Injuries caused by the venomous catfish pintado and cachara (Pseudoplatystoma genus) in fishermen of the Pantanal region in Brazil

Abstract

INTRODUCTION: the fishing activity throughout the Upper Paraguay River Basin has huge financial and biological importance. This retrospective study investigated the occurrence of injuries caused by fish of the Pseudoplatystoma genus (spotted catfish or pintado and striped catfish or cachara) in professional fishermen of the Pantanal of Mato Grosso do Sul State. METHODS: we collected information through a questionnaire, showing that fishing is carried out by workers with low level of education, mainly adults or seniors with low financial gains. RESULTS: in Miranda town, 126 of 315 fishermen were interviewed and 38 individuals reported injuries (30.16%). In Corumbá town, 355 of 627 fishermen were interviewed, and 111 (56,61%) reported injuries. The lacerated lesions were the most common, associate with edema, erythema, radiating pain to the root of the limb, paresthesias and local necrosis. More rarely, they reported the occurrence of fever, cardiac arrhythmias and cold sweating. These manifestations may be associated with late secondary infections or envenomations caused by the toxins in the stingers of the fish. Many questionable and inappropriate treatments are used, sometimes aggravating the injuries. CONCLUSIONS: the freshwater professional fishermen need guidance on first aid measures and prevention of accidents caused by these venomous fish.

Injuries caused by fish in a community of Pantanal fishermen: detection, treatment, and prevention of envenomations and trauma

“…The diversity of fish species and large number of fishermen in the Pantanal lead to injuries being common in the region, as previously published studies show 3,4 . In addition, less economically valuable species such as the freshwater stingrays can be caught; these stingrays have one to four stingers covered by venomous mucus on the tail.…”

“…Injuries may be associated with mechanical trauma from stingers, teeth, or other traumatogenic structures, and generally occur when fishermen handle the fish when withdrawing them from hooks or nets. These traumas can also include envenomations, since some of these fish are venomous and have the ability to inoculate toxins into the victim through stingers; such fish include freshwater stingrays, spotted catfish, striped catfish, and some other catfish 3,4 . In a survey carried out in fishermen's colonies in Coxim and Corumbá counties (Mato Grosso do Sul State), all fishermen reported some kind of animal-caused injury during their work, with fish causing 78% of the injuries 3 .…”

“…Traumatic lesions such as piranha bites can cause deep ulcers and severe immediate bleeding, as well as serious subsequent bacterial infections [3][4][5][6] . In addition, recommended first aid measures, such as immersion of the affected site in hot water for 30-90 minutes, were not carried out by the fishermen in this survey.…”

“…The local temperature increase with this treatment causes vasodilation, a counterbalance to the vasoconstriction caused by the venom of spotted catfish, striped catfish, stingrays, and mandis. This adds to the partial inactivation of the toxins by the heat and greatly improves the pain level of the patients [3][4][5][6] .…”

Potentially dangerous fish of the Paraiba Estuary: Identification and envenomation mechanisms

“…The tropical climate attracts a large number of beach goers and practitioners of aquatic activities, such as commercial fishing, sport fishing, scuba diving and underwater fishing, which favor the occurrence of accidents, many of which are caused by venomous aquatic animals. However, such events are insufficiently recorded, partially to the great number of victims that do not seek medical help [3].…”