Migrating Flocks Not Carrying Bird Flu to Europe

May 11, 2006 — -- Europeans have been pleasantly surprised to learn that no avian flu virus has been detected in flocks of migratory birds that flew south to Africa last fall and then back over Europe this spring, international health officials say.

This is a major turnaround that defies the dire predictions from many health officials of an impending pandemic.

Scientists at Wetlands International who monitor avian influenza and water birds report that "millions of water birds have already migrated from Asia to West Asia and Africa, but the flu didn't travel with them."

Therefore, the number of cases of the bird-transported disease -- H5N1 -- fell off steeply when flocks arrived in Europe in April and May. This is a reversal compared with just a few months ago. In February dozens of cases were detected.

"An explanation for this might be that infected birds die quickly," said a statement from the wetlands organization, which is based in the Netherlands. That's only a guess, and in fact, officials on both sides of the Atlantic aren't quite sure what to make of the surprising news.

So far, all they have been able to do is monitor the numbers.

In thousands of samples collected in Africa this winter, not one case of bird flu was detected in wild birds. In Europe only a couple of cases have been found since April, which is the height of the northward migration period.

Now officials believe that the northern migration of the birds played no role. The last case of the deadly bird flu virus discovered in a wild bird in Europe was found in one grebe on April 28 in Denmark. Earlier, other cases were found in a few swans in France and a falcon in Germany.

Robert Webster, a virologist at St. Jude Children's Research Hospital in Memphis, Tenn., who discovered the virus, told ABC News all this is "really most encouraging."

Webster said he believed that while it was still possible for the virus to show up in migratory birds on U.S. shores this spring, he believed it was unlikely. He points out that historically there is little crossover of flu viruses between American and European migratory birds. He said there is more good news ahead, too.