Postmortem histopathology and detection of venom by ELISA following suicide by cobra (Naja kaouthia) envenomation

Purpose: Forensic proof of venomous snakebite is challenging, particularly when the snake species involved is not endemic to the region in which the event occurred. This case report describes postmortem histopathological findings and venom detection following suicide by monocled cobra (Naja kaouthia) envenomation, at a location (Texas, USA) where that animal is not normally encountered. Methods: External, internal and histopathological examination was performed according to the standard of the local office of the medical examiner. Tissue homogenate and blood were assayed with a Naja-specific enzyme-linked immunosorbent assay (ELISA), using locally obtained coral snake (Micrurus) venom as negative control. Results: External evidence of puncture marks, edema and erythema were associated with local evidence of microscopic necrosis, acute inflammation, vascular congestion and lymphadenitis. Cobra venom was present in cardiac serum and at higher concentrations in serum, soft tissue and lymph nodes near the puncture sites. Conclusion: In the absence of commercial kits for venom detection, confirmation of snake envenomation postmortem can be achieved by correlation of specific ELISA with local findings. Exclusion of related local snake venom is necessary to confirm the specificity of the assay.