Volume 7, Number 6—December 2001
Research
Effect of Prevention Measures on Incidence of Human Listeriosis, France, 1987-1997
Table 4
Proportion of ready-to-eat foods contaminated with Listeria monocytogenes (Lm) by food category, level of contamination, and period, France, 1993-1996
1993-94 | 1995-96 | Percent change (%) | pa | |
---|---|---|---|---|
Ready-to-eat meat products | ||||
Number of samples | 1,533 | 1,750 | ||
% of food contaminated by Lm | ||||
<100 CFU/gb | 11 | 8.5 | -23 | 0.02 |
>100 CFU/g | 1.6 | 0.7 | -56 | 0.03 |
Total | 12.6 | 9.2 | -28 | 0.003 |
Dairy products | ||||
Number of samples | 1,695 | 1,846 | ||
% of food contaminated by Lm | ||||
<100 CFU/gb | 3.2 | 2.7 | -16 | ns |
>100 CFU/g | 2.2 | 1.3 | -41 | 0.03 |
Total | 5.4 | 4 | -26 | 0.03 |
Prepared salads | ||||
Number of samples | 1,740 | 1,426 | ||
% of food contaminated by Lm | ||||
<100 CFU/gb | 4.9 | 3.3 | -33 | 0.02 |
>100 CFU/g | 0.3 | 0.3 | 0 | ns |
Total | 5.2 | 3.6 | -31 | 0.02 |
Seafood-fish products | ||||
Number of samples | 841 | 1,125 | ||
% of food contaminated by Lm | ||||
<100 CFU/gb | 9.3 | 11.4 | +22 | ns |
>100 CFU/g | 0.7 | 0.5 | -29 | ns |
Total | 10 | 10.3 | +18 | ns |
Total no. of samples | 5,809 | 6,147 | ||
% of food contaminated by Lm | ||||
<100 CFU/gb | 6.6 | 5.9 | -10 | ns |
100 CFU/g | 1.3 | 0.8 | -38 | 0.007 |
Total | 7.9 | 6.7 | -16 | 0.008 |
aChi-square test with Yates correction or Fisher exact test.
bLevels of contamination <100 CFU/g but greater than zero.