This year has certainly been a serious year for West Nile Virus: The mosquito-borne disease has spread to all of the lower 48 states except for Maine. Across the nation, a total of 4,249 cases and 168 deaths have been reported to date. In Texas alone, there were 1,520 cases and 54 deaths. These numbers are unusually high; last year, the US had only 712 cases total. So why the sudden uptick in West Nile?