Quantitative Risk Assessment of Salmonella in Broiler Chicken Along the Value Chain in Oyo State

Salmonella contamination in broiler chicken is a leading cause of foodborne illness globally, and the poultry value chain in Oyo State, South West Nigeria, presents multiple contamination and cross-contamination risk points from farm through retail to consumer. This study conducts a quantitative microbiological risk assessment of Salmonella in broiler chicken using a farm-to-fork exposure assessment model adapted to the conditions of the Ibadan poultry value chain. Prevalence and concentration data were collected from six stages: farm (live birds), slaughter and evisceration, market storage, retail handling, consumer transportation, and household storage and cooking. Salmonella were enumerated and serotyped from 200 samples per stage. Consumer behaviour data on chicken handling, cooking temperatures, and consumption patterns were collected from 300 households through structured questionnaires. A stochastic simulation model was developed using Monte Carlo simulation with 10,000 iterations. Dose-response was modelled using the Beta-Poisson model. Results estimated a mean probability of illness per serving of 2.8 times 10 to the negative 4, with retailing under ambient conditions and inadequate cooking being the principal risk amplification points. Sensitivity analysis identified holding temperature at retail and internal cooking temperature as the variables most strongly influencing risk outcome. The study contributes to quantitative risk assessment methodology for the Nigerian poultry sector. Findings are intended for the Oyo State Ministry of Agriculture, food safety regulatory bodies, and poultry industry associations. Keywords: quantitative risk assessment, Salmonella, broiler chicken, food safety, Monte Carlo simulation