Experts are still battling to contain an outbreak of bird flu in North Wales as more test results are expected to show the virus has spread
Experts are still battling to contain an outbreak of bird flu in North Wales as more test results are expected to show the virus has spread.
A total of 12 people are so far thought to have contracted avian flu since it was discovered at a farm in Corwen last week.
The disease is the "very mild" H7N2 strain rather than the more virulent H5N1 variety.
It is thought to have spread from infected chickens which were traded at the Chelford Market in Cheshire two weeks ago.
The 15 Rhode Island Red chickens were bought at the market by the farm's owners but all later died.
Restrictions have also been put on a second farm in the Llyn Peninsula, around 45 miles from the Corwen property, due to links with the Chelford Market.
A dozen schoolchildren and two members of staff at Ysgol Henllan primary school near the farm have been offered courses of the anti-flu drug Tamiflu as one of the pupils is thought to have contracted the virus.
Health officials have sent letters to parents inviting them to a meeting to discuss any concerns.
But they cannot rule out the possibility that the disease has spread from person to person and are stressing that inquiries are ongoing.
A National Public Health Service for Wales spokesman said: "Person to person spread would be very unusual but limited spread of this type has been seen elsewhere in the past in some cases of bird flu."