Wound infection secondary to snakebite

Abstract

Background. Snakebites can produce severe local and systemic septic complications as well as being associated with significant overall morbidity and even mortality. Objective. A prospective audit was undertaken to determine the bacterial causation of wound infection secondary to snakebite, and attempt to quantify the burden of disease. Methods. The audit was undertaken at Ngwelezane Hospital, which provides both regional and tertiary services for north-eastern KwaZuluNatal Province, South Africa, over a 4-month period. Records of patients who required surgical debridement for extensive skin and softtissue necrosis were analysed. At the time of debridement, tissue samples of necrotic or infected tissue were sent for bacteriological analysis as standard of care. Microbiology results were analysed. Results. A total of 164 patients were admitted to hospital for management of snakebite, of whom 57 required surgical debridement and 42 were included in the final microbiological analysis. Children were found to be the most frequent victims of snakebite; 57.8% of patients in this study were aged ≤10 years and 73.7% ≤15 years. Culture showed a single organism in 32/42 cases, two organisms in 8 and no growth in 2. Eight different types of organisms were cultured, five of them more than once. Thirty-five specimens (83.3%) grew Gram-negative Enterobacteriaceae, the most frequent being Morganella morganii and Proteus species. Thirteen specimens (31.0%) grew Enterococcus faecalis. Gram-negative Enterobacteriaceae showed 31.4% sensitivity to ampicillin, 40.0% sensitivity to amoxicillin plus clavulanic acid, 34.3% sensitivity to cefuroxime, 97.1% sensitivity to ceftriaxone, and 100% sensitivity to ciprofloxacin, gentamicin and amikacin. E. faecalis was 92.3% sensitive to amoxicillin, 92.3% sensitive to amoxicillin plus clavulanic acid, 100% sensitive to ciprofloxacin, 92.3% resistant to erythromycin and 100% resistant to ceftriaxone. Conclusion. Children are particularly vulnerable to snakebite, and the consequences can be devastating. While the majority of patients in this study were shown to have secondary bacterial infection, debridement and subsequent wound management is considered the mainstay of treatment. Common organisms are Enterobacteriaceae and enterococci. There appears to be a role for antibiotics in the management of these patients. A good antibiotic policy is strongly advocated.

Microbial adaptation to venom is common in snakes and spiders

“…From a clinical perspective, identification of E. faecalis as the most prevalent culturable microbe 20 across our European N. nigricollis venom samples strikingly reflects three independent clinical reports across Africa and Asia that this non-sporulating microbe is the most common Gram positive infection cultured from infected envenomation wounds (Mao et al 2016;Lam et al 21 2011;Wagener et al 2017). Further epidemiological data from countries with high envenomation incidence (Mao et al 2016;Lam et al 2011;Wagener et al 2017;Johnston et al 2017;Monteiro et al 2002) challenge the consensus view in developed nations that venom is sterile, opportunistic primary infection upon envenomation is uncommon, and that venom wound infection is a consequence of poor hygiene or poor debridement practice (Talan et al 1991;5 Powers 2005). Accordingly, in an experimental rabbit model of dermonecrosis (Monteiro et al 2002) caused by Loxosceles intermedia (recluse spider) venom, Clostridium perfringens recovered from the spider fang and venom enhanced disease symptoms.…”

“…Yet over three quarters of snake bite victims may develop mono-or polymicrobial envenomation wound infections, characterized by Bacteroides, 15 Morganella, Proteus, and Enterococcus (Wagener et al 2017;Mao et al 2016) -bacterial taxa commonly found in the gut. Indeed, Enterococcus faecalis and Morganella morganii have been independently reported as the most common Gram positive and Gram negative infections across several countries (Mao et al 2016;Lam et al 2011;Wagener et al 2017). Historically associated with the oral snake microbiome (Jorge et al), these bacteria are thought to originate from prey 20 faeces (Garg et al 2009) persisting in the snake oral cavity (Lam et al 2011) with a diversity similar to that of the snake gut (Iqbal et al 2014).…”

Surgical Infections in Low- and Middle-Income Countries: A Global Assessment of the Burden and Management Needs

“…Approximately 5 million snake bites are estimated to occur annually, the majority occurring in Africa and southeast Asia [103]. Infections after a snakebite have been reported to affect 9%-35% of victims [106,107].…”

Do Antibiotics Potentiate Proteases in Hemotoxic Snake Venoms?

“…The administration of antibiotics is recommended by the World Health Organization (WHO) for snakebite victims, with the purpose of preventing sepsis or necrosis, or avoiding secondary infection when the bite wound has obviously been tampered with [1]. Antibiotics are also sometimes administered prophylactically to snakebite victims, even under conditions different from those recommended by the WHO [2][3][4]. This study aims at investigating, for the first time, the effect of antibiotics on snake venom toxins.…”