Envenomation by the Scorpion Tityus breweri in the Guayana Shield, Venezuela: Report of a Case, Efficacy and Reactivity of Antivenom, and Proposal for a Toxinological Partitioning of the Venezuelan Scorpion Fauna

• Published in: Wilderness & environmental medicine Vol. 21; no. 4; pp. 282 - 290
• Main Authors: Borges, Adolfo, Rojas-Runjaic, Fernando J.M., Diez, Nardy, Faks, José G., Op den Camp, Huub J.M., De Sousa, Leonardo
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Elsevier Inc 01-12-2010; SAGE Publications; Elsevier Limited
• Subjects: Adult; Animals; Antivenins - therapeutic use; Emergency; Guayana; Humans; Hydrocortisone - therapeutic use; Male; Scorpion Stings - diagnosis; Scorpion Stings - immunology; Scorpion Stings - therapy; scorpion toxin; scorpion venom; Scorpion Venoms - antagonists & inhibitors; Scorpion Venoms - toxicity; scorpionism; Scorpions - classification; Scorpions - pathogenicity; Tityus; Tityus breweri; Venezuela; Young Adult; Venezuela; Venezuela; scorpionism; Tityus breweri; Tityus; scorpion toxin; Guayana; scorpion venom
• ISSN: 1080-6032; 1545-1534
• DOI: 10.1016/j.wem.2010.06.008

Objectives Scorpion envenomation is a common public health problem in Venezuela. We report an envenoming case by Tityus breweri , endemic to the Guayana Shield, southeast Venezuela, and the outcome of its treatment with antivenom anti– Tityus discrepans . Toxin composition and antigenic reactivity of T breweri venom were also explored. T breweri distribution range was re-evaluated. Methods Clinical signs and symptoms in an adult male were recorded after envenoming and treatment with antivenom. Toxin composition and antigenicity of T breweri venom were investigated by polyacrylamide gel electrophoresis, immunoblotting, and mass spectrometry. T breweri distribution range was reassessed by mapping new records of the species. Results The moderately severe case (a 21-year-old man) presented autonomic manifestations, including cardiopulmonary and gastrointestinal effects. Full recovery was achieved after anti– T discrepans antivenom administration. T breweri venom contains toxins in the 6–8 kd range that affect voltage-sensitive sodium channels. Based on new records, T breweri distribution area reaches 12 155 km. Inclusion of southeast Venezuela as an endemic area of scorpionism prompted the examination of clinical, immunological, and phylogenetic evidence for suggesting a partitioning of the Venezuelan Tityus fauna into toxinological provinces. Conclusions The severity of the case reinforces categorization of the Guayana Shield region as a macroendemic area of scorpionism in Venezuela and allows classification of T breweri as a species of medical importance, with toxins immunologically related to central-eastern Venezuelan Tityus . Partitioning of the territory incorporating multiple criteria may help health authorities establish and implement preventive and therapeutic measures for scorpion envenoming in this region.