Bites, Human

[Infect Dis Clin N Am 2021;35:219-36; Clin Infect Dis 2014;59:e10-52]

 

- Irrigation and debridement necessary.

- Immobilization and wound elevation, if possible, are beneficial.

- HIV and Hepatitis B & C have very rarely been transmitted by human bites. Assessment of risk factors and relevant management should be considered.

- Risk factors for developing osteomyelitis:

  • delay in initial treatment

  • inadequate debridement

  • primary closure of wound.

- Cloxacillin, cephalexin/cefazolin, clindamycin, and macrolides NOT effective against Eikenella spp.

- Pus/deep wound cultures recommended in established infections.

 
Usual Pathogens
Polymicrobial:

Streptococcus spp
Staphylococcus spp/MRSA
Anaerobes
Eikenella spp
Haemophilus spp
Corynebacterium spp

Prophylaxis

 Infection rate up to 50%. Prophylaxis within 12 hours of bite is recommended if:

  • moderate/severe (wound > 3 cm)
  • edema, pre-existing or resultant
  • bone/joint involvement
  • hand or face injuries
  • asplenic patients
  • advanced liver disease
  • immunocompromised
  • implants (e.g. prosthetic heart valves).
Empiric Therapy Dose Duration
Amoxicillin-clavulanate 875mg PO bid 3-5 days

Penicillin/amoxicillin allergy

Empiric Therapy

Dose

Duration
Cefuroxime axetil 500mg PO bid 3-5 days
+    
Metronidazole 500mg PO bid  

Cefuroxime allergy

Empiric Therapy

Dose

Duration
[Doxycycline 100mg PO bid 3-5 days
+/-    
Metronidazole]  500mg PO bid  
or    
[TMP/SMX 1 DS tab PO bid 3-5 days
+    
Metronidazole]  500mg PO bid  

Treatment

Empiric Therapy

Dose

Duration
Amoxicillin-clavulanate 875mg PO bid 7-10 days

Penicillin/amoxicillin allergy

Empiric Therapy

Dose

Duration
Cefuroxime axetil 500mg PO bid 7-10 days
+    
Metronidazole 500mg PO bid  

Cefuroxime allergy

Empiric Therapy

Dose

Duration
[Doxycycline 100mg PO bid

7-10 days

+/-    
Metronidazole]  500mg PO bid  
or    
[TMP/SMX 1 DS tab PO bid 7-10 days
+    
Metronidazole]  500mg PO bid  

Moderate

Empiric Therapy

Dose

Duration
Ceftriaxone 2g IV daily

7-10 days

+    
Metronidazole 500mg PO bid  

Severe/Limb-threatening

Empiric Therapy

Dose

Duration
Piperacillin-tazobactam 3.375g IV q6h 10-14 days
Penicillin allergy    
Meropenem 500mg IV q6h 10-14 days