A review of bites by non-front-fanged snakes (NFFS) of Europe

Non-front-fanged snakes (NFFS) have long been overlooked by snake venom research, likely due to most of them being considered non-medically relevant for humans. The paucity of information about composition and activities of NFFS venoms and oral secretions makes it difficult to assess whether a given species can inflict medically significant bites. Here, we provide a review of the information currently available about the symptoms/signs elicited by bites from European NFFS, aiming to offer a foundation for understanding the threat they pose in terms of snakebite. Despite an overall limited amount of available data for most of the considered taxa, the genus Malpolon is notable for its capacity to cause local and systemic envenoming, including neurotoxic symptoms. Bites by other genera like, Hemorrhois, Hierophis, Natrix, Platyceps, Telescopus, and Zamenis are mainly associated with local symptoms, but the extent of their medical significance remains unclear. Our findings suggest that, although bites from European NFFS generally cause only mild effects, the potential occurrence of systemic effects from some species cannot be ruled out. Considering the above, any bite by European NFFS should receive professional medical evaluation in order to ensure patient safety and appropriate management, as well as detailed documentation facilitating construction of an accurate medical risk profile for the species.