Table 1.
Characteristics of outbreaks, outbreak establishments, and outbreak investigations, single setting outbreaks – National Environmental Assessment Reporting System (NEARS), 2009–2013a
| n | % | |
|---|---|---|
| Outbreak characteristics | ||
| Primary etiologic agent identified (N = 297) | ||
| Yes | 210 | 70·7 |
| No | 87 | 29·3 |
| Outbreak type (N = 210) | ||
| Viral | 143 | 68·1 |
| Bacterial | 55 | 26·2 |
| Toxin | 12 | 5·7 |
| Food vehicle identified (N = 270) | ||
| Yes | 151 | 55·9 |
| No | 119 | 44·1 |
| Contributing factor identified (N = 297) | ||
| Yes | 194 | 65·3 |
| No | 103 | 34·7 |
| Contributing factor type (N = 194)b | ||
| Contamination | 165 | 85·1 |
| Proliferation | 38 | 19·6 |
| Survival | 20 | 10·3 |
| Outbreak establishment characteristics | ||
| Establishment type (N = 297) | ||
| Restaurant | 259 | 87·2 |
| Caterer | 5 | 1·7 |
| Nursing home | 4 | 1·4 |
| Restaurant in a supermarket | 4 | 1·4 |
| Camp | 3 | 1·0 |
| Workplace cafeteria | 3 | 1·0 |
| Grocery store | 2 | 0·7 |
| School foodservice | 2 | 0·7 |
| Other | 15 | 5·1 |
| Menu type (N = 297) | ||
| American | 180 | 60·6 |
| International or ethnic | 117 | 39·4 |
| Establishment food preparation process type (N = 297) | ||
| Complex – a food item requires a kill step and includes holding beyond same day service or some combination of holding, cooling, re-heating, and freezing | 253 | 85·2 |
| Cook serve – a food item is prepared for same day service and involves a kill step | 26 | 8·7 |
| Prep serve – all food items are prepared and served without a kill step | 18 | 6·1 |
| Establishment serves raw or undercooked food (N = 297) | ||
| Yes | 82 | 27·6 |
| No | 215 | 72·4 |
| Ownership type (N = 267) | ||
| Chain | 82 | 30·7 |
| Independent | 185 | 69·3 |
| Meal preparation location (N = 266) | ||
| All meals prepared on location | 234 | 88·0 |
| Meals fully or partially prepared at another location | 32 | 12·0 |
| Approximate number of meals served daily (N = 254) | ||
| 1–150 | 84 | 33·1 |
| >150 | 170 | 66·9 |
| Investigation characteristics | ||
| Time to contact outbreak establishment to schedule an environmental assessment (N = 283) | ||
| Same day | 212 | 74·9 |
| 1–5 days | 61 | 21·6 |
| 6–27 days | 10 | 3·5 |
| Number of visits made to outbreak establishment to complete the environmental assessment (N = 285) | ||
| 1 or 2 | 133 | 46·7 |
| ⩾3 | 152 | 53·3 |
a
Denominators vary because of missing data for the explanatory variables.
b
Percentages add to more than 100 because outbreaks could have more than one contributing factor.