Table 1. Characteristics of Escherichia coli O157 outbreaks by transmission mode and food category, United States, 2003–2012*.
| Transmission source | Outbreaks (% of all outbreaks) | Illnesses (median outbreak size) | Hospitalizations (% of all illnesses) | Physician-diagnosed HUS (% of all illnesses) | Deaths (% of all illnesses) |
|---|---|---|---|---|---|
| Food | 255 (65) | 3,667 (6) | 1,035 (29) | 209 (6) | 25 (0.7) |
| Beef | 78 (20) | 1,144 (7) | 316 (28) | 67 (6) | 5 (0.4) |
| Poultry† | 1 (0) | 60 | 5 (8) | 0 | 0 |
| Other meat | 7 (2) | 39 (4) | 12 (31) | 4 (10) | 0 |
| Dairy | 16 (4) | 140 (6) | 52 (37) | 22 (16) | 0 |
| Leafy vegetables | 29 (7) | 922 (16) | 321 (35) | 53 (6) | 7 (0.8) |
| Fruits | 6 (2) | 57 (8) | 20 (35) | 5 (9) | 6 (10.5) |
| Sprouts | 3 (1) | 35 (13) | 4 (11) | 0 | 0 |
| Nuts | 1 (0) | 8 | 3 (38) | 0 | 0 |
| Other foods‡ | 29 (7) | 580 (11) | 123 (21) | 24 (4) | 0 |
| Food unknown | 85 (22) | 682 (5) | 179 (26) | 32 (5) | 10 (1.5) |
| Animal contact | 39 (10) | 552 (6) | 127 (23) | 51 (9) | 2 (0.4) |
| Person-to-person | 39 (10) | 322 (5) | 45 (14) | 24 (7) | 2 (0.6) |
| Water | 15 (4) | 154 (6) | NA | NA | 1 (0.6) |
| Other or unknown | 42 (10) | 233 (4) | 65 (28) | 15 (6) | 3 (1.3) |
| Total | 390 (100) | 4,928 (6) | 1,272 (27§) | 299 (6§) | 33 (0.7) |
*HUS, hemolytic uremic syndrome; NA, not available. †Poultry was thought to be cross-contaminated by ground beef http://www.ct.gov/dph/lib/dph/infectious_diseases/ctepinews/vol29no5.pdf. ‡Outbreaks transmitted from other foods were 2 each of: guacamole, pico de gallo, salsa, and potato salad; and 1 each of: cookie dough; alfalfa sprouts and iceberg lettuce; baked beans and unknown fruit; meatballs, steak and green salad; cantaloupe and hamburger; lamb and beef; lettuce and green grapes; lime and bean dip; macaroni; Mexican wheat snack; sandwich; seafood; vegetable-based salad; pepperoni; jerky; multiple foods. Agencies sometimes report >1 food vehicle when epidemiologic evidence cannot distinguish between them even when it is likely that only one was the source. §Excludes 154 illnesses from the denominator that were associated with waterborne disease outbreaks because no data was collected for hospitalization and physician-diagnosed HUS cases for this transmission mode.