antibacterial and antiviral prescribing following bite wounds

Last edited 07/2021 and last reviewed 11/2023

• antibacterial prophylaxis:
  • prophylactic antibacterial therapy should be offered to patients who:
    • sustain bites to the hand, or from humans or cats
    • antibacterial prophylaxis is a reasonable precaution when the wound involves moderate or severe injury, or crush or puncture injury; when oedema is present; when bone or joint penetration is possible; when a bite injury to the face has been closed; when the genital area is involved; for complicated dog bites (e.g. those requiring surgical debridement); for patients who are immunosuppressed, have diabetes or prosthetic heart valves; or where the injury is near a prosthetic joint (1)
    • PHE guidance states (2):
      • human bite
        • assess risk of tetanus, HIV, hepatitis B&C
        • antibiotic prophylaxis is advised
      • animal bite
        • assess risk of tetanus and rabies
        • give antibiotic prophylaxis if cat bite/puncture wound; bite to hand, foot, face, joint, tendon, ligament; immunocompromised/diabetic/asplenic/cirrhotic/ presence of prosthetic valve or prosthetic joint
          
          
  • which antibiotic:
    • co-amoxiclav (625mg three times daily for adults) is the antibacterial of choice for initial prophylaxis, or the treatment of established infection, before culture and sensitivity results are available
      • if penicillin allergic (2):
        • metronidazole PLUS doxycycline (cat/dog/man) or
        • metronidazole PLUS clarithromycin (human bite)
        • review at 24 and 48 hours (2) - because the recommended regimen covers the majority, but not all, of the likely pathogens from an animal or human bite
          
          
• antiviral prophylaxis:
  • human bites
    • a risk assessment should be made and, where appropriate, hepatitis B vaccine and/or specific hepatitis B immunoglobulin and/or HIV post-exposure prophylaxis should be offered
    • there is no post-exposure prophylaxis for hepatitis C, which appears to be transmitted more easily than HIV. However, a patient exposed to hepatitis C will need sequential tests for seroconversion, and appropriate referral

NICE have suggested a schemata for managing human and anima bites (3):

Reference:

1. Drug and Therapeutics Bulletin (2004);42:65-72
2. Public Health England (October 2014). Management of infection guidance for primary care for consultation and local adaptation
3. NICE (November 2020). Human and animal bites: antimicrobial prescribing