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

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.

Aspectos Epidemiológicos e Sociais do Escorpionismo em Município do Recôncavo Baiano, Brasil

“…O escorpionismo é uma condição negligenciada de áreas tropicais e subtropicais, associada às condições de desequilíbrio ambiental, pobreza, desinformação e acesso reduzido a antivenenos efetivos 40,41 . A vulnerabilidade de um indivíduo ou população relaciona-se diretamente com a susceptibilidade a determinado agravo, associada à menor disponibilidade de recursos na atenção de forma individual ou coletiva 42 .…”

Scorpion envenomation in Brazil: Current scenario and perspectives for containing an increasing health problem

“…Besides T . obscurus , the species Tityus metuendus , Tityus silvestri s, Tityus bastosi , Tityus apiacas , and Tityus strandi seem to be responsible for most envenomation cases in Brazilian Amazonia [ 106 , 108 ].…”

“…Nevertheless, T. obscurus venom can induce similar symptoms and lethality to mice but at higher dosage and different time frame [105]. Interestingly, T. obscurus seems to contain at least two morphologically similar but toxinologically distinct subspecies, since different neurological manifestations have been observed in envenomation attributed to T. obscurus in the western area of Para state, such as symptoms described as "electrical shock," which causes body muscular contraction [33,104,106]. Torrez and colleagues [107] reported neurological disorders and electric shock-like sensations in 97% and 89%, respectively, of patients stung by T. obscurus.…”

“…Recent scientific publications have described relevant human accidents with other scorpion species, especially in the Amazon region, which has the highest Tityus species diversity [17]. Besides T. obscurus, the species Tityus metuendus, Tityus silvestris, Tityus bastosi, Tityus apiacas, and Tityus strandi seem to be responsible for most envenomation cases in Brazilian Amazonia [106,108].…”

Case Report: Fatal Scorpion Envenomation in a Shuar Child by Tityus cisandinus from Amazonian Ecuador: A Call for Specific Antivenom Availability in the Amazon Basin

“…1 In South America, the Amazon region has the highest envenomation incidence, with an estimated rate ranging between 30 and 200 cases per 100,000 inhabitants. 6 These numbers are probably higher because large sections of Amazonia remain epidemiologically underreported, particularly in the northwestern section of the Amazon Basin, comprising Ecuador, Colombia, and Peru. 6 Tityus is the buthid scorpion genus that contains species (N 5 224 as of 2021) associated with most severe and fatal envenomation cases in lower Central America, the Caribbean, and South America, particularly in the Amazon region, where the genus reaches its highest species diversity.…”