Volume 15, Number 1—January 2009
Research
Selection Tool for Foodborne Norovirus Outbreaks
, Annelies Kroneman, Yvonne van Duynhoven, Hendriek Boshuizen, Wilfrid van Pelt, Marion Koopmans, on behalf of the Foodborne Viruses in Europe Network
Table 1
Consensus list of parameters for optimal reporting of foodborne (viral) outbreaks as defined by expert opinion, and completeness for data collected in the FBVE surveillance database*
| Parameters for outbreak data | Variable | Foodborne outbreak data (% missing ), n = 224 | Other mode outbreak data (% missing), n = 654 |
|---|---|---|---|
| EFSA (confirmed/probable)† | |||
| Type of outbreak: general or household | Yes | 224 (0) | 654 (0) |
| No. human cases‡ | Yes | 217 (3) | 651 (0) |
| No. hospitalizations‡ | Yes | 78 (65) | 295 (55) |
| No. deaths‡ | Yes | 66 (70) | 195 (70) |
| Foodstuff implicated | Yes | 93 (58) | NA‡ |
| Causative agent§ | Yes | 224 (0) | 654 (0) |
| Setting | Yes | 224 (0) | 654 (0) |
| Contributory factors | Yes | 202 (10) | 482 (26) |
| Origin of foodstuff | No | NA | NA |
| Strength of evidence food | Yes | 224 (0) | NA |
| EFSA (thoroughly investigated)† | |||
| Reason reporting | No | NA | NA |
| Laboratory results food | Yes | 202 (10) | NA |
| Place food produced | No | NA | NA |
| Place food consumed/purchased | Descriptive | 106 (52) | NA |
| Age-affected persons | Categorical | 11 (95) | 73 (89) |
| Gender-affected persons | Yes | 27 (88) | 106 (84) |
| Additional information on agent | Yes | 224 (0) | 653 (0) |
| Additional parameters in literature | |||
| Attack rate† | Yes | 121 (46) | 226 (59) |
| Seasonality | Yes | 149 (33) | 484 (26) |
| Duration of the outbreak† | Yes | 90 (60) | 265 (59) |
| Epidemic curve/point source | No | 202 (10) | 496 (24) |
| Sequence or variant | Yes | 224 (0) | 654 (0) |
| Link with other outbreaks | Yes | 22 (90) | 15 (98) |
| Additional parameters VWA experts | |||
| Incubation period | Yes | 51 (77) | 65 (90) |
| Illness in food handlers and their family | Partially | 202 (10) | NA |
| Presence of ill persons in setting | No | NA | NA |
*FBVE, Foodborne Viruses in Europe network; EFSA, European Food Safety Authority; NA, not applicable; VWA, Food and Consumer Products Safety Authority. Parameters listed in italics could not be included in univariate analyses.
†Not restricted to viral.
‡ A systematic retrospective check of Dutch data showed that variables for no. cases involved were reported to the national institute by regional health services when the outbreak was ongoing, and that these numbers were not updated when the outbreak had finished. The same situation was reported for other countries during the telephone survey.
§Inclusion criterion.
1Persons contributing and countries represented: H. Vennema, E. Duizer (the Netherlands); D. Brown, B. Adak, J. Gray, J. Harris, M. Iturriza (United Kingdom); K.-H. von Bonsdorff, L. Maunula, M. Kuusi (Finland); B. Böttiger, K. Mølbak, G. Falkenhorst, C. Johnsen (Denmark); K.-O. Hedlund, Y. Andersson, M. Thorhagen, M. Lysén, M. Hjertqvist (Sweden); P. Pothier, E. Kohli, K. Balay, J. Kaplon, G. Belliot, S. Le Guyader (France); A. Bosch, A. Dominguez, J. Buesa, A. Sanchez Fauquier, G. Hernández-Pezzi (Spain); G. Szücs, G. Reuter, K. Krisztalovics (Hungary); M. Poljsak-Prijatelj, D. Barlic-Maganja, A. Hocevar Grom (Slovenia); F. Ruggeri, I. Di Bartolo (Italy); E. Schreier, K. Stark, J. Koch, M. Höhne (Germany); M. Lynch, B. Foley, P. McKeown, S. Coughlan (Ireland); K. Vainio, T. Bruun (Norway).