24 July, 2012

Scorpionism in Central America - a review

Tityus pachyurus is the species responsible for most sever envenomation cases in Panama. Photo: Dr. Carlos Viquez
Scorpionism in North America and South America is pretty well documented, but there have been few reports on scorpions of medical importance in Central America. This has probably been due to the scarcity of data for the region.

Borges and co-workers have now published a very good review article summing up the current knowledge of scorpionism in Central America with a special focus on Panama. Scorpions of medical importance includes species in the genera Centruroides (12 species) Marx, 1890 and Tityus C. L. Koch, 1836 (8 species). Species in the former genera seem to have minor medical importance in Central America, while at least four species in Tityus have been implicated in deaths and severe envenomations in Panama (and possible also in Costa Rica). Species of medical importance are:

Tityus asthenes Pocock, 1893
T. cerroazul Lourenço, 1986
T. festae Borelli, 1899
T. pachyurus Pocock, 1897

Belize, El Salvador, Guatemala, Honduras and Nicaragua have no documented cases of serious scorpion envenomations (but also lack the presence of Tityus).

 Scorpionism in the Americas occurs mainly in Mexico, northern South America and southeast Brazil. This article reviews the local scorpion fauna, available health statistics, and the literature to assess scorpionism in Central America. Notwithstanding its high toxicity in Mexico, most scorpion sting cases in Guatemala, Belize, El Salvador, Nicaragua, and Costa Rica are produced by species in the genus Centruroides that are only mildly toxic to humans despite the existence of ion channel-active toxins in their venoms. Regional morbidity is low with the exception of Panama, where an incidence of 52 cases per 100,000 inhabitants was recorded for 2007, with 28 deaths from 1998 to 2006. Taxa belonging to the genus Tityus (also present in the Atlantic coast of Costa Rica) are responsible for fatalities in Panama, with Tityus pachyurus being the most important species medically. Most Tityus species inhabiting Panama are also found in northern South America from which they probably migrated upon closure of the Panamanian isthmus in the Miocene era. Incorporation of Panama as part of the northern South American endemic area of scorpionism is thereby suggested based on the incidence of these accidents and the geographical distribution of Panamanian Tityus species.

Borges A, Miranda RJ, Pascale JM. Scorpionism in central America, with special reference to the case of Panama. Journal of Venomous Animals and Toxins Including Tropical Diseases. 2012;18(2):130-43. [Free full text]

Thanks to Jacek Szubert for informing me about this paper!

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