Volume 26, Number 10—October 2020
CME ACTIVITY - Synopsis
Lessons Learned from a Decade of Investigations of Shiga Toxin–Producing Escherichia coli Outbreaks Linked to Leafy Greens, United States and Canada
Table 2
Leafy green type | Outbreaks with information for type of leafy green† | Outbreaks with single known type of leafy green implicated | Outbreak-related illnesses attributed to outbreak with single type of implicated leafy green | |
---|---|---|---|---|
Romaine | 16 (40) | 13 (54) | 617 (84) | |
Iceberg | 7 (18) | 4 (17) | 54 (7) | |
Spinach | 5 (13) | 4 (17) | 32 (4) | |
Cabbage | 1 (3) | 1 (4) | 16 (2) | |
Kale | 1 (3) | 1 (4) | 7 (1) | |
Green leaf | 1 (3) | 1 (4) | 5 (0.7) | |
Butter lettuce | 1 (3) | 0 | 0 | |
Radicchio | 1 (3) | 0 | 0 | |
Spring mix | 1 (3) | 0 | 0 | |
Unknown |
11 (28)‡ |
0 |
0 |
|
Total | 40 | 24 | 731 |
*Values are no. (%) except as indicated. STEC, Shiga toxin–producing Escherichia coli
†More than 1 type of leafy green may have been reported for a given outbreak.
‡This includes two outbreaks that occurred in both the US and Canada. In 2015, the US investigation identified romaine lettuce as the outbreak source, and the Canadian investigation was not able to determine a specific type of leafy green. In 2017, the Canadian investigation linked an outbreak of STEC O157 to romaine lettuce, and the US investigation did not result in enough epidemiologic evidence to implicate a specific type of leafy green. For the purposes of this study, the leafy green type for these outbreaks was classified as unknown. For 1 outbreak, multiple leafy green types, including kale, spinach, and romaine, were reported and traced back but the leafy green type remained unknown.