The World Organization for Animal Health announced today, Tuesday, that Croatia has detected an outbreak of the highly infectious "H5N5" strain of the avian influenza virus at a poultry farm. The Paris-based organization reported, citing Croatian authorities, that the outbreak has resulted in the infection of five domestic birds out of a flock of 19,600 in a farm located in the Brodsko-Posavska region near the border with Bosnia. Highly infectious avian influenza has spread globally in recent years, leading to the culling of an estimated hundreds of millions of domestic birds.