Volume 19, Number 8—August 2013
Dispatch
Genotype GI.6 Norovirus, United States, 2010–2012
Table 1
Mode of transmission and setting for norovirus outbreaks reported through CaliciNet, United States, 2010–2012
Characteristic | GI.6 outbreaks, no. (%) n = 141 | Non-GI.6 outbreaks, no. (%), n = 2,777 | Rate ratio (95% CI) |
---|---|---|---|
Mode of transmission | |||
Person-to-person | 81 (57.4) | 1,701 (61.2) | 0.94 (0.81–1.08) |
Foodborne | 28 (19.9) | 311 (11.2) | 1.77 (1.25–2.51) |
Waterborne | 2 (1.4) | 2 (0.1) | 19.70 (2.80–138.80) |
Other | 0 | 15 (0.5) | Not applicable |
Unknown | 30 (21.3) | 748 (26.9) | 0.79 (0.57–1.09) |
Setting | |||
Long-term–care facilities | 51 (36.2) | 1,715 (61.8) | 0.59 (0.47–0.73) |
Schools or daycare centers | 23 (16.3) | 198 (7.1) | 2.29 (1.54–3.40) |
Restaurants | 20 (14.2) | 258 (9.3) | 1.53 (1.00–2.33) |
Parties and events | 17 (12.1) | 153 (5.5) | 2.19 (1.37–3.51) |
Cruise ships | 4 (2.8) | 71 (2.6) | 1.11 (0.41–3.00) |
Hospitals | 1 (0.7) | 109 (3.9) | 0.18 (0.03–1.29) |
Other non–health care settings | 20 (14.2) | 202 (7.3) | 1.95 (1.27–2.99) |
Unknown | 5 (3.5) | 71 (2.6) | 1.39 (0.57–3.38) |