Two novel genetic groups (VIIb and VIII) responsible for recent Newcastle disease outbreaks in Southern Africa, one (VIIb) of which reached Southern Europe

Citation
J. Herczeg et al., Two novel genetic groups (VIIb and VIII) responsible for recent Newcastle disease outbreaks in Southern Africa, one (VIIb) of which reached Southern Europe, ARCH VIROL, 144(11), 1999, pp. 2087-2099
Citations number
26
Categorie Soggetti
Microbiology
Journal title
ARCHIVES OF VIROLOGY
ISSN journal
03048608 → ACNP
Volume
144
Issue
11
Year of publication
1999
Pages
2087 - 2099
Database
ISI
SICI code
0304-8608(1999)144:11<2087:TNGG(A>2.0.ZU;2-7
Abstract
34 strains of Newcastle disease virus (NDV) isolated during epizootics in t he Republic of South Africa and in Mozambique between 1990 and 1995, and in Bulgaria and Turkey in 1995-1997 were identified by restriction enzyme and partial sequence analysis of the fusion (F) protein gene. The majority of isolates in southern Africa and those from Bulgaria and Turkey were placed into a novel group which has been termed VIIb. Group VIIb is part of a larg er genetic cluster (VII) that also includes NDV strains from the Far East a nd some western European countries (VIIa). The genetic distance of 7-8, 5 % between genotype VIIa and VIIb viruses excludes the existence of a direct epidemiological link between recent southern African epizootics and outbrea ks in either western Europe in the 1990's or those of the Far East. Another hitherto unrecorded genotype (VIII) was also found in South Africa with de scendants of putative ancestral members isolated in the 1960's. The genetic distance of recent group VIII strains from the major epizootic genotype (V IIb) is over 11%, therefore outbreaks caused by them were epidemiologically unrelated. Genotype VIII viruses must have been maintained in South Africa by endemic infections during the past decades while group VIIb appears to be introduced more recently.