Table 1.
Epidemiological data of the annual seasonal outbreaks of West Nile virus (WNV) infection in Greece, 2010–2022 (total number of diagnosed cases of WNV infection = 1706), total number of neuroinvasive disease (WNND) cases = 1195).
| Variable | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Number of WNV infection cases | 262 | 100 | 161 | 86 | 15 | 0 | 0 | 48 | 317 | 227 | 145 | 59 | 286 |
| Number of symptomatic WNV infection cases | 262 | 100 | 161 | 86 | 15 | 0 | 0 | 48 | 311 | 224 | 142 | 57 | 278 |
| Number of WNND cases | 197 | 75 | 109 | 51 | 14 | 0 | 0 | 28 | 243 | 140 | 116 | 38 | 184 |
| Percentage of WNND cases | 75% | 75% | 68% | 59% | 93% | NA | NA | 58% | 77% | 62% | 80% | 64% | 64% |
| Notification rate of WNND cases (per 100,000 population) | 1.8 | 0.7 | 1.0 | 0.5 | 0.1 | 0 | 0 | 0.3 | 2.2 | 1.3 | 1.1 | 0.4 | 1.7 |
| Number of fatal cases with symptomatic WNV infection | 35 | 9 | 18 | 11 | 6 | 0 | 0 | 5 | 51 | 35 | 23 | 8 | 33 |
| Case fatality among cases with symptomatic WNV infection | 13% | 9% | 11% | 13% | 40% | NA | NA | 10% | 16% | 16% | 16% | 14% | 12% |
| Number of fatal cases with WNND | 33 | 9 | 18 | 10 | 6 | 0 | 0 | 5 | 48 | 33 | 23 | 7 | 33 |
| Case fatality of cases with WNND | 17% | 12% | 17% | 20% | 43% | NA | NA | 18% | 20% | 24% | 20% | 18% | 18% |
| Number of affected a municipalities | 38 | 46 | 42 | 35 | 7 | 0 | 0 | 10 | 86 | 56 | 48 | 18 | 46 |
| Number of affected a NUTS3 regional units | 11 | 21 | 19 | 12 | 4 | 0 | 0 | 6 | 24 | 19 | 16 | 9 | 14 |
| Number of affected a NUTS2 regions | 5 | 7 | 8 | 5 | 3 | 0 | 0 | 3 | 7 | 5 | 4 | 4 | 5 |
| Date of symptom onset of the first case | 6/7 | 16/7 | 20/6 | 2/7 | 5/8 | - | - | 20/6 | 31/5 | 21/6 | 4/7 | 14/7 | 23/6 |
NA: not applicable; a municipalities, regional units, and regions with ≥1 case of WNV infection.