Table 1. Prevalence of Listeria spp. in ready-to-eat foods in Tokyo (2000–2012).
| Samples | Period | No. of samples examined | No. of positive samples (%) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| L. monocytogenes | L. innocua | L. seeligeri | L. welshimeri | L. grayi | Listeria spp. | ||||
| Dairy products | |||||||||
| Natural cheese (Soft/semi-soft) | 2000–2005 | 127 | 1 (0.8) | 4 (3.1) | 5 (3.9) | ||||
| 2006–2012 | 161 | 1 (0.6) | 1 (0.6) | ||||||
| Subtotal | 288 | 1 (0.3) | 5 (1.7) | 6 (2.1) | |||||
| Natural cheese (Hard/semi-hard) | 2000–2005 | 217 | 1 (0.5) | 1 (0.5) | |||||
| 2006–2012 | 73 | 0 (0) | |||||||
| Subtotal | 290 | 1 (0.3) | 1 (0.3) | ||||||
| Dehydrated powdered infant formula | 2000–2012 | 39 | 0 (0) | ||||||
| Butter | 2000–2012 | 8 | 0 (0) | ||||||
| Cream | 2000–2012 | 1 | 0 (0) | ||||||
| Total | 626 | 2 (0.3) | 5 (0.8) | 7 (1.1) | |||||
| Ready-to-eat raw meats and meat products | |||||||||
| Ready-to-eat raw meats | 2000–2005 | 83 | 3 (3.6) | 8 (9.6) | 5 (6) | 12 (14.5) | |||
| 2006–2012 | 13 | 0 (0) | |||||||
| Subtotal | 96 | 3 (3.1) | 8 (8.3) | 5 (5.2) | 12 (12.5) | ||||
| Unheated meat products | 2000–2005 | 85 | 13 (15.3) | 6 (7.1) | 2 (2.4) | 19 (22.4) | |||
| 2006–2012 | 43 | 1 (2.3) | 2 (4.7) | 2 (4.7) | 1 (2.3) | 3 (7) | |||
| Subtotal | 128 | 14 (10.9) | 8 (6.3) | 4 (3.1) | 1 (0.8) | 22 (17.2) | |||
| Specifically heated meat products | 2000–2005 | 27 | 3 (11.1) | 3 (11.1) | |||||
| 2006–2012 | 10 | 0 (0) | |||||||
| Subtotal | 37 | 3 (8.1) | 3 (8.1) | ||||||
| Heat treated meat products (packaged after being heat treated) | 2000–2005 | 474 | 2 (0.4) | 4 (0.8) | 1 (0.2) | 5 (1.1) | |||
| 2006–2012 | 617 | 7 (1.1) | 2 (0.3) | 2 (0.3) | 10 (1.6) | ||||
| Subtotal | 1091 | 9 (0.8) | 6 (0.5) | 3 (0.3) | 15 (1.4) | ||||
| Heated meat products (heat treated after being packaged) | 2000–2012 | 57 | 0 (0) | ||||||
| Dried meat products | 2000–2012 | 40 | 0 (0) | ||||||
| Cooked meats | 2000–2005 | 37 | 1 (2.7) | 1 (2.7) | |||||
| 2006–2012 | 5 | 0 (0) | |||||||
| Subtotal | 42 | 1 (2.4) | 1 (2.4) | ||||||
| Total | 1491 | 26 (1.7) | 22 (1.5) | 16 (1.1) | 1 (0.1) | 53 (3.6) | |||
| Ready-to-eat seafood samples | |||||||||
| Fresh fish | 2000–2005 | 38 | 1 (2.6) | 3 (7.9) | 4 (10.5) | ||||
| 2006–2012 | 48 | 4 (8.3) | 7 (14.6) | 4 (8.3) | 1 (2.1) | 11 (22.9) | |||
| Subtotal | 86 | 5 (5.8) | 10 (11.6) | 4 (4.7) | 1 (1.2) | 15 (17.4) | |||
| Shellfish | 2000–2005 | 111 | 1 (0.9) | 1 (0.9) | 1 | 3 (2.7) | |||
| 2006–2012 | 49 | 0 (0) | |||||||
| Subtotal | 160 | 1 (0.6) | 1 (0.6) | 1 (0.6) | 3 (1.9) | ||||
| Boiled seafood | 2000–2012 | 19 | 0 (0) | ||||||
| Roe | 2000–2005 | 79 | 5 (6.3) | 13 (16.5) | 1 (1.3) | 17 (21.5) | |||
| 2006–2012 | 45 | 1 (2.2) | 4 (8.9) | 1 (2.2) | 6 (13.3) | ||||
| Subtotal | 124 | 6 (4.8) | 17 (13.7) | 1 (0.8) | 1 (0.8) | 23 (18.5) | |||
| Delicatessen of seafood | 2000–2005 | 108 | 2 (1.9) | 10 (9.3) | 1 (0.9) | 12 (11.1) | |||
| 2006–2012 | 90 | 2 (2.2) | 1 (1.1) | 1 (1.1) | 4 (4.4) | ||||
| Subtotal | 198 | 4 (2) | 11 (5.6) | 1 (0.5) | 1 (0.5) | 16 (8.1) | |||
| Dried seafood | 2000–2005 | 131 | 5 (3.8) | 9 (6.9) | 12 (9.2) | ||||
| Total | 718 | 21 (2.9) | 48 (6.7) | 7 (1) | 3 (0.4) | 69 (9.6) | |||
| Pickled vegetables | |||||||||
| Pickled vegetables | 2000–2005 | 145 | 3 (2.1) | 3 (2.1) | |||||