Revisiting saw-scaled viper ( Echis carinatus) bites in the Jaffna Peninsula of Sri Lanka: distribution, epidemiology and clinical manifestations

Abstract

In Sri Lanka, the saw-scaled viper ( Echis carinatus) is distributed in the arid, dry and sandy coastal plains and in a prospective study we describe its bites in the Jaffna peninsula. Of the 304 snake bite admissions to the Jaffna Hospital in 2009, 217 (71.4%) were bitten by either venomous species or envenomed by unidentified snakes. There were 99 (45.6%) reported saw-scaled viper bites, of which 26 were confirmed cases. The length of the offending snakes ranged from 228–310 mm and bites mainly occurred in the nearby islands. The median age of the confirmed cases was 34 years (range 1.5–72 years); occupations included housewives (8, 31%), school children (4, 15%) and farmers (2, 8%). In 18 patients (69%), bites occurred in daylight and in 8 (31%) within or near the compounds. The fingers were bitten in 8 (31%) and toes/foot in 11 (42%) cases. There were 2 (8%) dry bites and 19 patients (73%) developed local swelling; one patient developed haemorrhagic blisters. In 24 patients (92%), blood incoagulability manifested between 40 and 1095 min after the bite, and three patients (12%) developed spontaneous bleeding. One patient (4%) developed mild acute renal dysfunction. The median time for correction of coagulopathy was 802 min (range 180–1669 min) with Indian polyvalent antivenom. All recovered. The saw scaled viper is responsible for most venomous bites in the Jaffna peninsula.