[Bite injuries of the hand]

[Bite Wounds Should not be Irrigated by Syringe. An Anatomic Study]

In the literature about treatment of animal and human bite injuries, it is often recommended that bite wounds should be cleaned with a syringe and button cannula or plastic catheter. This is supposed to clean deeper wound sections and remove contamination and foreign bodies. Recent papers recommend cautious irrigation without high pressure.

MATERIAL AND METHOD

 In eight cadavers, artificial bite wounds were produced in typical locations. These wounds were irrigated by syringe and button cannula using diluted ink. The pressure of irrigation was limited to "no noticeable pressure".

RESULTS

 In all cases, more than half of the irrigation volume remained inside the victim´s organism, following anatomic structures and spreading over large areas.

CONCLUSION

Irrigation fails to clean the wound but increases the risk of contaminating the surrounding structures. Hence, the authors recommend that bite wounds should not be irrigated by syringe and button cannula.

Canibacter oris - a fairly unknown pathogenic agent of bite wound infections

Here, we report on the second case of bite wound infection by Canibacter oris. This bacterium belongs to the family of Microbacteriaceae in the order of Microbacterales in the class of Actinobacteria, which are prevalent in the oral flora. Possibly this bacterium has been overlooked until now, because it cannot be recognized by conventional differentiation methods. MALDI-TOF as well as PCR are able to identify this pathogen.

[The assessment of bite injuries from a forensic point of view]

The identification of a bite injury and its differentiation between human and animal origin demand a high level of special knowledge from the examining physician. The evaluation of bite injuries in terms of their hazard potential, risk profile and origin is usually done by a forensic specialist based on medical record documentation after immediate medical treatment. Therefore, as a first responder, a detailed documentation of the entire injury pattern is essential. If necessary, samples for further DNA analysis should be taken.The present article is intended to give a brief introduction to various aspects of bite injuries as well as to point out possibilities and limitations of the assessment of such cases.

Bite injuries to the hand: microbiology, virology and management

Bites to the human hand, be it from a pet, a stray animal or even a fellow human, may often have dire consequences for the person suffering the insult. Bites by mammals are a common problem and they account for up to 1% of all visits to hospital emergency rooms, in the UK. Clenched fist injuries to the mouth ('fight bite') are notorious for being the worst human bites. Bite injuries of the hand and their related infections must be monitored vigilantly and managed proactively, by experts in this field of surgery. In this review article we discuss the associated microbiology and virology of these injuries as well as their management.

Prevention of post-operative infections after surgical treatment of bite wounds

After reviewing the literature about the microbial spectrum, the risk factors of post-operative infections, and the results of surgical interventions, the following recommendation can be made for the management of bite wounds:

fresh, open wounds: surgical debridement, if appropriate, then an antiseptic lavage with a fluid consisting of povidone iodine and ethanol (e.g., Betaseptic^®), no antibiotics, primary wound closure

nearly closed fresh wounds (e.g., cat bites): surgical debridement, if appropriate, dressing with an antiseptic-soaked compress for ~60 minutes with repeated soaking (e.g., Betaseptic^®), no antibiotics

older wounds after ~4 hours: surgical debridement, if appropriate, dressing with an antiseptic-soaked compress or bandage for ~60 minutes with repeated soaking (e.g., Betaseptic^®), at the same time intravenous or dose-adapted oral antibiotics (Amoxicillin and/or clavulanic acid)

older wounds after ~24 hours: surgical debridement, then antiseptic lavage (Betaseptic^®), in case of clinically apparent infection or inflammation surgical revision with opening of wound and treatment with antibiotics according to resistogram (empirical start with Amoxicillin and/or clavulanic acid).

For each kind of bite wound, the patient’s tetanus immunization status as well as the risk of exposure to rabies have to be assessed. Similarly, the possibility of other infections, such as lues (Syphilis), hepatitis B (HBV), hepatitis C (HBC), hepatitis D (HDV) and HIV, in the rare case of a human bite wound, has to be taken into account.