OBJECTIVETo conduct a quantitative risk assessment for Listeria monocytogenes in bulk cooked meat products in China.

METHODSThe data on the contamination level of Listeria monocytogenes in cooked meat products was from national foodborne disease surveillance network, involving a total of 841 samples. All the samples were detected by a qualitative method and 97 samples among them were detected using a quantitative method. The intake data of cooked meats was from Chinese National Nutrition and Health Survey in 2002 and population data in the monitoring sites was collected from National Bureau of Statistics in 2008 to estimate the composition of the population of different ages, which would be the base of assessing the probability of listeriosis in the different subpopulations. Using @Risk software to estimate the risk of listeriosis caused by consuming deli meats for different subpopulation (0 - 4 years old, 5 - 64 years old and 65 years and older) by quantitative risk assessments which involved hazard identification, hazard characterization, exposure assessment and risk characterization and conduct sensitivity analysis.

RESULTSThe contamination level of Listeria monocytogenes in the most of samples (96.08%, 808/841) was less than 3 MPN/g (0.5 lg MPN/g), and the average concentration of Listeria monocytogenes was -0.61 lg CFU/g (90%CI: -1.22 - 0.46 lg CFU/g). Estimated servings of cooked meat consumption for 0 - 4, 5 - 64 and 65 years and older were 5.52 × 10(9), 8.99 × 10(10), 1.01 × 10(10), respectively. Estimated number of cases (median) of listeriosis each year per million people caused by consuming cooked meats in young (0 - 4 years old), intermediate age (5 - 64 years old) and elderly (65 years and older) population were 5.53 × 10(-3), 1.72 × 10(-4), 7.57 × 10(-3), respectively. Results of sensitivity analysis showed that contamination level at retail, serving size of cooked meats, storage time at home, storage temperature and ERG at 5°C were positive factors for the risk of listeriosis (r value was 0.607, 0.408, 0.339, 0.259, 0.183 respectively, P < 0.05).

CONCLUSIONCooked meat products in bulk is a risk food, which could cause listeriosis. Contamination level of Listeria monocytogenes in cooked meat products in bulk is the top risk factor for the listeriosis.