Mapping Snakebite Risk in Ghana and Rwanda: Using Primary Data Collection and Geostatistical Techniques to Develop an Approach to Risk Estimation for Snakebite

Introduction

Background Snakebite was declared a neglected tropical disease (NTD) by the World Health Organization (WHO) in 2017, reflecting its global public health impact. Over 95% of cases occur in tropical settings, predominantly in low- and middle-income countries (LMICs) in South Asia, sub-Saharan Africa and South America and the greatest burden falls upon the most vulnerable populations, including those living in less robust housing, agricultural workers on low incomes, and children. Snakebite envenoming is thought to cause up to 138,000 deaths per year and non-fatal bites lead to considerable health burden through physical disability, such as severe scarring and limb amputation, psychological impact, and social stigma, isolation and economic loss resulting from these consequences. To help address the public health impact of snakebite, WHO launched its strategy Snakebite Envenoming - A Strategy for Prevention and Control in 2019, with an ambitious aim to halve death and disability from the condition by 2030.

Snakebite prevention and management is an evolving field. Significant work is needed to develop effective treatments against envenomation by the full range of medically important snake species at a cost that is affordable for the populations in need. Despite such challenges, approaches to help prevent and manage snakebite do exist and can be effective in reducing the burden of snakebite in high-risk communities. Prevention activities focus on building knowledge within communities on the dangers of snakebite envenoming, education regarding how to avoid snakes within the home and at work, including the use of protective footwear, and promotion of the importance of seeking effective medical treatment, if bitten, rather than relying upon traditional remedies. When a person experiences a snakebite, management of the victim may cover a range of measures including simple first aid techniques such as immobilisation and application of pressure bandages, supportive care in a medical facility, and, if needed and available, treatment with antivenom that is effective against the species of snake responsible.

High quality data on snakebite burden are essential for ensuring that the resources for treatment and prevention are targeted towards the populations most at risk. However, such data are sparsely reported, with data availability especially limited across countries in sub-Saharan Africa (SSA). Most snakebite data from SSA come from health facility surveys and reporting. However, snakebite is not widely designated a notifiable condition and routine health facility data are often either not reported nationally or are done so inconsistently. Where health facility data are available, they are likely to underestimate snakebite burden as they do not capture the many snakebite victims either not reaching health facilities in time or seeking traditional treatment in the community. High-quality cross-sectional community surveys can help in the assessment of snakebite burden at a fine scale, however very few have been conducted in SSA to date, and as they require significant time and resources and may be difficult to undertake in areas with inaccessible terrain, weak healthcare infrastructure or political instability, they do not provide a feasible alternative for estimating burden at the scale needed. Better data are needed to characterise snakebite epidemiology to inform risk mitigation, prevention or elimination strategies and without robust surveillance systems, an alternative approach to effectively identifying high risk areas is needed.

Problem statement and justification for the study