control the clinical symptoms in time. It is reported that the pathogen can still be isolated from the blood after 10 days. The bacteria is not strong enough to the outside world. It is killed at 55 °C for 30 minutes, sensitive to common chemical disinfectants, serum. The medium broth culture solution can be stored at 37 ° C for 1 week.

Pathogenesis

According to a few autopsy reports, the basic lesions are congestion, edema, monocytes and plasma cell infiltration of various organs, ulcerative endocarditis, liver, spleen, renal infarction, interstitial pneumonia, myocarditis, nephritis, Adrenitis, arthritis, etc., normal cells have degenerative changes, and a small number of bites have an inflammatory reaction.

Streptococcal disease prevention

Rodent control is the most important measure to prevent bites from being bitten by rats or other animals. Laboratory workers who are in contact with rats should pay attention to protection and wear gloves. In case of bite, except for local treatment, penicillin should be injected immediately.

Streptococcal complications Complications, bronchopneumonia, lung abscess, orchitis

Candida albicans can be complicated by pericarditis, bronchial pneumonia, lung abscess, orchitis, spleen, kidney infarction.

Streptococcosis Symptoms Common symptoms Back pain spots, papules, high fever, chills, freckles

The incubation period is generally 1 to 7 days. For up to 22 days, the bite is easy to heal, no indurated ulcer is formed, and the local lymph nodes are not swollen. After 1 to 22 days of incubation, sudden chills, high fever, headache, Back pain, vomiting, irregular heat or intermittent, relieved after 1 to 3 days, after the heat can rise again, but the regularity is not as good as the small snails bite heat, more than 50% of patients in the second week after the disease Sexual joint pain or arthritis, more common in the wrist, elbow and other joints, the affected joints have red, swollen, painful or see joint fluid effusion, 75% of patients with congestive rash within 1 ~ 8 days after fever, generally For the maculopapular rash, it is centrifugally distributed, often involving the palms and toes. It can also be measles-like, sometimes with sputum, ecchymoses or fusion into pieces. The rash can last for 1 to 3 weeks, and about 20% of the rashes appear after the rash. Acute phase can be complicated by bronchial pneumonia, lung abscess formation, orchitis, pericarditis, spleen, kidney infarction, the most common and serious complication is bacterial endocarditis, especially those with heart valve disease are more likely to occur, if there is no concurrent Symptoms occur, the disease lasts for 2 weeks and can automatically resolve Few sustainable without treatment or recurrent fever and arthritis, who occasionally persistent for several years, very few aftermath of joint movement disorders, skin rashes generally do not relapse, mortality was about 10%.

Harvard Hill fever, acute chills, high fever, similar to respiratory infections and acute gastroenteritis symptoms, more than 95% have irregular morphological and size rash and arthritis symptoms, the disease has a good prognosis, recurrence is very rare.

Examination of streptococcosis

1. General laboratory inspection

1 white blood cell count (10 ~ 30) × 109 / L, nuclear left shift, moderate anemia,

2 About 25% of patients have positive serum syphilis antibody,

3 The specific agglutination test titer reached 1:80 on the 10th day after the disease, and the highest titer was more than 4 times in the first 1-3 months after the disease. This agglutination antibody can last for more than 2 years, and the positive value can be used as an auxiliary diagnosis. However, the negative can not rule out the disease, fluorescent antibody and complement fixation test can also help diagnose.

2. Pathogen examination: acute phase blood, pus, joint cavity fluid culture can find pathogens, but generally conventional culture should not grow bacteria, add 20% horse or rabbit serum with broth or trypsin agar at 22 ~ 37 °C Interculture, for example, is more conducive to growth in a 10% carbon dioxide environment, and the mice are killed within 1 to 2 weeks of inoculation, and the blood contains pathogenic bacteria.

3. PCR detection: In recent years, the PCR method is used to detect the blood, pus and joint cavity fluid of acute phase patients with high accuracy and early diagnosis value.

The joint exudate is inoculated in a special medium to obtain a positive result.

Diagnosis and identification of streptococcosis

diagnosis

Mainly rely on a history of rat bites, fever, rash, polyarthritis and other clinical symptoms, sometimes without a history of rat bites, diagnosed with pathogen culture or animal inoculation to find pathogens.

Differential diagnosis

The differential diagnosis is first distinguished from the snail heat of the small spirulina. In addition, it is differentiated from rash caused by other causes, such as rubella, sepsis, cerebral palsy and drug rash. Harvard Hill fever should also cause diarrhea caused by other causes, respiratory tract. Identification of infection.

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