CLINICAL AND EPIDEMIOLOGIC ASPECTS OF THE URUTU LANCE-HEADED VIPER (BOTHROPS ALTERNATUS) BITE IN A BRAZILIAN HOSPITAL

Data on 32 cases of Bothrops alternatus (the 'urutu' lance-headed vipe r) bite admitted to a Brazilian teaching hospital from 1985 to 1992 we re retrospectivelly surveyed. The majority of the bites occurred withi n the household area, i. e. in the house or its environs (56.3 %), in the 15-49 years age group (74.2 %), and in the lower limbs (84.3 %). T he male to female ratio was 1 to 1. 59.4 % of the patients were given the antivenom within two hours of the bite. Bites in the household are a were commonest in old ladies, whereas all the cases associated with leisure activities, and the majority of the bites associated with labo ur in the field occurred in men. All patients had local pain and oedem a; prolonged clothing time was present in 96.9 % of the cases, haemorr hage in 40.6 %, blisters in 21.9 % and necrosis in 9.4 %. A tourniquet was used by 43.8 % of the patients. A median of 4 ampoules of antiven om were administered. There was no death in this series. There was no significant trend between increasing age and necrosis, nor between tim e interval between bite and antivenom administration and occurrence of blisters or necrosis. Presence of blister(s) was associated with necr osis (p = 0.007), but use of a tourniquet, altered clotting time or pr esence of haemorrhage were not. These findings, compared with those of case series of bites of other species of Bothrops, and contrary to th e popular belief, indicate that B. alternatus bite is not always sever e, and has even a lower rate of complications.