Global prevalence of neurotoxic and hemotoxic snakebite envenomation: a systematic review and meta-analysis

Background: According to the World Health Organization, globally, there are ~5.4 million snake bites and 1.8–2.7 million cases of envenomation, with 81 410–137 880 deaths annually. Aims: To estimate using a comprehensive systematic review and meta-analysis the prevalence of neurotoxic and haemotoxic snake bite envenomation. Methods: Medline/PubMed, Scopus and Cochrane Library were searched up to January 2021 using keywords such as snake bite and snake envenomation. A bibliographic search and random search were also performed. Prospective or retrospective observational studies and randomized controlled trials were included in the review. Results: We included 271 of 9711 studies published between 1963 and 2020. The pooled prevalence of snakebite from 188 studies with a total of 207 235 participants showed the highest prevalence in North America [69.20%; 95% confidence interval (CI): 57.06–81.34%] and lowest in Africa (28.10%; 95% CI: 22.22–33.98%). There was a pooled prevalence of 24.94% (95% CI: 22.84–27.03%) of haemotoxicity, with a highest prevalence of coagulopathy (43.76%; 95% CI: 33.15–54.37%). The overall prevalence of neurotoxicity was 38.20% (95% CI: 31.88–44.53%), with a highest prevalence of ptosis (53.57%; 95% CI: 38.51–68.62%). Conclusion: There was a higher prevalence of snakebite in North America. The most prevalent haemotoxicity and neurotoxicity were coagulopathy and ptosis, respectively. The overall quality of evidence was good with a nonsignificant publication bias.