Epidemiological and phylogenetic characterization of Newcastle disease viruses isolated from exotic, wild and commercial birds in Mexico between 2008 and 2011

Newcastle disease (ND) is one of the most important health problems that affect the poultry industry around the world and it is caused by Newcastle disease virus (NDV). NDV is considered to be endemic in several countries including Mexico and in order to control ND outbreaks and spread, intensive vaccination programs have been established, which include vaccines strains isolated at least 60 years ago, which unmatched the genotype group of the viruses that circulate in the country. Here, several isolates obtained from different regions of Mexico and from wild, exotic birds and poultry, were analyzed in order to study the recent epidemiology of ND in Mexico. The characterization and phylogenetic studies confirm that virulent NDV from genotype V continues circulating and evolving. All the lentogenic isolates, mostly isolated from wild and exotic birds were highly related to LaSota and Vitapest L vaccine strains. These findings suggested that vaccine viruses may be escaping from poultry and also, that wild birds may be playing a role in the spreading.