Possible H5N1 bird flu in Rotterdam zoo

The disease was discovered at the Diergaarde Blijdorp zoo during a routine check. The zoo's initial suspicion was confirmed by the CIDC-laboratory in Lelystad. A follow-up test will establish whether or not the virus is actually the H5N1 strain of bird flu.

The four hawk owls that died had not been vaccinated, because they hatched in May, which was after the last vaccination round for bird flu in zoos.

The first animal became sick on July 27, with another two birds becoming sick on July 30 and August 7, dying on August 9. On August 10 the fourth hawk owl became sick. All animals have been removed from the zoo.

Visitors to the zoo are not in danger and the zoo remains open. All birds that are not immunised will receive a vaccination or will be kept inside. The aviary of the hawk owls has been screened.

How the hawk owls became infected is not yet clear and is under investigation.

Two weeks ago a mild H7 strain of bird flu was diagnosed at a farm in Voorthuizen. Several countries banned poultry imports from the Netherlands as a consequence.