Jul 14, 2005 (CIDRAP News) The annual invasion of West Nile virus has sickened 25 people in 11 states and caused one death so far this summer, the Centers for Disease Control and Prevention (CDC) said today.
Colorado leads the list with 7 cases, followed by South Dakota with 5 and Arizona with 3, according to an article in Morbidity and Mortality Weekly Report. The single death occurred in Missouri.
Other states that have reported cases to the CDC are California, Georgia, Indiana, Kansas, New Mexico, Ohio, and Texas. This year's first case was reported in Kansas in May.
Nine of the 25 cases were the severe, neuroinvasive form of West Nile, the CDC said. Another 15 cases were listed as West Nile fever, and one case was unspecified.
West Nile virus is spread to humans by mosquitoes that have fed on infected birds, which are believed to be the main reservoir for the virus. The CDC says that infected crows and other birds have been found in 16 states so far this season.
About 20% of people infected with West Nile get sick, and about 1 in 150 suffers the severe form, West Nile meningitis or encephalitis. Roughly 17,000 Americans have had the disease since it made its North American debut in 1999. Last year the United States had 2,539 cases with 100 deaths, according to the CDC.
CDC. West Nile virus activityUnited States, 2005. MMWR 2005 Jul 15;54(27):678-9 [Full text]
CDC's West Nile virus site