NEWCASTLE-DISEASE OUTBREAKS IN RECENT YEARS IN WESTERN-EUROPE WERE CAUSED BY AN OLD (VI) AND A NOVEL GENOTYPE (VII)

Newcastle disease virus (NDV) strains, isolated from outbreaks during epizootics between 1992 and 1996 in Western European countries, were c ompared by restriction enzyme cleavage site mapping of the fusion (F) protein gene between nucleotides 334 and 1682 and by sequence analysis between nucleotides 47 and 435. Both methods revealed that NDV strain s responsible for these epizootics belong to two distinct genotypes. S trains derived from sporadic cases in Denmark, Sweden, Switzerland and Austria were classified into genotype VI [6], the same group which ca used outbreaks in the Middle East and Greece in the late 1960's and in Hungary in the early 1980's. In contrast, viruses that caused epizoot ics in Germany, Belgium, The Netherlands, Spain and Italy could be cla ssified into a novel genotype (provisionally termed VII), hitherto und etected in Europe. It is possible that the genotype VII viruses origin ated in the Far East because they showed a high genetic similarity (97 %) to NDV strains isolated from Indonesia in the late 1980's.