Clinical picture of envenoming with the Meadow Viper (Vipera (Acridophaga) ursinii)

Abstract

Objective. The vipers in the Vipera (Acridophaga) ursinii complex are small-sized insectivorous snakes found in parts of central and southern Europe. Subspecies include Vipera ursinii ursinii, Vipera ursinii moldavica, Vipera ursinii macrops, Vipera ursinii rakosiensis, and Vipera ursinii graeca and are commonly known as the meadow vipers. These are the least known European Vipera from a clinical point of view. Methods. We identified cases of V. ursinii envenomations through three methods, including literature search in PubMed, ISI web of Knowldge, JSTOR, Biological Abstracts, Zoological Record, using the various combination of the following terms: snakebite, envenoming, bite, venom, ursinii, meadow viper, steppe viper (in English, French, Italian, Hungarian, Croatian, Serbian, Romanian), review of paper-based medical case records of hospitals in Hungary (four) and Romania (one) covering the 1970–July 2010 period, and personal communications of professional and amateur herpetologists studying V. ursinii and snake-handlers bitten by these snakes. Results. We identified 64 cases from subspecies: V. u. ursinii (14), V. u. moldavica (8), V. u. macrops (5), and V. u. rakosiensis (37). Forty-five bites were collected from the literature, 5 from hospitals, 10 cases were communicated by seven herpetologists and four cases by two snake keepers. Bites were mostly asymptomatic. Forty-five envenomings (70%) resulted in mild and moderate local symptoms, involving pain with low-intensity, pruritus, numbness, swelling with or without erythema and/or local hematoma. Bullae (n = 3, 5%), mild superficial necrosis (n = 4, 6%), cellulitis (n = 1, 2%), and moderately extended edema (n = 8, 13%) of the bitten extremity rarely develop. Massive limb edema was recorded in eight (13%) cases. The most common systemic symptoms were dizziness caused by transient hypotension and tachycardia. Gastrointestinal disorders (i.e. nausea, vomiting) were rare (n = 2, 3%) compared to other Vipera, and probably triggered only by anxiety. Symptomatic and supportive therapy was applied in the relatively severe envenomings and antivenom therapy in six cases. Complete recovery ranged from 12 h to 2 weeks. Moderate and severe envenomings required significantly longer recovery. Application of first aid was associated with significantly longer recovery times. Neither the age (i.e. juvenile or adult) of the culprit specimen, nor the anatomical location of the bite determined the severity of symptoms. Conclusion. Professional and amateur herpetologists, and snake keepers are mainly at risk. Most V. ursinii bites do not require first aid or medical intervention, since only local symptoms develop and resolve spontaneously. The rare hospitalized cases require symptomatic and supportive treatment only. Antivenom therapy is not indicated.

Keywords:

• Snakebite
• Envenoming
• Limited swelling

Acknowledgments

We thank the hospitals, researchers and snake-keepers, who provided data on their accidents, and Dr. Oscar Arribas (Barcelona, Spain), Tamás Péchy (Budapest, Hungary), Bálint Halpern (Budapest, Hungary), AB, and Nikola Rahme (Budapest, Hungary) for the photographs. Special thanks to Alexander Westerström (Stockholm, Sweden) for providing photographs and data on V. u. macrops envenomings and for translating Swedish materials. Bálint Halpern (Budapest, Hungary) is acknowledged for drawing the map, and Tamás Tóth (Budapest, Hungary) for providing certain historical references. Prof. Dr. Deitrich Mebs (University of Frankfurt, Germany) and Prof. Dr. David A. Warrell (University of Oxford, UK) are acknowledged for their useful comments and critics.