Mathematical analysis and numerical simulation of campylobacteriosis dynamics: assessing the roles of house flies and contaminated food products as mechanical vectors

Globally, food-borne campylobacteriosis is a major cause of bacterial gastroenteritis, disproportionately affecting impoverished areas. Inadequate sanitation infrastructure in these settings leads to abundant house flies, potentially contaminating food and surfaces and increasing the spread of infections, such as campylobacteriosis. This paper addresses the underexplored direct transmission routes of campylobacteriosis: undercooked poultry consumption, mechanical vectors such as house flies and contaminated food products. We developed a mathematical model to investigate campylobacteriosis transmission dynamics through these pathways and to inform control measures. Our model includes human, vector (house fly) and food compartments, capturing indirect transmission via bacterial shedding, environmental contamination and mechanical vector transfer. We examined the stability of both disease-free and endemic equilibria through analytical and numerical simulations based on the basic reproduction number. Uncertainty and sensitivity analyses identified key parameters driving disease persistence. Mechanical vectors significantly sustain transmission, suggesting targeted control strategies. Public health interventions should reduce campylobacteriosis by minimising vector contact via awareness programmes and fumigation and addressing environmental contamination. © 2026 The Authors