Amazonian scorpions and scorpionism: integrating toxinological, clinical, and phylogenetic data to combat a human health crisis in the world's most diverse rainfores.

Adolfo Borges,Pedro P O Pardal,Denise M Cândido,Matthew R Graham

doi:10.1590/1678-9199-jvatitd-2021-0028

Abstract

Venom from Amazonian scorpions of the genus Tityus contains components capable of eliciting a distinct clinical, mostly neurological, syndrome. This contrasts with the mainly autonomic manifestations produced after envenomation by congeneric southern and northern South American species. Herein, we summarize Pan-Amazonian scorpionism by synthesizing available toxinological, clinical, and molecular data gathered from all affected areas in Amazonia, including Brazil, Ecuador, Colombia, Peru, Venezuela, and French Guiana. We searched multiple databases, as well as our own records, for reports of scorpion envenomations in Amazonia by confirmed Tityus spp., and compared the clinical manifestations. To help uncover clinical and venom relationships among problematic species, we explored phylogenetic relationships with a rate-calibrated analysis of mitochondrial COI data from available species. The possible existence of diversity gradients for venom toxic and immunogenic components despite the predicted strong phylogenetic association among species is underscored by discussed clinical and toxinological findings. A multicentric effort, involving all nations affected by this neglected disease, is urgently needed to offer alternatives for treating and understanding this pathology, including the preparation of neutralizing antibodies with a broad range of efficacy.

Highlights

Scorpionism, or the medical consequence of scorpion stings in humans, is a neglected health problem in tropical and subtropical areas associated with poverty and the lack of access to effective antivenoms
Neurological manifestations, including tonic-clonic convulsions, have been reported after scorpion stings in areas inhabited by T. perijanensis [38], a species inhabiting the Colombia/ Venezuela border, which has been shown to produce sodium channel-active toxins structurally related to toxins from T. obscurus and T. metuendus [33]
Muscle fasciculations were recorded after T. breweri envenomation in Amazonian Venezuela, and by a Tityus spp. in Huila, southern Colombia (Imeri area of endemism), which is a manifestation not usually observed after stings by Tityus spp. in those countries, and is reminiscent of similar effects in the case of T. obscurus [15, 16] (Table 2)

Summary

Introduction

Scorpionism, or the medical consequence of scorpion stings in humans, is a neglected health problem in tropical and subtropical areas associated with poverty and the lack of access to effective antivenoms. [33], indicate that species from Lower Central America, Colombia, and the Amazonian regions of Brazil, Ecuador, Peru, and French Guiana, might share enough molecular and toxinological similarities to justify preparation of a scorpion antivenom that should neutralize common venom toxic components.

Results

Conclusion