Table 1
Number and type of tested flocks per species and production category
| Type of poultry holding tested | Laying hens | Broiler chickens | Fattening turkeys | Fattening geese | Breeding geese | Fattening ducks | Breeding ducks | Guinea fowl |
|---|---|---|---|---|---|---|---|---|
| Flocks suspected of being infected and TTE (passive surveillance)1 | 24 | 25 | 34 | 3 | 2 | 58 | 4 | 3 |
| Contact (sick1 or holdings healthy birds2) | 1 | 0 | 8 | 0 | 0 | 4 | 0 | 0 |
| Flocks assumed free of slaughterhouses HPAI before shipment or within to restriction zones2 | 1 | 146 | 18 | 0 | 0 | 40 | 0 | 1 |
| Flocks of HPAI assumed after re-free population3 | 3 | 5 | 27 | 5 | 1 | 9 | 6 | 0 |
| TOTAL | 29 | 176 | 87 | 8 | 3 | 111 | 10 | 4 |
1 organs from at least 5 birds (dead or sick) as well as oropharyngeal and cloacal swabs from at least 20 birds per flock (dead or sick)
Fig. 1
Location of HPAI H5N8 outbreaks in Poland between 31 December 2019 and 31 March, 2020 (white dots: commercial farms; purple dots: backyard holdings; asterisk: wild bird)
Table 2
A summary of HPAI outbreaks in poultry in Poland reported between 31 December 2019 and 31 March 2020
| Production type | Province | Number of outbreaks | Total |
|---|---|---|---|
| fattening turkeys | Lubelskie Zachodniopomorskie Wielkopolskie Warmińsko-Mazurskie Lubuskie | 5 1 2 2 2 | 12 |
| fattening ducks | Wielkopolskie Opolskie Łódzkie Śląskie | 3 1 5 1 | 10 |
| breeding ducks | Wielkopolskie Łódzkie | 1 1 | 2 |
| breeding geese | Wielkopolskie Śląskie | 1 1 | 2 |
| laying hens | Wielkopolskie | 1 | 1 |
| guinea fowl | Lubelskie | 1 | 1 |
| backyard holdings (mostly chickens) | Lubelskie Dolnośląskie Wielkopolskie Śląskie | 2 2 2 1 | 7 |
| Total | 35 | ||
Fig. 2
Maximum clade credibility phylogenetic tree of the HA gene segment of H5N8 viruses sequenced in the present study and sequences available in the EpiFlu GISAID database. The European H5N8 viruses from the 2018/2020 epidemic are highlighted with blue and green. The names of Polish strains are coloured red and are labelled according to the legend. The posterior probability values are indicated next to the nodes