In addition to the acute risk for localized infection, human bites pose the potential for the transmission of systemic infections, which can be life threatening. Hepatitis B transmission via human bites is well documented. In approximately 75% of patients with hepatitis B, the antigen is detectable in their saliva, and it is approximately 100 times more infectious than HIV.
Human bite wounds occur as two separate entities: clenched-fist injuries and occlusive bites. Clenched-fist injuries are the most common and have the greater clinical significance. They occur as the closed fist strikes the teeth of another individual with sufficient force to create a small wound, usually 3-8 mm in length. The injury usually occurs over the dorsal surface of the third and fourth metacarpophalangeal (MCP) or proximal interphalangeal joints of the dominant hand. Because of the thinness of the skin in these areas, potential injuries include joint penetration, metacarpal fracture, and extensor tendon laceration. Injury to the digital nerve or artery is rare. Clenched-fist infections are predominantly found in men, presumably owing to their more aggressive behavior. Occlusive bite wounds occur with equal frequency in males and females.
Regardless of the mechanism and anatomic location of the bite wound, the composition of the bacterial inoculum is the same. Cultures of human bite wounds are commonly polymicrobial in nature, and aerobes and anaerobes are represented almost equally. Beta-lactamase production occurs frequently. Commonly isolated aerobes include Eikenella corrodens and Staphylococcus, Streptococcus, and Corynebacterium species. Staphylococcus aureus is isolated in up to 30% of infected human bite wounds and is associated with some of the most severe infections.
For more on the etiology of human bite wounds, read here.
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Cite this: Richard H. Sinert. Fast Five Quiz: Test Your Knowledge on Key Aspects of Human Bite Wounds - Medscape - Apr 02, 2018.