THURSDAY, Oct. 18, 2012 (MedPage Today) — The CDC has received reports of 4,531 cases of West Nile virus infection, the second highest total since the virus emerged in the U.S. in 1999 — but this year marks a new high in reports of severe disease.
There were 4,269 cases seen in 2006. The highest total remains the 9,862 reported in 2003, although the CDC has called that number an artifact of excessive testing by one state that year.
This year, roughly half of this year’s cases — 2,293 — involved neuroinvasive disease. The highest numbers of severe disease seen previously were 2,946 in 2002 and 2,866 in 2003.
Also this year, the virus has been associated with 183 deaths, the third highest total. The outbreaks in 2002 and 2003 claimed more (284 and 264, respectively).
Nearly 70 percent of the cases from the current outbreak were reported by eight states — Texas, California, Louisiana, Mississippi, Illinois, South Dakota, Michigan, and Oklahoma. Texas has been the hardest hit, accounting for more than one-third of the cases.