An epidemiological study of snake bite envenomation in Papua New Guinea

We report a study of 347 patients with snake bite envenomation in Papua New Guinea. The male: female ratio of the victims was 1.6:1 and their mean age was 24.5 years; 26% were children less than 15 years old. In all cases in which the bite site was known (334) the snake had bitten the extremities of the victim, with 71.3% of these bites being on the ankle or below. The patients came from three regions: urban Papua, rural Papua and (mostly rural) New Guinea. Snake bites occurred more frequently during the daytime in all regions, but this pattern was less obvious in New Guinea (P = 0.004), reflecting the predominance of the death adder (Acanthophis antarcticus) in New Guinea and of the taipan (Oxyuranus scutellatus canni) in Papua. Bites were commoner in the rainy season (November to April) in all groups, but this was less noticeable in rural Papua and New Guinea (P = 0.004). This may relate to seasonal activities of the rural population. The female:male ratio for patients from rural areas was higher for those 30 years of age and over than for those under 30 (P = 0.034), probably reflecting the increased gardening workload of older women. The incidence of envenomation and mortality rates after snake bite in Papua appear to have changed little over 25 years. However, increased relative numbers of taipans seem to be occurring in central Papua possibly related to the cane toad (Bufo marinus) and deforestation. We calculate the annual incidence of envenomation and the mortality rate per 100,000 to be 81.8 and 4.3, respectively, for rural central Papua, 21.8 and 2.1 for urban central Papua, and 3.0 and less than 1.0 for the Madang region of New Guinea. The importance of a standard management protocol and of improved first aid are emphasised.