Phylogeographic characteristics of vesicular stomatitis New Jersey viruses circulating in Mexico from 2005 to 2011 and their relationship to epidemics in the United States

•• Vesicular stomatitis New Jersey virus (VSNJV) causes most vesicular disease in the Americas.• Endemic in Southern Mexico, VSNJV causes sporadic VS outbreaks in the US at 8-10 year intervals.• We tracked the emergence and spread of a VSNJV strain from southern Mexico in 2005 into the US in 2012.• We are first to document the incursion and northward spread in Mexico, of a Central American VSNJV.• This novel VSNJV strain could threaten the US in future years.

We analyzed the phylogenetic and time-space relationships (phylodynamics) of 181 isolates of vesicular stomatitis New Jersey virus (VSNJV) causing disease in Mexico and the United States (US) from 2005 through 2012. We detail the emergence of a genetic lineage in southern Mexico causing outbreaks in central Mexico spreading into northern Mexico and eventually into the US. That emerging lineage showed higher nucleotide sequence identity (99.5%) than that observed for multiple lineages circulating concurrently in southern Mexico (96.8%). Additionally, we identified 58 isolates from Mexico that, unlike previous isolates from Mexico, grouped with northern Central America clade II viruses. This study provides the first direct evidence for the emergence and northward migration of a specific VSNJV genetic lineage from endemic areas in Mexico causing VS outbreaks in the US. In addition we document the emergence of a Central American VSNJV genetic lineage moving northward and causing outbreaks in central Mexico.