A West Nile virus gene study, by scientists from UTMB and Harris County, appears in Emerging Infectious Diseases. They based their analysis of WNV evolution using a surveillance system that was first put in place in the Houston area in 1964 to address the St. Louis encephalitis virus. The group also said that the Houston area is a good location for exploring the virus, because the southeastern coastal region of the state is a temporary roosting site on a major flyway for migratory birds, and the area hosts more avian species, and possibly more WNV reservoir hosts, than anywhere else in the United States. Their analysis included gene sequencing that explored viral evolution by looking at nucleotide changes, amino acid substitutions, and conducting phylogenetic and geospatial studies.