Approximately 10%-15% of human bite wounds become infected owing to multiple factors. The bacterial inoculum of human bite wounds contains as many as 100 million organisms per milliliter and is made up of as many as 190 different species. Many of these are anaerobes that flourish in the low redox environment of tartar that lies between human teeth or in areas of gingivitis. Most injuries due to human bites involve the hands. Hand wounds, regardless of the etiology, have a higher rate of infection than do those in other a locations. (See Pathophysiology and Etiology.)
Infections associated with human bites are often far advanced by the time they receive appropriate care. Patients often wait until infection is well established before seeking medical treatment. These wounds are frequently more extensive than estimated on initial examination by the inexperienced observer and are frequently managed inadequately. (See Prognosis, Presentation, Treatment, and Medication.)
Human bites have been shown to transmit hepatitis B, hepatitis C, herpes simplex virus (HSV), syphilis, tuberculosis, actinomycosis, and tetanus.
Evidence suggests that it is biologically possible, but quite unlikely, to transmit human immunodeficiency virus (HIV) through human bites. (See Pathophysiology, Presentation, and Workup.)