Epidemiology, ecology and human perceptions of snakebites in a savanna community of northern Ghana

Abstract

Background Worldwide, snakebite envenomations total ~2.7 million reported cases annually with ~100,000 fatalities. Since 2009, snakebite envenomation has intermittently been classified as a very important ‘neglected tropical disease’ by the World Health Organisation. Despite this emerging awareness, limited efforts have been geared towards addressing the serious public health implications of snakebites, particularly in sub-Saharan Africa, where baseline epidemiological and ecological data remain incomplete. Due to poverty as well as limited infrastructure and public health facilities, people in rural Africa, including Ghana, often have no other choice than to seek treatment from traditional medical practitioners (TMPs). The African ‘snakebite crisis’ is highlighted here using regionally representative complementary data from a community-based epidemiological and ecological study in the savanna zone of northern Ghana. Methodology and findings Our baseline study involved two data collection methods in the Savelugu-Nanton District (in 2019 the district was separated into Savelugu and Nanton districts) in northern Ghana, comprising a cross-sectional study of 1,000 residents and 24 TMPs between December 2008 and May 2009. Semi-structured interviews, as well as collection of retrospective snakebite and concurrent rainfall records from the Savelugu-Nanton District Hospital and Ghana Meteorological Authority respectively over 10-years (1999–2008) were used in the study. Variables tested included demography, human activity patterns, seasonality, snake ecology and clinical reports. Complementary data showed higher snakebite prevalence during the rainy season, and a hump-shaped correlation between rainfall intensity and snakebite incidences. Almost 6% of respondents had experienced a personal snakebite, whereas ~60% of respondents had witnessed a total of 799 snakebite cases. Out of a total of 857 reported snakebite cases, 24 (~2.8%) died. The highest snakebite prevalence was recorded for males in the age group 15–44 years during farming activities, with most bites occurring in the leg/foot region. The highest snakebite rate was within farmlands, most severe bites frequently caused by the Carpet viper ( Echis ocellatus ). Conclusion The relatively high community-based prevalence of ~6%, and case fatality ratio of ~3%, indicate that snakebites represent an important public health risk in northern Ghana. Based on the high number of respondents and long recording period, we believe these data truly reflect the general situation in the rural northern savanna zone of Ghana and West Africa at large. We recommend increased efforts from both local and international health authorities to address the current snakebite health crisis generally compromising livelihoods and productivity of rural farming communities in West Africa.

Diet Breadth Mediates the Prey Specificity of Venom Potency in Snakes

“…Identifying and testing the general patterns between ecological factors and venom functionality and composition at large taxonomic scales can offer a key pathway to understanding the fundamental mechanisms driving the evolution of venom diversity. Ultimately, understanding such mechanisms may contribute to clinical developments [12,54] and aid in bioprospecting [5,55]. From an ecological perspective, understanding the association between diet and venom may aid in our ability to predict the ecological role of venomous predators in rapidly changing ecosystems [56].…”

“…For example, the potential invasiveness of certain venomous species may be mediated by the prey specificity of their venoms, with species with generalist venoms, such as the highly invasive Brown widow (Latrodectus geometricus) and the Noble false widow (Steatoda nobilis), more likely to have venoms which can functionally take advantage of novel prey items [57,58]. Developing clear ecological and evolutionary predictions regarding the composition and functionality of venoms across the animal kingdom can not only offer pathways to understanding nature's complex cocktails, but may also aid in to our ability to manage future medical [5,54,55] and ecological issues relating to venom [5].…”

‘The medicine is not for sale’: Practices of traditional healers in snakebite envenoming in Ghana

“…The rural poor in Sub-Saharan Africa, South Asia and South-East Asia are disproportionally affected, as the most venomous snakes coexist with them in the areas they live and work in [5,8,9]. Bites are incurred most frequently by young and economically active members of communities aged 15-50 years [5,10] and are most often localized on the extremities [9,10].…”

“…In Ghana, a TH might serve an average population of 400 individuals [21] whereas the ratio of university-trained physicians to population is only approximately 1.2/10 000 with significant interregional variation [22]. A household survey in northern Ghana showed that THs tend to nearly half of all snakebite victims in the community [10], a finding similar to a survey of snakebite victims in Sri Lanka, which showed that 43% of victims first sought aid from a TH [18].…”

Health professionals’ over estimation of knowledge on snakebite management, a threat to survival of snake bite victims - A cross-sectional study in Ghana

“…Snakebites have become an event which claims the lives of between 81,000 and 138,000 persons annually most of whom are poor persons in developing countries involved in agriculture to produce food for their nations and for export to bring foreign exchange to their countries [4]. Although some victims of snake bites seek the services of traditional healers many others seek medical assistance from orthodox health facilities where provision of quality healthcare service can ensure the survival of a snakebite victim or eliminate or reduce any post exposure morbidity [6,11].…”