The Samar cobra, Naja samarensis Peters, 1861 is one of the World Health Organization's category I venomous snakes in the Philippines. Although N. samarensis is known to inhabit Eastern Visayas, unlike N. philippinensis in Luzon, no clinical case reports have yet been published in the international literature. No immuno-diagnostic assays have been developed for venomous snakes in the Philippines, even for research purposes. Therefore, identification of the causative snake in hospitals is challenging. In vivo assay using mice, pre-clinical tests of locally-produced antivenom raised against N. philippinensis venom, ["Purified Cobra Antivenom (PCAV)"], has shown cross neutralisation of N. samarensis venom. Here, we present five snakebite envenomation cases where causative snakes were confirmed in photos as N. samarensis by an expert local herpetologist. Patients' symptoms and signs varied, from mild to extensive local cytotoxic and systemic neurotoxic envenomation. In one case, venom had been spat into the eye. Out of five patients, two underwent surgical debridement of necrotic tissue at the bite site. One paediatric patient was intubated because of cardiopulmonary arrest. Except for the spitting cobra case, four cases were successfully treated with PCAV and supportive management. These are the first clinical case reports of confirmed N. samarensis envenomation.
Toxicon : official journal of the International Society on Toxinology
Department of Emergency Medicine, Eastern Visayas Medical Center, Tacloban, Philippines.