Confronting the neglected problem of snake bite envenoming: the need for a global partnership

Abstract

Envenoming resulting from snake bites is an important public health hazard in many regions of the world, yet public health authorities have given little attention to the problem.

Figure 1. Snakes Causing High Incidence of Envenomings in Africa, Asia, and Latin America

(A) Echis ocellatus (saw-scaled viper, family Viperidae, from Nigeria), (B) Naja naja (cobra, family Elapidae, from Sri Lanka), and (C) B. asper (terciopelo or equis, family Viperidae, from Costa Rica) are responsible for many snake bite envenomings in sub-Saharan Africa, Asia, and Central America, respectively. Envenomings by E. ocellatus and B. asper, as well as by related viperid species, induce prominent local tissue damage that often results in permanent sequelae and disability, and systemic alterations associated with haemorrhage, coagulopathy, cardiovascular shock, and renal failure. Envenomings by N. naja and other Asiatic cobras induce systemic neurotoxic effects and local necrosis. (Image: D. A. Warrell [A and B]; Mahmood Sasa [C])

Figure 2. Extensive Tissue Necrosis of the Lower Limb in an 11-Year-Old Boy Who Had Been Bitten Two Weeks Earlier by a B. asper in Ecuador

Only antibiotic treatment had been given, so tissue damage was extensive, requiring above-knee amputation. Such pathological alterations are caused by the direct action of locally acting toxins in the venom (mostly metalloproteinases and phospholipases A ₂), together with an indirect effect promoted by local inflammatory events and ischemia secondary to venom-induced vascular damage and increased intracompartmental pressure. (Image: D. A. Warrell)

Figure 3. Scientific, Technological, and Political Tasks Required to Improve the Prevention and Treatment of Snake Bite Envenoming

There is an urgent need to gain a deeper knowledge of the epidemiology and clinical manifestations of snake bite envenoming around the globe, and to promote research and public health policies aimed at improving the treatment and prevention of these envenomings, particularly regarding antivenom production and distribution, as well as training of medical staff. The fulfilment of these tasks requires a concerted effort involving many actors at both national and international levels. PLA ₂s, phospholipases A ₂.