Antibiotics in cat bites
Date First Published:
July 5, 2005
Last Updated:
October 14, 2008
Report by:
Tanzeem Iqbal, Medical Student (Manchester Royal Infirmary A & E Department)
Search checked by:
Dr Bernard Foex, Manchester Royal Infirmary A & E Department
Three-Part Question:
In [patients with cat bite wounds] do [prophylactic antibiotics] reduce [the incidence of wound infection]?
Clinical Scenario:
A 29 year old man presents to the Emergency Department with a cat bite wound on left his arm. He says he was bitten some 6 hours prior to attendance. The wound is cleaned and it is noted that there are no signs of infection. You wonder whether prophylactic antibiotics are required to reduce the risk of wound infection.
Search Strategy:
Ovid MEDLINE(R) 1950 to June Week 4 2008 and EMBASE 1980 to 2008 Week 27 using multifile searching
The Cochrane Library Issue 2 2008
The Cochrane Library Issue 2 2008
Search Details:
cat bite.mp. AND (wound infection.mp. or exp Wound Infection/ OR exp INFECTION/ or infection.mp.) AND (antibiotic$.mp. or exp Anti-Bacterial Agents/) LIMIT to human AND English language.
Cochrane: (cat bites):ti,ab,kw 7 records none unique
Cochrane: (cat bites):ti,ab,kw 7 records none unique
Outcome:
Medline - 25 papers found. Embase – 46 papers found. 3 of these papers were relevant. These are summarised in the table below:
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Evaluation of prophylactic oxacillin in cat bite wounds. Elenbaas R.M, McNabney W.K, Robinson W.A, 1984, USA | 12 Adult patients presenting with uninfected full-thickness wounds within 24 hrs of injury. Placebo vs oxacillin |
Prospective, double blind, placebo-controlled study | Infection Rate | 67% vs 0% (P =0.045) | This was a small study group. |
| Cat bite wounds: Risk factors for infection, Daniel J Dire, 1991, USA | 186 patients with 216 cat bite wounds / scratches over 2 years. Initially non infected bite wounds. Placebo vs antibiotic |
Prospective survey | Infection rate: Puncture wounds | Infection rate:18% vs 3% (p=0.085) | The study focused on wound type and depth, as risk factors of wound infection. Did not specify antibiotic administered, I.V antibiotics were not included in the study. |
| Infection rate: full thickness wounds | Infection rate:17% vs 3% (p=0.268) | ||||
| Infection rate: lower extremity wounds | Infection rate: 33% vs 0% (p=0.071) | ||||
| Cat bites of the hand: Mitnovetski S & Kimble F, 2004, Australia | 41 patients with cat bites of the hand seen over 3 years Combination of i.v Benzylpenicillin and Flucloxacillin effective in conjunction with surgical treatment |
Observational | Infection rate with and without antibiotics | 2% vs 28%. | Small group of patients. Not all patients were adults. Accuracy of data checked by questionnaire of which response rate was 46%. 12 % did not receive antibiotic treatment. More females than males. |
Author Commentary:
The studies found are all small and have significant methodological flaws. This area requires further appropriately designed RCTs
Bottom Line:
Antibiotic prophylaxis should be given to all cat bite wounds that are deeper than superficial.
References:
- Elenbaas R.M, McNabney W.K, Robinson W.A,. Evaluation of prophylactic oxacillin in cat bite wounds.
- Daniel J Dire,. Cat bite wounds: Risk factors for infection,
- Mitnovetski S & Kimble F,. Cat bites of the hand: