Submitted to: Preventive Veterinary Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2009
Publication Date: 3/1/2010
Citation: Perez, A.M., Pauszek, S.J., Jimenez, D., Kelley, W.N., Whedbee, Z., Rodriguez, L.L. 2010. Spatial and phylogenetic analysis of vesicular stomatitus virus overwintering in the United States. Preventive Veterinary Medicine. 93(4):258-264. Interpretive Summary: Vesicular stomatitis is an important disease of livestock caused by an insect-transmitted virus; vesicular stomatitis virus (VSV) with two serotypes: New Jersey and Indiana. From 2004 through to 2006, 751 outbreaks caused by vesicular stomatitis virus (New Jersey serotype) (VSNJV) were reported in nine Southwestern U.S. states. Outbreaks occurred during late spring and summer and it has been hypothesized that over-wintering VSNJV strains that were introduced in 2004 from endemic areas of Mexico caused the 2005 and 2006 epidemics. Our analysis indicated that clusters of cases were centered in Colorado and Wyoming, respectively. Genetic analysis of the samples provide support to our hypothesis. This information provides a useful tool for tracing VSNJV outbreaks.
Technical Abstract: From 2004 through 2006, 751 vesicular stomatitis (VS) outbreaks caused by vesicular stomatitis virus serotype New Jersey (VSNJV) were reported in nine states of the southwestern United States. The normal model of the space scan statistic and phylogenetic techniques were used to test the hypothesis that the 2005 and 2006 VSNJV outbreaks were likely to be associated to over-wintering of VSNJV in discrete regions of the southwestern United States infected in 2004 and 2005, respectively. Use of the space scan statistic led to the identification of two clusters of outbreaks for which the Euclidean distance to the nearest outbreak reported at the previous or posterior year, whichever was shorter, was significantly smaller than the epidemics mean. Clusters were centered in Colorado and Wyoming and included, respectively, 375 and 21 outbreaks. Results were supported by the phylogenetic analysis of 49 VSV samples collected from 2004 through 2006 in the United States and 10 VSV samples originated from Mexico. These findings, which were displayed using a publicly-accessible web-based system referred to as the FMD BioPortal, were compatible with over-wintering of specific sub-lineages of VSNJV in a limited geographical region of the United States affected by VS epidemics in 2005 and 2006.