Up to 1 percent of patients visit an emergency department because of a mammalian bite, usually from a pet or familiar animal. The use of antibiotics to prevent infection of the bite wound is controversial. The few studies focusing on the efficacy of antibiotic prophylaxis for bite wounds have suffered from small participation numbers and low infection rates. Turner conducted a systematic review of published studies to examine the efficacy of antibiotic prophylaxis in preventing infections following mammalian bites.
The review included eight published randomized or quasi-randomized studies. The studies involved patients with bite wounds who received antibiotics, placebo, or no intervention within 24 hours of the injury and had no evidence of infection at the start of treatment. The authors noted the incidence of subsequent infection, defined by clinical signs and microbiologic cultures.
Prophylactic antibiotics provided a significant reduction in infections after human bites but not after cat or dog bites. The type of wound did not influence the infection rate in patients receiving antibiotics. However, the infection rate of hand bites was reduced significantly from 28 to 2 percent after antibiotic prophylaxis.
The authors conclude that insufficient evidence exists to support antibiotic prophylaxis in dog and cat bites, and minimal evidence supports its use for human bites. However, there is evidence that antibiotics reduce the risk of infection in hand bites.