Growth Simulation and Risk Assessment of Listeria monocytogenes in Chicken Liver at Refrigeration Condition

Listeria monocytogenes is an important emerging foodborne pathogen with infections causing high mortality rates (20-30%). It can cause sporadic but serious cases of listeriosis especially among pregnant women and the elderly. Emergence of multiple antibiotic resistant strains further complicate treatment of listeriosis cases. The goals of present study include to assess the risk of listeriosis among general population, pregnant women, elderly and immunocompromised from contaminated chicken liver consumption in Malaysia. L. monocytogenes growth data at temperature 4oC were used to determine the probability of listeriosis from chicken liver consumption using exponential model. The data obtained was used to calculate probability of infection among vulnerable groups (pregnant women, elderly and immunocompromised). Monte Carlo simulation with 10 000 iteration was used to determine the distribution of expected cases and rate of infection. Monte Carlo simulation showed L. monocytogenes in chicken liver at refrigerated increased by 20.50 fold. Immunocompromised patient was estimated to show the highest risk of listeriosis followed by pregnant women, elderly and general population. This study concluded that L. monocytogenes presence in chicken liver and inadequate safe food practices that cause cross contamination pose significant risk of listeriosis among the consumers.