Canine distemper virus diversity in Lake Baikal seal (Phoca sibirica) population

Morbillivirus epizootics in marine mammals have been found in a variety of marine mammal species throughout the world over the past 20 years. The virus epizootic which resulted in significant mortality of Siberian seals (Phoca sibirica) in Lake Baikal during 1987–1988 was caused by the canine distemper virus (CDV). In our previous papers we provided evidence that the CDV similar to strain, identified in 1988, continued to circulate in Lake Baikal seals after 1988. The aim of this study was an up to date detection of CDV in Baikal seals and an evaluation of the genetic diversity of Baikal seal CDVs in comparison with other virus isolates and strains available in the GenBank on the basis of nucleotide sequence analysis of the phosphoprotein gene fragment. The majority of CDVs recovered from 1992 till 2007 were found to be similar to the one responsible for the epizootic of Lake Baikal seals. Phylogenetic analysis revealed that more than one genotype of CDV was circulating in Lake Baikal seals after the epizootic of 1987–1988.