Volume 19, Number 8—August 2013
CME ACTIVITY - Research
Effects and Clinical Significance of GII.4 Sydney Norovirus, United States, 2012–2013
Table 1
Number and percentage of norovirus gastroenteritis outbreaks, by genotype, strain, setting, and mode of transmission in Minnesota, Ohio, Oregon, Tennessee, and Wisconsin, August 2012–April 2013*
Outbreak | No. (%) outbreaks with sequence data |
No. (%) outbreaks with no sequence data, n = 279 | Total no. (%), N = 637 | ||
---|---|---|---|---|---|
GII.4 Sydney, n = 226 | Non–GII.4 Sydney, n = 132 | RR (95% CI) | |||
Mode of transmission | |||||
Person to person | 172 (76.1) | 93 (70.5) | 1.08 (0.95–1.23) | 216 (77.4) | 481 (75.5) |
Foodborne | 35 (15.5) | 28 (21.2) | 0.73 (0.47–1.14) | 28 (10.0) | 91 (14.3) |
Water | 0 | 1 (0.8) | NA | 0 | 1 (0.2) |
Environmental | 0 | 2 (1.5) | NA | 0 | 2 (0.3) |
Other/unknown |
19 (8.4) |
8 (6.1) |
1.39 (0.62–3.08) |
35 (12.5) |
62 (9.7) |
Setting | |||||
LTCF/hospital | 170 (75.2) | 63 (47.7) | 1.58 (1.30–1.91) | 189 (67.7) | 422 (66.2) |
School/CCC | 4 (1.8) | 28 (21.2) | 0.08 (0.03–0.23) | 49 (17.6) | 81 (12.7) |
Restaurant/banquet facility | 35 (15.5) | 25 (18.9) | 0.82 (0.51–1.30) | 23 (8.2) | 83 (13.0) |
Other/multiple settings† | 14 (6.2) | 13 (9.8) | 0.63 (0.31–1.30) | 15 (5.4) | 42 (6.6) |
Unknown | 3 (1.3) | 3 (2.3) | 0.58 (0.12–2.85) | 3 (1.1) | 9 (1.4) |
*RR, rate ratio; NA, not available; LTCF, long- term care facility; CCC, childcare center.
†Other settings include the following: private home (n = 15), noncafeteria workplace (n = 7), church (n= 2), other religious location (n = 2), hotel (n = 2), party (n = 3), apple orchard (n = 1), camp (n = 1), football tournament (n = 1), ship (n = 1), indoor playground (n = 1), movie theater (n = 1), trip to relatives (n = 1), other unspecified (n = 1), and multiple settings (n = 3).