Volume 9, Number 1—January 2003
Research
Two Epidemiologic Patterns of Norovirus Outbreaks: Surveillance in England and Wales, 1992–2000
, Goutam K Adak*, Mark Reacher*, and David W.G. Brown*
Table 1
Primary modes of transmission of Norovirus outbreaks, England and Wales, 1992–2000
| Setting of outbreak | Foodbornea | Person to persona | Other/unknowna | Total |
|---|---|---|---|---|
| Hospital | 10 (1.3) | 716 (95.0) | 28 (3.7) | 754 |
| Residential facilities | 33 (4.5) | 658 (91.0) | 32 (4.4) | 723 |
| School | 4 (5.5) | 65 (89.0) | 4 (5.5) | 73 |
| Food outlet | 70 (66.7) | 23 (21.9) | 12 (11.4) | 105 |
| Hotel | 42 (28.6) | 94 (63.9) | 11 (7.5) | 147 |
| Other |
25 (33.8) |
43 (58.1) |
6 (8.1) |
75 |
| Total | 184 (9.9) | 1,599 (85.2) | 93 (5.0) | 1,877 |
aNo. of outbreaks (% of all outbreaks in setting).
Appendix: Surveillance and analysis definitions
Outbreak: an incident in which two or more people, thought to have a common exposure, experience a similar illness or proven infection, at least one of them being ill (22).
General outbreak: an outbreak that affects members of more than one household, or residents of an institution (36).
General outbreak of Norovirus: a general outbreak in which Norovirus is determined to be the causative agent by electron microscopy, RT-PCR, or enzyme immunoassay in one or more affected persons.
Residential facilities: includes residential homes, which provide some assistance in day-to-day living, and nursing homes, which provide care for persons whose infirmity or illness requires nursing care on a regular basis.
Food outlets: commercial food retailers including restaurants, pubs, bars, cafeterias, mobile food vendors, and caterers.