The purpose of this chapter is to examine the evidence of a relationship between climatic changes and snake species distribution in relation with the snakebites risk increment against human populations. The global climatic change is a key factor leading to snake species behavioral changes mainly because of the rise of temperature. The variety of venomous snakes and their related potency toward human being have been well documented. Thus, this may serve as a basic knowledge for any preventive act in the face of snake toxins and their caused physiopathological and clinical effects. In addition, several studies have shown that global warming have caused a change in snake habitat and distribution, thus leading to an increase of overlapped human and snake populations living territories which raise up the risk of envenomation. Globally, more than 20,000 deaths occur every year with a high tendency to increase. Thus, consideration of human risk of envenomation may be fundamental to the effective intervention in epidemiological and clinical scales.
TopIntroduction
Numerous animal species have the potential to bite and cause envenoming in humans, but snakes have a considerable epidemiological importance. Worldwide, up to five million people are bitten by snakes every year, within which venomous snakes cause considerable morbidity and mortality (World Health Organization, WHO 2018). However, snakebite received little attention from national and international health authorities (Gutiérrez et al., 2006; Williams et al., 2010), and is now categorized as a neglected tropical disease (WHO 2018; White, 2018). At least 421,000 envenoming’s and 20,000 deaths occur each year due to snakebite globally, but these numbers may be as high as1.8millionenvenomings and 94,000 deaths (Kasturiratne et al., 2008). In fact, morbidity and mortality resulting from snake bites remain unclear and often go unrecorded in many undeveloped regions of the world.
In practical terms, the true global incidence of current snakebite risk predictions and its associated mortality are difficult to estimate (Kasturiratne et al., 2008). This is due to the fact that information on epidemiological indicators, incidence, mortality, and morbidity of snakebites is not comprehensive both within particular countries and globally for several reasons. For example, few reliable incidence data are available from the rural tropics where snakebites are higher but reliable data are mostly limited to a few developed countries where bites are rare (WHO, 2018). Thus, information on the total number of envenomed individuals cannot be obtained, and actually tracing such people within health institutions is practically impossible. Also, the only data available is on patients dealt with by toxicology centers or hospitalized at particular institutions (Chippaux, 2008).
Snakebites incidence depends on several factors such as climate, ecological parameters, distribution of venomous snakes, human population density and economic activities (Chippaux, 2008). However, treatment of snakebite envenoming is depending on the species responsible for the bite, and the only approved and accepted treatment is the use of antivenoms. Hence, antivenoms should be carefully distributed based on the distribution of the problem (Gutiérrez, 2012; Hansson et al., 2013). In this way, knowledge regarding the distributional patterns (and potential changes) of venomous snakes becomes essential for rapid identification of dangerous species, and so the suitable treatment of snakebite accidents. Therefore, increasing the knowledge of distributional ranges, activities, behavior and suitable habitats of venomous snakes is necessary in treating snakebite envenoming (Chippaux, 2008; Valenta, 2010). In addition, it would be important to evaluate if climate change can produce changes in snake’s species’ suitable climate spaces, which in turn could be important when addressing the problem (Nori et al., 2014; Yañez-Arenas et al., 2016). In this work the authors try to identify effects of climate change on venomous snake distribution and snakebites epidemiology.