EXPERIMENTAL-INFECTION OF VACCINATED SLAUGHTER OSTRICHES WITH VIRULENT NEWCASTLE-DISEASE VIRUS

A virulent Newcastle disease virus (NDV) isolate from an outbreak in c ommercial poultry, with virulence indices of MDT = 47-48 h; IVPI = 2,1 7 and ICPI = 1,8, was used to inoculate 10x vaccinated (standard poult ry vaccines) as well as 10x unvaccinated slaughter ostriches via intra tracheal, ocular and nasal routes, in a controlled environment. All un vaccinated ostriches developed clinical signs (mainly respiratory); tw o of them died while the other eight recovered. No vaccinated ostriche s developed any clinical signs. All remaining (18) ostriches were slau ghtered 14 d after the last mortality. Virulent NDV could be re-isolat ed from the dead birds, but not from organs, muscle (fresh), muscle (2 4 h chilled), gastro-instestinal tract, bone-marrow or respiratory sys tem taken from the slaughtered ostriches. It is suggested that it woul d be extremely unlikely that the international trade in ostrich meat c ould act as a mechanism for spreading virulent NDV from endemic to non -endemic parts of the world.