Europe is expecting more outbreaks of avian influenza in the next few weeks as wild birds migrate southward, said Matthew Stone, deputy director general of the World Organization for Animal Health. Eight European countries and Israel have founds cases of the highly contagious H5N8 strain of bird flu in the past few weeks and some countries are ordering that poultry flocks be kept indoors to avoid the disease from spreading.

Most outbreaks involved wild birds, but Germany, Hungary, and Austria have now reported cases in domestic duck and turkey farms where all poultry had to be culled. Switzerland, Poland, the Netherlands, Denmark and Croatia have also reported outbreaks of H5N8. France currently has been spared by H5N8 thus far.

“From the level of exposure that we have seen to date, I would expect more detections, hopefully only in wild birds, but it is certainly possible that the presence of the virus in wild birds will create an opportunity for exposure in domestic poultry,” Stone told Reuters in an interview.

Several countries have ordered farmers to keep poultry indoors and other countries have extended precautionary measure to prevent the spread of the virus.  The H5N8 virus has not been detected on British Farms yet. However, England’s chief vet, Nigel Giggens, recently declared a “prevention zone” for England that requires commercial and individual bird keepers to keep their birds inside for 30 days or take steps to separate them from wild birds.

Wild birds can carry the virus without showing symptoms of it and transmit it to domestic poultry. The H5N8 virus has never been detected in humans but led to the culling of millions of farm birds in Asia and Europe in 2014.