Division 1 Preliminary differentiation

It is intended that all haemagglutinating viruses should be submitted to the national laboratory referred to in Annex II for full identification, characterization and pathogenicity tests. However, it is important that interim control measures for Newcastle disease aimed at limiting the spread of the virus should be implemented as soon as possible and regional laboratories should be able to identify the presence of Newcastle disease virus. The haemagglutinating fluids should, therefore, be used in an haemagglutination inhibition test as described in Chapters 5 and 6. Positive inhibition 1. e. 2⁴, or more, with the Newcastle disease virus specific polyclonal antiserum of titre known to be at least 2⁹ would serve as preliminary identification enabling the imposition of interim control measures.