The role of antimicrobial prophylaxis in the management of snakebite: a systematic review

Snakebite, a neglected tropical disease disproportionately affecting lower-income countries, is a significant cause of morbidity and mortality worldwide. Local toxicity and necrosis may result in secondary bacterial infection of bite sites. Despite most guidelines not recommending prophylactic antimicrobials, their use is common in practise. This review aims to systematically assess literature around the use of prophylactic use of antimicrobials in snakebite. We also aim to assess the incidence of secondary infections, types of antimicrobials used, and the aetiology of infections arising from snakebite.

Systematic database searches for studies assessing prophylactic antimicrobial use undertaken. Data was assessed by two reviewers and extracted using a standardised proforma. Included studies were assessed for risk of bias and data extracted narratively. The protocol was prospectively registered on PROSPERO database (CRD42023430752).

492 studies were screened. Four met the inclusion criteria, totalling 696 patients across three countries. No study found a statistically significant benefit for the use of antibiotic prophylaxis, with no effect on the number or severity of adverse incidents. There were 114 adverse incidences related to secondary infection, with nineteen positive cultures.

This review finds little evidence pertaining to the use of antimicrobial prophylaxis. Studies were highly heterogenous with incomplete reporting of standardised processes. Bacteria isolated supports existing observational data implicating bacteria found in snake oral flora (e.g. M. morganii and Enterococcus spp). This is an important consideration when deciding empirical antimicrobial regimens for suspected superadded infection. International consensus is required to define infection following snakebite and further high-quality research is required to draw definitive conclusions regarding antimicrobial prophylaxis.