The death of a boy 12 years old in Cambodia and the case of a sick baby girl in Egypt showed on Wednesday the threat posed to children by the bird flu virus.
In Europe, experts called for new precautions because cats, and possibly other mammals, can be infected and could spread the virus. Dr Albert Osterhaus, of Erasmus University in Rotterdam, warned that cats may help the virus to adapt into a more highly infectious strain in humans which could spark a pandemic.
H5N1 bird flu has spread rapidly across Europe and the Middle East in recent weeks, and has flared again in Asia.
Germany said Wednesday that tests had shown a form of H5N1 had spread to domestic fowl on a large farm in the eastern state of Saxony.