Animal Bite-associated Infections

Microbiology and Treatment

Nicole Thomas; Itzhak Brook


Expert Rev Anti Infect Ther. 2011;9(2):215-226. 

In This Article

Rodent Bites

Infection occurs in up to 10% of rodent (i.e., rats, mice, guinea pigs, hamsters) bites. The most commonly associated disease is rat bite fever. This is due to either Spirillum minus or Streptobaccilus moniliformis, a fastidious organism that is difficult to isolate in culture. Symptoms include fever, rash and arthritis that remit and relapse without therapy.[47] This triad of symptoms may sometimes be incorrectly diagnosed as rheumatoid arthritis, thus delaying appropriate treatment.[48]

In the classic presentation, the arthritis is believed to be immune mediated, however it has recently been shown that S. moniliformis may also be associated with actual infective arthritis, especially in patients with underlying joint abnormalities.[49]

Serious complications such as endocarditis may also occur, and mortality may be as high as 53%.[50] Most cases are due to rat bites, but other rodents have been implicated.[51] Effective antibiotic therapy for rat bite fever includes PCN or doxycycline.

Other bacteria found in rat bite wounds include Staphylococcus, Leptospira, Pasteurella, Corynebacterium and Fusobacterium spp.[52,53]


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