Complaints about bitten wounds are quite common in ambulatory surgical practice. Stitch wounds are usually contaminated with various microorganisms, which can lead to an infectious process and, in the absence of medical care, the development of complications such as local abscess, osteomyelitis, septic arthritis, meningitis, abscesses and sepsis removed. The infection is more severe in patients with immunodeficiency conditions.

Here are the main characteristics of injuries caused by the bites of various mammals.

Injuries after a person's bite can occur during physical abuse (for example, when the skin is damaged by the teeth when it hits the jaw) and during sexual intercourse (the so-called "love bites") ). The bites are located mainly on the fingers or hands, less often in the neck, chest and genitals. About 30% of hand abrasions caused by a blow to the teeth are accompanied by deep damage and the development of infections of the ligament and bone, especially with late medical assistance (after 24 hours). The bacteria that contaminate the wound are streptococci, Staphylococcus aureus, Homophiles spp., Fusobacterium spp., Bacteroids and other anaerobes, as well as Eikenella corrodens. Infection with viruses, such as hepatitis B virus, hepatitis C virus and HIV, is much less common.

Wounds after dog bites are contaminated with the microflora of the oral cavity of these animals, usually including pathogens such as Pasteurella spp., Streptococci, staphylococci, anaerobic bacteria and, in 2 to 30% of cases are accompanied by the start of an infection. Capnocytophaga canimorsus, a Gram-negative bacillus that occasionally infects dog (and cat) bites, can lead to the rapid development of life-threatening septic syndrome, particularly in immunocompromised individuals. When bitten by a stray dog, it is necessary to remember the possibility of a rabies infection.

Cat bites are most often represented by puncture wounds, which complicates their treatment. The damage is localized mainly on the hands and forearms and in 2/3 of the cases is accompanied by the development of an infection. In approximately 75% of cases, the infection is caused by Pasteurella spp., Among other pathogens, a wide range of aerobic and anaerobic microorganisms. Cat scratch disease can occur at the site of a bite or scratch caused by a cat or dog. The infection is caused by Bartonella henselae and is manifested by the appearance of an erythematous papule (usually 3 to 10 days after the injury), regional lymphadenitis and general symptoms of infection. The disease is resolved after 2 months, however, in some cases it can be complicated by the development of pneumonia, encephalitis or hepatitis, rarely a pathology of the organ of vision.

The bites of small rodents such as mice, rats, hamsters and guinea pigs can be contaminated with a number of microorganisms, including representatives of Pasteurella spp. and Streptobacillus moniliformis (causes "rat bite fever"). A protein bite is thought to lead to a typhoid or tularaemia infection.

Bites from horses, donkeys, pigs and sheep can be infected with Acinetobacillus spp., Pasteurella spp., Staphylococci, streptococci and anaerobic bacteria. Ferret bites are contaminated with Staphylococcus aureus. With the bite of bats, rabies is transmitted. Camel stings cause infection with representatives of Pseudomonas spp., Staphylococci and streptococci, as well as Clostridium tetani. Monkey bites are mainly infected with bacteroids, fusobacteria, staphylococci, streptococci and E. corrodens. With the bite of macaques, the herpes B virus (Herpesvirus simiae) can be transmitted, leading to the development of a rapidly progressing encephalomyelitis, with a mortality rate of up to 70%.

During the initial treatment, an anamnesis is taken (bite time and type of animal), smears are taken for bacteriological examination and primary surgical treatment of the wound. In case of systemic signs of infection, a blood sample is also taken to identify aerobic and anaerobic pathogens. When the wounds are contaminated with soil, fragments of plants or water from ponds, lakes, aquariums, as well as in patients suffering from immunodeficiency, bacteriological tests for mycobacteria and fungi are carried out. When a person bites, there is also a need for testing for the hepatitis B virus and HIV infection. Other clinical and instrumental examinations are carried out according to the indications (for example, radiography or ultrasound in case of suspected bone, joint or presence of a foreign body in the wound).

The treatment of wounds consists of washing with saline or water, with superficial damage, it is possible to use antiseptics (hydrogen peroxide or povidone iodine). Closing the wound is recommended for cool processes (less than 6 hours) that are probably not infected, as well as for cosmetic purposes (on the face). Delayed wound closure (after 3-5 days) is used for bites lasting more than 6-8 hours, localized in the limbs and accompanied by crushing of the tissue.

The indications for hospitalization are fever, sepsis, progressive cellulitis, severe swelling or tissue damage, loss of limb function, patient's immunodeficiency, as well as infection with dangerous infections (e.g., Herpesvirus simiae), in which patients should be kept in quarantine.

The purpose of prophylactic antibacterial therapy is indicated for bites by humans, cats or complicated bites of dogs, as well as the localization of the process in the limbs, genitals and face, serious damage, involvement bones and joints in the pathological process, or the localization of a bite near a prosthetic joint and in patients with immunodeficiency states of various genesis.

The choice of an antibacterial drug is based on data from a bacteriological study. Until its results are obtained, the drug of choice is amoxicillin / clavulanate (625 mg 3 times a day for adults). If you are allergic to penicillins, you can prescribe metronidazole in combination with doxycycline for cat and dog bites. In human injections, metronidazole in combination with erythromycin can also be used, however, ciprofloxacin in combination with clindamycin is preferred. With a severe nature of the infection, antibiotics are administered intravenously, the duration of treatment depends on the clinical dynamics.

Preventive antiviral therapy (hepatitis B virus, HIV, rabies and Herpesvirus simiae) is used if it is suspected that infection may occur according to standard treatment regimens. Tetanus prophylaxis (tetanus vaccine and tetanus immunoglobulin) is done in the absence of a confirmed immunological history in the patient (i.e. routine tetanus immunoprophylaxis data and schedule). If there is a risk of contracting hepatitis or HIV, monitoring of patients should continue for at least 3 months.