Scorpion envenomations in southeastern Ecuador

Juan Roman and co-workers have studied scorpion envenomations in rural locations in the Amazonian province of Morona Santiago, southeastern Ecuador. The severity of scorpion stings in this region is reported and the conclusion is that scorpions are a public health problem, especially for young children.

A phylogenetic analysis of the scorpions involved in serious cases were conducted and revealed that these were caused by a species in the Tityus obscurus group (Buthidae). This group contains species responsible for severe envenomations in other areas of the Amazonian Basin. The Ecuadorian species involved is unknown, and will be described as a new species in a future publication.

Scorpion envenoming by species in the genus Tityus is hereby reported from rural locations in the Amazonian province of Morona Santiago, southeastern Ecuador. Twenty envenoming cases (18 patients under 15 years of age) including one death (a 4-year-old male) were recorded at the Macas General Hospital, Morona Santiago, between January 2015 and December 2016 from the counties of Taisha (n =17), Huamboyo (n= 1), Palora (n =1), and Logroño (n =1). An additional fatality from 2014 (a 3-year-old female from Nayantza, Taisha county) is also reported. Leukocytosis and low serum potassium levels were detected in most patients. We observed a significant negative correlation between leukocytosis and hypokalemia. Scorpions involved in three accidents from Macuma, Taisha County, were identified as genetically related to Tityus obscurus from the Brazilian Amazonian region based on comparison of mitochondrial DNA sequences encoding cytochrome oxidase subunit I. These cases, along with previously reported envenoming from northern Manabí, reinforce the notion that scorpionism is a health hazard for children in Ecuador and emphasizes the need to supply effective antivenoms against local species, which are not currently available. The genetic affinity of the Ecuadorian specimens with T. obscurus may underlay toxinological, clinical, and venom antigenic relationships among Amazonian scorpions that deserves further exploration for designing therapeutic strategies to treat scorpionism in the region.

Roman JP, Garcia F, Medina D, Vasquez M, Garcia J, Graham MR, et al. Scorpion envenoming in Morona Santiago, Amazonian Ecuador: Molecular phylogenetics confirms involvement of the Tityus obscurus group. Acta Trop. 2017;178:1-9. [Subscription required for full text]

Thanks to Adolfo Borges and Matthew Graham for both sending me their article!