Animal or Human Bites in Adults - Prevention of Infection

Publication: 01/07/2009

Next review: 07/02/2025

Clinical Guideline

CURRENT

ID: 1752

Approved By: Improving Antimicrobial Prescribing Group

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

Diagnostics
Management
Prophylaxis or Treatment
Prevention of transmission of associated infections
Empirical Treatment
Review by 72

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.

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).

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

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).

Empirical treatment

Empirical options following an animal or human bite
Duration: Prophylaxis = 3 days Treatment = 5 days³
1st line	Co-amoxiclav 625mg PO 8-hourly
Alternative 1st line if penicillin allergy or co-amoxiclav unsuitable	Doxycycline PO 200mg on day one then 100mg daily (increase to 100mg twice daily in severe infection⁴) AND Metronidazole PO 400mg 8-hourly
Alternative 1st line in pregnancy if penicillin allergy or co-amoxiclav unsuitable⁵	Azithromycin PO 500mg daily AND 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 IV 750mg 8-hourly⁶ AND Metronidazole IV 500mg 8-hourly
	Oral switch: Non-pregnant patients: Doxycycline PO 100mg daily (increase to 100mg twice daily in severe infection⁴) AND Metronidazole PO 400mg 8-hourly Pregnant patients: Azithromycin PO 500mg daily AND Metronidazole PO 400mg 8-hourly

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

High risk areas include the hands, feet, face, genitals, skin overlying cartilaginous structures or an area of poor circulation.
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).
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
Severe infection defined as: evidence of spreading cellulitis, tissue damage or child systematically unwell.
Choice for pregnant women taken from draft NICE guidance that formed final version of NG184 (see evidence)
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

NICE: Human and animal bites: antimicrobial prescribing. NICE guideline [NG184] Published date: 04 November 2020 https://www.nice.org.uk/guidance/ng184/resources/visual-summary-pdf-8897023117
NICE: CKS Bites - human and animals. Last revised: October 2020 https://cks.nice.org.uk/topics/bites-human-animal/

Approved By

Improving Antimicrobial Prescribing Group

Document history

LHP version 2.0

Related information

Not supplied

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