Wild birds not ruled out as UK bird flu source

Yahoo News 29 Nov 07;

Wild birds cannot be ruled out as the source of an outbreak of deadly H5N1 bird flu in England, although no evidence they are infected has been found, Britain's acting Chief Veterinary Officer said on Thursday.

Fred Landeg told reporters on Thursday that the first farm infected in the outbreak had been located in an area where wild birds were common and near an ornamental lake which supports 1,000 waterfowl.

He also said the virus also genetically matched most closely a strain isolated from wild birds in the Czech Republic in the middle of 2007.

"We have no other evidence of any other route of infection to this premises to date (other than wild birds)," acting CVO Fred Landeg told a media teleconference following the publication of a preliminary report into the outbreak.

Landeg added, however, that tests taken on fresh droppings from wild birds in the area had so far found no evidence of infection although tests were continuing.

"I think we have to keep an open mind still," he said.

Britain confirmed on November 13 an outbreak of H5N1 bird flu at an organic poultry farm near Diss, Norfolk in eastern England.

The virus subsequently spread to a second farm operated by the same company and which shared the same workforce.

"The poor biosecurity measures employed by the stockmen who care for more than one unit of poultry..resulted in the transmission of infection, certainly to one premises," Landeg said.

The virulent H5N1 strain has killed more than 200 people worldwide since 2003 and millions of birds had either died from it or been killed to prevent its spread.

(Reporting by Nigel Hunt; Editing by Michael Roddy)

Bird flu cause probe inconclusive
BBC News 29 Nov 07;

The preliminary report into the latest outbreak of bird flu in Suffolk concludes that wild birds "may have been" the main source of infection.

But no evidence has yet been found to support this theory.

The report also found that poor biosecurity was practised by some of the staff on the farm where the outbreak occurred on 11 November.

This is thought to be the probable reason for the disease spreading to another farm.

The virulent H5N1 strain of the virus, a variant capable of being transmitted to humans, was first discovered at Redgrave Park Farm near Diss, where all 6,500 birds were slaughtered.

The disease was later also confirmed to have reached the nearby Hill Meadow Farm at Knettishall - 9,000 turkeys were culled there.

Two theories

The report concludes that the disease has a very close genetic match with an outbreak of H5N1 in the Czech Republic in the summer.

It says that there are two main theories about how the disease was introduced to the UK - either via contamination from people from a country with an undisclosed infection in their domestic flocks, or infected wild birds.

There is currently no evidence to support either theory.

"As there are no epidemiological links with domestic poultry in central Europe, the molecular genetic results suggest that wild birds may have introduced the virus into Suffolk from Europe," the report said.

The Department for Environment, Food and Rural Affairs (Defra) says the disease was discovered in an area where wild birds were relatively common and was notably near to an ornamental lake which supports some 1,000 waterfowl.

The affected poultry were free-range - meaning they had access to the outdoors and may have been at greater risk of catching the disease.

H5N1 infection has not been detected in wild birds nor have any incidents of high mortality been observed in the area, according to the report.

But it added that wild birds, most likely migratory species from central Europe, cannot be ruled out as the source of infection.

Poor biosecurity

The report also said poor biosecurity was employed by stockmen who worked at Redgrave Park Farm and on other farms in the area.

Simple measures to prevent the transmission of infection between premises were not followed, it said.

Such measures include changing clothing between premises, disinfection of Wellington boots, the disinfection between premises of buckets for the distribution of feed, and the carriage and handling of dead birds.

Gressingham Foods' subsidiary Redgrave Poultry, which runs both Redgrave Park Farm and Hill Meadow said it had identified several changes that were needed when it purchased the farms at the start of the year.

It said: "Due to our commitments to our customers and the lack of available organic land, it was simply not practical to make all of the planned changes for this season.

"We believe in the highest standards of organic and free range farming for these production systems, so we have looked for lessons from the recent outbreak and have identified a number of improvements that we are implementing."

Dr Mark Avery, conservation director for the RSPB, said imported poultry could have been the cause of the Suffolk outbreak.

"A migrating bird could have carried the disease here without showing symptoms but imported poultry could have done exactly the same.

"Defra and the poultry industry should be doing more to protect wild birds from coming into contact with infected farmed birds."

Suffolk previously had an H5N1 outbreak at a turkey farm in February, but the report found there was no connection that incident.