British, Hungarian bird flu outbreaks linked

LONDON, Feb 13 (Reuters) Tests on H5N1 bird flu viruses found in Britain and Hungary showed they were genetically almost identical and the most likely transmission route was from poultry to poultry, Britain said today.

The establishment by scientists in Britain of a direct link between the two outbreaks came the same day Hungary said it had found no evidence poultry there could have transmitted the virus to Britain.

The two countries have been feuding over the likely source of the British contamination, which led to the destruction of tens of thousands of turkeys in Britain. Hungarian officials disputed British statements earlier this week that the virus probably came from turkey meat imports, rather than wild birds.

However, Britain stressed that while the outbreaks were linked it had not found any evidence of illegal or unsafe movements of poultry products from Hungary to Britain and was still investigating all possible routes of transmission.

''We have not ruled anything out,'' Britain's Department for Environment, Food and Rural Affairs (DEFRA) said in a statement.

A case of H5N1 was discovered in geese in southeast Hungary last month. The tests at Britain's Veterinary Laboratory Agency aimed to establish whether there was a direct link to a similar outbreak this month at a turkey farm in Suffolk, England.

DEFRA said the final results showed a very high similarity (99.96 pct) at the whole genome level.

''These results indicate that the viruses are essentially identical,'' the statement said.

''These levels of identity are much closer than with other Asian lineage H5 viruses for which data is available, including those isolated from wild birds in Europe in 2005/06,'' the VLA's chief avian virologist Ian Brown said.

Britain's deputy chief veterinarian Fred Landeg said the working hypothesis, based on the work of the VLA, was that the virus had most likely been transmitted from poultry to poultry.

''I must reiterate that we are not discounting any line of inquiry and this is an on-going investigation,'' he said.

The EU commission also said that while the tests showed the outbreaks were directly linked, that in itself did not explain how the strain came to Britain.

''We are not going to speculate, nor should anybody, as to how it arrived as this is still part of an ongoing investigation. But we reiterate our view that the Hungarian authorities have acted properly and took the right measures,'' said Philip Tod, spokesman for EU Health Commissioner Markos Kyprianou.

Europe's largest turkey producer, Bernard Matthews, reopened the plant hit by the outbreak earlier this month today after 160,000 turkeys at a nearby farm were destroyed.

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