The disease belongs to the group of acute bacterial arthritis caused by streptobacillus (Streptobacillus moniliformis; streptobacillosis, or Heyverhillian fever) and spirochetes (Spirillum minus; cortex), found in the nasopharynx in half of healthy rats, as well as in mumps and protein.
Infection occurs when the animal bites (often in the foot) or during laboratory work, as well as in the game with a domestic rat.
The pathogen penetrates the human body through scratches, microtraumas. It is also possible to infect rats with feces on foods, water (more often in warehouses, less often in stores, canteens and food industry enterprises).
Usually, the infection spreads through lymphatic vessels, causing inflammation (lymphangitis) and lymph nodes (lymphadenitis).
When the infection penetrates into the blood, it spreads through the internal organs and stays in them. Subsequently, there is a recurrence of infection - recurrence.
The disease is found both in children and adults, is not transmitted from person to person.
The main manifestations of the disease from the bite of rats
The incubation period lasts from one day to three weeks. Already in the first days of the disease there is a fever with headache, nausea and vomiting, photophobia, as well as a spotty-papular (or urticular) rash.
Sometimes (in 25% of cases) the disease occurs without skin eruptions, but possible inflammation, infiltration and even ulcers in the bite or scratch area (the entrance gate of the infection). At the same time there are severe pains in the joints and muscles, and peripheral lymph nodes may increase.
Arthritis occurs acutely or subacutely, affecting one or several joints of the extremities (both small and large, with synovitis).
Often the internal organs are involved in the process, and the disease can be characterized by pneumonia, pancreatitis, prostatitis, heart disease (endo- peri, and myocarditis) with valve device damage and high (up to 50%) mortality.
In some cases, abscessation of the internal organs, including the spleen and the liver (with accompanying jaundice), as well as soft tissues and the brain, which is already regarded as a complication of the disease develops.
The course of the disease
Without treatment, a protracted course with periodically occurring fever and aggravation of arthritis may occur. In severe cases, with the development of complications, mortality reaches 6-10%.
When diagnosed with a bite, the diagnosis of the disease is often posed immediately, and in the absence of it, it is necessary to carry out the following additional studies:
- Bacterial cultures of blood and/or synovial fluid, rarer - ascitic fluid for the excretion of the pathogen;
- Isolation and microscopy of the pathogen when puncturing the material from the lymph nodes, abscesses, etc.;
- Serological examination of blood, synovial fluid (from the second week of the disease), in half of patients may be false-positive reaction to syphilis;
- General blood test (increase in ESR, leukocytosis);
- X-ray of joints most often does not detect changes, but at the ultrasound of joints signs of bursitis and synovitis are possible.
Treatment of arthritis in case of illness from bite of rats
- Immobilization of the patient, bed rest;
- Analgesics, non-steroidal anti-inflammatory drugs are used to relieve pain and inflammation;
- Intensive and prolonged antibacterial therapy (benzylpenicillin, streptomycin, tetracycline);
- Removal of purulent or serous contents from the patient's joint (puncture, arthrocenthesis).