Modeling Cholera dynamics in Kenyan slums: a comprehensive analysis incorporating WASH interventions, vaccination, and treatment

Abstract

Cholera is an acute intestinal disease which has become a global public health concern, especially in regions where water, sanitation and hygiene (WASH) amenities are inadequate. In the period from January - September 2024, Africa reported 127283 cases, with 2268 deaths. In Kenya, cholera has been reported especially in areas with inadequate access to safe water and proper hygienic facilities such as urban informal settlements, large refugee camps, pastoral areas, arid and semi arid lands, areas bordering water bodies and Mwea irrigation scheme. By developing a deterministic mathematical model, this study determined the effectiveness of various WASH interventions in preventing and eradicating cholera in Nairobi slums. The system of ODE’s and the optimal control model were solved numerically using the Runge-Kutta fourth-order method implemented in R, with the forward-backward sweep method applied for the optimal control problem. Scenario analysis was applied to assess the impact of different strategies for controlling the spread of cholera. Results revealed that an integration of all control strategies was necessary and prioritizing water treatment, sanitation, and hygiene promotion can yield substantial public health benefits. The numerical simulations showed that if only one WASH intervention is feasible, improved sanitation and safe fecal sludge management, or water treatment should be prioritized. If two interventions can be implemented, water treatment and waste management should be preferred, followed by hand hygiene and hygienic practices in food handling with sanitation infrastructure. If resources accede three WASH interventions, priority should be given to water treatment, improved sanitation and waste management. The results obtained will provide valuable insights on improvements and steps to take for development of better strategies in management of cholera spread.