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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. 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. 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. 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.

Context: Historically, administration and dosing of antivenom (AV) have been guided primarily by physician judgment because of incomplete understanding of the envenomation process. As demonstrated ...

The venom of the Eastern coral snake Micrurus fulvius can cause respiratory paralysis in the bitten patient, which is attributable to β-neurotoxins (β-NTx). The aim of this work was to study the biodistribution and lymphatic tracking by molecular imaging of the main β-NTx of M. fulvius venom. β-NTx was bioconjugated with the chelator diethylenetriaminepenta-acetic acid (DTPA) and radiolabeled with the radionuclide Gallium-67. Radiolabeling efficiency was 60%-78%; radiochemical purity ≥92%; and stability at 48 h ≥ 85%. The median lethal dose (LD50) and PLA₂ activity of bioconjugated β-NTx decreased 3 and 2.5 times, respectively, in comparison with native β-NTx. The immune recognition by polyclonal antibodies decreased 10 times. Biodistribution of β-NTx-DTPA-(67)Ga in rats showed increased uptake in popliteal, lumbar nodes and kidneys that was not observed with (67)Ga-free. Accumulation in organs at 24 h was less than 1%, except for kidneys, where the average was 3.7%. The inoculation site works as a depot, since 10% of the initial dose of β-NTx-DTPA-(67)Ga remains there for up to 48 h. This work clearly demonstrates the lymphatic system participation in the biodistribution of β-NTx-DTPA-(67)Ga. Our approach could be applied to analyze the role of the lymphatic system in snakebite for a better understanding of envenoming.