Table 2. Spatio-temporal clusters detected by the space–time permutation scan test for 218 HPAI-H5N8 outbreaks reported in French poultry holdings from 28 November 2016–23 March 2017.
| Cluster number | Cluster centre | Radius (km)a | Time frame | Number of outbreaks | Expected outbreaks | Observed-to-expected ratio | p value |
|---|---|---|---|---|---|---|---|
| 1 | Tarn | 16.5a | 28 Nov 2016–10 Dec 2016 (13 days) |
8 | 0.4 | 21.8 | 0.0000 |
| 2 | Gers | 18.9 – 28.4a | 11 Dec 2016–4 Jan 2107 (25 days) |
53 | 16.8 | 2.6 | 0.0000 |
| 3 | Landes | 8.5 – 17.0a | 8 Jan 2017–17 Jan 2017 (10 days) |
15 | 1.9 | 7.0 | 0.0001 |
| 4 | Hautes-Pyrénées | 7.6 – 11.4a | 13 Jan 2017–14 Jan 2017 (2 days) |
8 | 0.22 | 22.7 | 0.0090 |
| 5 | Landes | 35.1 – 52.7a | 3 Feb 2017–22 Feb 2017 (20 days) |
51 | 13.6 | 3.3 | 0.0000 |
HPAI: highly pathogenic avian influenza.
a The area in which cluster 1 occurred was characterised as being within a circle, while the areas of the other clusters were characterised as being inside ellipsoids.