Acidentes por serpente Helicops modestus (Günther, 1861): estudo retrospectivo de 442 casos atendidos no Hospital Vital Brazil no período de 1945 a 2019

Abstract

The species Helicops modestus Günther, 1861 occurs in Southern, Southeastern and Midwestern Brazil, with one record for the Northeastern region. They have morphological adaptations to the aquatic environment of different habitats. H. modestus feeds mainly on fishes and occasionally on amphibians. Although some authors have argued that its bite causes only mild and transient local effects, as far as we know, there are no studies with a significant number of well-documented cases containing sufficient details to fully evaluate the medical risk potential of this species. We aim to describe the epidemiological and clinical aspects of the H. modestus accidents. We retrospectively analyzed 442 proven cases of H. modestus bites admitted to Hospital Vital Brazil HVB, Butantan Institute, São Paulo, Brazil, between 1945 and 2019. Only cases in which the causative animal was brought and identified were included. Of the 442 cases, only 82 had the gender of the snake recorded, and 66 80.5% were female. The length of snakes snout-vent length was measured in 116 cases and ranged from 16 to 132 cm, with a mean of 47.9 ± 19.1 cm. Of the 257 snakes, 217 84.4% were adults and 40 15.6% immature. Most bites occurred in summer n=246, 56.7% and spring n=106, 24.0%, near or in streams, rivers, ponds or pools n=147, 33.3%, in the afternoon n=184, 41.7% and evening n=170, 38.5%, and in the limbs feet 38.2%, hands 31.3%. The age of the victims ranged from 1 to 75 years old, with a median of 21 years interquartile interval = 10–32 years, and 276 62.4% patients were men. Around 89% of the patients sought medical care within 6 h after the bite. The local clinical manifestations were pain n=225, 50.9%, bleeding n=169, 38.2%, erythema n=68, 15.4%, edema n=53, 12.0%, intense pain n=12, 2.7% and paresthesias n=8, 1.8%. Only 27 6.1% patients reported systemic symptoms characterized mainly by dizziness 4.3% or tremors 1.1% and 122 patients 27.6% showed no evidence of envenoming. The whole blood clotting test was performed in 92 patients on admission and all of them had coagulable blood. Supportive treatment was offered to 51.8% of the patients, mainly antiseptic n=179, 40.5%, antihistamine n=73, 16.5%, and analgesic n=18, 4.1%. Fourteen patients 3.2% were treated with antivenom before their admission to HVB. No sequels or relevant complications were observed in patients, and the prognostic was benign. Therefore, although H. modestus accidents can cause mild local symptomatology, health professionals must know how to make the correct diagnosis to avoid unnecessary use of antivenom.