Animal or Human Bites in Adults - Prevention of Infection

Publication: 01/07/2009  --
Last review: 07/02/2022  
Next review: 07/02/2025  
Clinical Guideline
CURRENT 
ID: 1752 
Approved By: Improving Antimicrobial Prescribing Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2022  

 

This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Guideline for the treatment and prevention of infection following animal or human bites in adults

If cellulitis is already present see Guidelines for cellulitis and necrotizing fasciitis for antimicrobial and treatment recommendations

For patients admitted with an animal or human bite the following diagnostic tests should be taken to confirm management plans:

No microbiology investigations required if no signs of infection

X-ray if:

  • Suspicion of bony injury or penetrating joint injury or suspicion of retained radio-opaque foreign body (e.g. tooth).

Rarely tooth fragments may remain in bite wounds, particularly when high forces such as punch injuries or some dog bite injury occur. In the presence of deep or extensive bite injuries soft tissue x-rays may be required to exclude retained foreign body.

Consider referral to hand / plastic surgeons (upper limb bite) / orthopaedic surgeons (lower limb bite) if extensive wound or complex structures involved or if cosmetic concerns e.g. facial wounds. If there is doubt consult with a senior Emergency Department Clinician.

Back to top

Management

  • Immediate irrigation with copious amounts (at least 250ml) of sodium chloride 0.9% or sterile water. Visible contamination should be removed with forceps or scrubbing.
  • If debridement is likely to result in a significant tissue deficit which will compromise wound closure or cosmetic outcome referral should be made to plastic surgery.
  • Primary wound closure should not routinely performed except for bite wounds on the face. Rigorous cleansing and appropriate debridement must occur prior to any primary closure. Delayed primary closure should be considered at review at 48-72 hours. The presence of cellulitis or other obvious wound infection is a contraindication to delayed primary closure at that time.
  • Offer analgesia as appropriate (paracetamol or ibuprofen).

Back to top

Prophylaxis or treatment

Infected bite

Give antimicrobial treatment for a duration of 5 days

Non-infected bite

Give antimicrobial prophylaxis only if indicated below for a duration of 3 days

Type of bite

Bite has not broken the skin

Bite has broken the skin but not drawn blood

Bite has broken the skin and drawn blood

Human

Do not give antibiotics

Advise antibiotics if it is in a high-risk area1 or person at high risk2

Give antibiotics

Cat

Consider antibiotics if the wound could be deep

Give antibiotics

Dog or other traditional pet

Do not give antibiotics

Give antibiotics if it has caused considerable, deep tissue damage

Back to top

Prevention of transmission of assiciated infections

All bites

Tetanus

A tetanus toxoid booster should be administered for patients whose immunization schedule is not up to date, or whose immune status is unknown, and further doses given to complete the five-dose schedule.

In human bites:

  • If the bite has not broken the skin there is no risk of blood-borne virus transmission
  • If the bite has broken the skin, offer testing for Hepatitis B, Hepatitis C and HIV.

Hepatitis B

In human bites consider risk of transmission

HIV

In human bites consider risk of transmission

Animal Bites

Rabies: animal bites

There is no risk from bites acquired in the United Kingdom. Bites acquired overseas require a risk assessment. For bites that have originated outside of the UK, information can be sought from Public Health England's guidance on Rabies risks by country and Public Health England's Rabies and Immunoglobulin Service, PHE Colindale (tel. 020 8327 6204).

Rabies: bats

Advice should be sought from PHE, Virus Reference Department (VRD), Colindale, London (Tel: 020 8327 6017).

Back to top

Empirical treatment

Empirical options following an animal or human bite

Duration:
Prophylaxis = 3 days
Treatment = 5 days3

1st line

Co-amoxiclav electronic Medicines Compendium information on Co-amoxiclav  625mg PO 8-hourly

Alternative 1st line if penicillin allergy or co-amoxiclav unsuitable

Doxycycline electronic Medicines Compendium information on Doxycycline PO 200mg on day one then 100mg daily (increase to 100mg  twice daily in severe infection4)
AND
Metronidazole electronic Medicines Compendium information on Metronidazole PO 400mg 8-hourly

Alternative 1st line in pregnancy if penicillin allergy or co-amoxiclav unsuitable5

Azithromycin electronic Medicines Compendium information on Azithromycin PO 500mg daily
AND
Metronidazole electronic Medicines Compendium information on Metronidazole PO 400mg 8-hourly

1st choice IV antibiotics (if unable to take orally or severely unwell)

Co-Amoxiclav  IV 1.2g 8-hourly

Oral switch:
Co-Amoxiclav   625mg PO 8-hourly

Alternative 1st choice IV antibiotics for penicillin allergy or co-amoxiclav unsuitable.

If a cephalosporin is not suitable, seek specialist advice

Cefuroxime electronic Medicines Compendium information on Cefuroxime IV 750mg 8-hourly6
AND
Metronidazole electronic Medicines Compendium information on Metronidazole IV 500mg 8-hourly

Oral switch:
Non-pregnant patients:
Doxycycline electronic Medicines Compendium information on Doxycycline PO 100mg daily (increase to 100mg  twice daily in severe infection4)
AND
Metronidazole electronic Medicines Compendium information on Metronidazole PO 400mg 8-hourly

Pregnant patients:
Azithromycin electronic Medicines Compendium information on Azithromycin PO 500mg daily
AND
Metronidazole electronic Medicines Compendium information on Metronidazole PO 400mg 8-hourly

Back to top

Review by 72

NICE recommends that IV antibiotics given for treatment of bites should be reviewed within 48 hours and switched to an oral antibiotic if possible.

Please contact Microbiology if the patient is not responding to the recommended antimicrobial regimens.

FOOTNOTES

  1. High risk areas include the hands, feet, face, genitals, skin overlying cartilaginous structures or an area of poor circulation.
  2. People at high risk include those at risk of serious wound infection because of a co-morbidity (such as diabetes, immunosuppression, asplenia, or decompensated liver disease).
  3. Duration may need to be extended to 7 days if there is significant tissue destruction or the bite has penetrated bone, joint, tendon or vascular structures
  4. Severe infection defined as: evidence of spreading cellulitis, tissue damage or child systematically unwell.
  5. Choice for pregnant women taken from draft NICE guidance that formed final version of NG184 (see evidence)
  6. Cefuroxime dose can be increased to 750mg 6-hourly or 1.5g 6-8-hourly if infection is severe

Provenance

Record: 1752
Objective:
Clinical condition:

Animal or human bites in adults

Target patient group: Adult
Target professional group(s): Pharmacists
Secondary Care Doctors
Secondary Care Nurses
Adapted from:

Evidence base

Approved By

Improving Antimicrobial Prescribing Group

Document history

LHP version 2.0

Related information

Not supplied

Equity and Diversity

The Leeds Teaching Hospitals NHS Trust is committed to ensuring that the way that we provide services and the way we recruit and treat staff reflects individual needs, promotes equality and does not discriminate unfairly against any particular individual or group.