A case of exotic envenomation by Naja kaouthia in Mexico

Abstract

In Mexico, an average of 3,893 venomous snakebites is registered annually. Since not all bites are informed, that figure is likely an underestimation. Most bites involve snakes native to Mexico, but reports do not distinguish among the species involved, so the percentage of bites caused by exotic (non-native) snakes is unknown. However, numerous exotic species of venomous snakes are kept in the country, both legally and illegally. Commonly, owners of these snakes do not acquire appropriate antivenoms, leaving themselves vulnerable to severe envenomation. In this article we present the clinical case of a 25-year-old man bitten on the right index finger by a monocled cobra (Naja kaouthia). He developed severe neurotoxicity 15 minutes after the bite and required ventilator support for 16 hours. He recovered after the intravenous administration of eight vials of antivenom specific to N. kaouthia. He had necrosis at the site of the bite, which covered two thirds of the finger but resolved satisfactorily without surgical intervention. Quantitative ELISA assays on seven serum samples confirmed the envenomation and illustrated a secondary rise and fall in systemic venom levels during antivenom treatment.