Question - What is the prevalence of hematologic toxicity associated with envenomation by Agkistrodon controtrix?
Answer - The authors of the cited article state “Copperhead snakes (Agkistrodon contortrix) are considered as the least toxic of the North American pit vipers.” Their study reports on 244 cases and they found “Hematologic toxicity occurred in 14% (95% CI 10–18%) of patients. Specific indices included thrombocytopenia in 1.2% (95% CI 0.4–3.6%), hypofibrinogenemia in 0.7% (95% CI 0.0–3.8%), elevated PT in 10.0% (95% CI 6.8–14.5%), and aPTT in 3.9% (95% CI 2.1–7.2%) of patients. There was no clinically significant bleeding reported in any case.” (Brandon K. Wills, et al. Prevalence of hematologic toxicity from copperhead envenomation: an observational study, 2019 Clinical Toxicology, DOI: 10.1080/15563650.2019.1644346)