Genetic Determinants of Virulence in Pathogenic Lineage 2 West Nile Virus Strains. - Botha, Elizabeth M.; Markotter, Wanda; Wolfaardt, Mariaan; Paweska, Janusz T.; Swanepoel, Robert; Palacios, Gustavio; Nel, Louis H.; Venter, Marietjie (Emerging Infectious Diseases, 2008)