Effective, polyvalent, affordable antivenom needed to treat snakebite in Nepal

Nepal has one of the highest snakebite fatality rates in south Asia. A study in the country in 2001 indicated an annual incidence, in the study area, of 162 snakebite-related deaths per 100 000 population.1 Between 1987 and 2013, in other studies in Nepal, snakebite fatality rates ranging between 3% (2 deaths out of 71 envenomed people) and 58% (28 deaths out of 48 envenomed people) were reported.2 An epidemiological survey of 15 hospitals indicated that, nationwide, approximately 20 000 snakebite cases and about 1000 snakebite-related deaths were occurring each year.3 Many of the reported rates underestimate the true burden posed by venomous snakes in Nepal because data recording in Nepalese hospitals is generally poor4 and many Nepalese depend on traditional healers and or do not seek hospital treatment because they consider themselves to be too poor to pay for treatment, or think there will be no benefit.2,5 If the numbers of out-of-hospital deaths caused by snakebite are to be reduced in Nepal, there needs to be improvements in the public awareness of the benefits of snakebite treatment in hospital and in the pre-hospital care of snakebite – as seen, for example, in Sri Lanka.6 The corresponding in-hospital mortality will only be reduced by increasing the availability of safe and effective antivenoms and improving critical care for people bitten by snakes. Even though at least 70 snake species are known to exist in Nepal, most of the serious envenoming and deaths from snakebite are caused by just seven species: the kraits Bungarus caeruleus, B. walli, B. lividus and B. niger, the cobras Naja naja and N. kaouthia and the viper Daboia russelii.7,8 Although hospital data indicate that just 3% of snakebites (10 out of 349 recorded snakebites) in Nepal are caused by pit vipers,7 many people bitten are never admitted to hospitals because the resultant envenoming is usually mild and or the bitten individuals prefer to seek care from traditional healers. However, some pit viper bites can cause severe coagulopathy.9 In Nepal, antivenom for treating pit viper bites is currently unavailable, but two antivenoms, raised against pit vipers from other countries, were used successfully, in Australia, to treat a pit viper bite that occurred in Nepal.9