[Active surveillance on Listeria monocytogenes in seven kinds of food in 11 provinces of China in 2001].

Objective: To carry out national active surveillance on Listeria monocytogenes in foods in China.

Methods: Four thousand and thirty-four random samples from raw meat, meat product, raw milk, vegetable, yoghurt, icecream and aquatic product were collected in 11 provinces (cities), and examined for Listeria monocytogenes according to the national standard method and confirmed by BAX system (DuPont Qualicon, Wilmington, DE).

Results: Seventy isolates four kinds of foods in seven provinces were found to have LM according to the national standard method with a total isolate rate of 1.74%. In Fujian, the rate was higher than in the other provinces. Raw meat was found to be most heavily contaminated in seven kinds of foods. Comparing to national standard method, BAX system showed good sensitivity (> 98%) and specificity (> 97%).

Conclusion: In each province seven kinds of food were all contaminated by Listeria monocytogenes to some degrees, suggesting that local sanitary surveillance should be strengthened. BAX system can be used to correctly and quickly screen Listeria monocytogenes.