Clinical aspects of envenomation caused by Tityus obscurus (Gervais, 1843) in two distinct regions of Pará state, Brazilian Amazon basin: a prospective case series

Abstract

BackgroundScorpion envenomations are a major public health problem in Brazil, whose most dangerous cases are attributable to the genus Tityus. This study was designed to compare the clinical and demographic features of envenomations by Tityus obscurus in two areas of the state of Pará located in the Amazon basin.Were compared demographic findings, local and systemic signs and symptoms of human envenomations caused by T. obscurus that occurred in western and eastern areas of the state.ResultsForty-eight patients with confirmed envenomation by T. obscurus were evaluated from January 2008 to July 2011. Most of them came from the eastern region, where male and female patients were present in similar numbers, while males predominated in the west. Median age groups were also similar in both areas. Most scorpion stings took place during the day and occurred significantly more frequently on the upper limbs. The time between the sting and admission to the health center was less than three hours in both areas. Most eastern patients had local manifestations while in the west, systemic manifestations predominated. Local symptoms were similar in both areas, but systemic signs and symptoms were more common in the west. Symptoms frequently observed at the sting site were local and radiating pain, paresthesia, edema, erythema, sweating, piloerection and burning. The systemic manifestations were significantly higher in patients from the west. Futhermore, neurological symptoms such as general paresthesia, ataxia, dysarthria, myoclonus, dysmetria, and electric shock-like sensations throughout the body were reported only by patients from the west.ConclusionThe present study shows that two regions of Para state differ in the clinical manifestations and severity of confirmed envenomation by T. obscurus which suggests a toxicity variation resulting from the diversity of T. obscurus venom in different areas of the Brazilian Amazon basin, and that T. serrulatus antivenom can be successfully used against T. obscurus.

Clinical update on scorpion envenoming

“…Majority of the species of the Buthidae family induce similar reactions, except for Tityus obscurus in Brazil (18) (19) (20) , Centruroides (21) , and Parabuthus (22) , which also induce neurological manifestations. Signs and symptoms reported in envenoming caused by T. obscurus in some regions of Pará (Santarém) involve myoclonus (a sensation of an electric shock throughout the body), dysmetria, dysarthria, ataxia, paresthesias and hyperrefl exia, compatible with acute cerebellar syndrome with abnormal muscle movements, in addition to rhabdomyolysis and acute renal failure (19) (20) .…”

Accidents With Poisonous Animals in Brazil by Age and Sex

“…11 Accidents with scorpions show little difference between men and women with a lethality of 0.2%. Children under 10 years are the most vulnerable group.…”

Estudo clínico-epidemiológico, laboratorial e de vulnerabilidade dos acidentes escorpiônicos atendidos no Hospital Municipal de Santarém - Pará

“…Later, Pardal et al, 2013 reported more six envenomings in Santar em, all caused by T. obscurus, with similar manifestations. Our study confirms these previous publications that the singular clinical pictures observed in Santar em region are completely different and are compatible with an acute cerebellar dysfunction with abnormal muscular movements, which is not a characteristic of any other scorpion envenoming in the world (Amaral et al, 1991;Amaral et al, 1994;Brasil, 1998;Cupo et., 2009).…”

“…It is necessary to know the extent of the area in which these manifestations are described, as these are not observed in envenoming caused by this species in Bel em (Pardal et al, 2013). It is possible that T. obscurus is a complex that containing multiple species.…”

“…It is possible that T. obscurus is a complex that containing multiple species. Probably there must be some geographical barrier (e.g., Amazon River) that delimits the area of distribution of the T. obscurus that express these toxins active on the cerebellum (Pardal et al, 2013;Lourenço and Leguim, 2008).…”