By David Evans

PARIS, Mar 29 (Reuters) Poultry confinement in Europe has largely protected domestic flocks from bird flu but as the African wildfowl migration reaches its peak next month, farmers should be braced for more cases, experts today said.

As bird flu spread westwards across the European Union this year, most countries ordered farmers to keep poultry inside. And while there have been many cases in wild birds, France and possibly Sweden, are alone in finding it in a commercial flock.

''It's been a success so far,'' Bernard Vallat, Director General of the World Animal Health Organisation OIE, told Reuters, also stressing the efficiency of veterinary networks.

''If you look at the hundreds of thousands of farms in Europe, there's only been one, or possibly two, cases.'' The results of tests on a farmed duck from Sweden are expected within days. The H5 strain has already been confirmed.

''But now we're waiting for the return of birds from Africa and the Middle East. There's an additional risk although no proof they'll carry the virus to Europe,'' Vallat added.

The wild birds found in Europe with bird flu are believed to have originated in the Black Sea area and were displaced by extreme cold weather earlier this year.

France has found more than 30 wild bird cases, but the country's food safety agency AFSSA has ruled out direct contact between them and farm turkeys infected by H5N1, blaming transmission on a domestic pet, farm equipment or humans.

It has urged tighter security controls.

The European Commission says more cases in farms can be expected but the confinement measures are working.

''We have to learn to live with the fact it (bird flu) is present in wild birds and we may occasionally have outbreaks in commercial poultry, even though we are applying all necessary measures to prevent this,'' spokesman Philip Tod said.

He said EU Health Commissioner Markos Kyprianou had urged all member states to step up vigilance ''in view of the risk of migratory birds bringing the disease back from Africa.'' MIGRATORY RISK? Ornithologists say the number of migrating birds moving between Africa and Europe at this time of the year runs into the billions and is expected to reach its height in April.

But they also point out that the virus in Nigeria has been confined to poultry and that there has been no detected jump to local wild birds. Instead, they highlight the possible role played by the illegal poultry trade in spreading the virus.

''The risk to Europe from migrating birds this spring can be said to be low,'' said Richard Thomas of Birdlife International.

''Currently, there is no evidence the virus has made the jump from poultry to wild birds in Africa. If it does, it's currently an unknown whether an infected migrant bird could travel as far from West Africa to Europe before succumbing,'' he added.

Vallat agreed that the increased risk was hard to quantify.

''The risk is there but it may not be as great as first thought,'' he said, but added there was also a large number of water birds in Egypt that could be heading towards Europe soon.

Thomas said the first migrant birds from Africa arrived in southern Europe from late February/early March. The numbers peak during April and then slow in May and are a trickle by June.

Established migration routes show southeastern Europe to be more at risk, but experts also point out that the Black Sea displacement this year shows countries outside the usual flyways can also be affected.

''Migration routes are not like airplane routes. They depend on the circumstances at the time,'' Vallat said.

REUTERS SY BST1843