More West Nile cases reported The Department of Health reported 82 more human West Nile cases Sept. 23, bringing the total number of reported cases to 892. There have been eight deaths reported.
Lake County reported its first two human cases of West Nile illness. Every county in the state but Deuel County has now reported human West Nile cases. Counties with the highest number of cases include Pennington (112), Brown (74), Hughes (40), Minnehaha (38), Butte (31), Lawrence (25), Charles Mix (21), Meade (21), Dewey (20), Fall River (20), Davison (18), Marshall (18), Shannon (17), Turner (16), Beadle (15) and Brookings (15). The eight deaths occurred in Brown, Clay, Meade, Pennington (3), Shannon and Ziebach Counties.
Of South Dakota's cases, 121 have been reported with meningitis, encephalitis or meningoencephalitis; 585 with West Nile fever; and four with acute flaccid paralysis syndrome associated with WNV infection. Many cases are still under investigation or have a pending diagnosis.
Fifty-two percent of the cases are male and 48 percent are female. Eighty-seven percent of the cases are white and 12 percent are Native American.
The median age is 44 years and the ages range from less than 1 month to 96 years.
The elderly are at greatest risk of meningoencephalitis, the most severe form of WNV disease; 55 percent of the cases are over 50. The median age of the deaths is 79 years (range 34 � 89). The deaths are 75 percent male and 25 percent female.
Nearly all human West Nile infections are from mosquito bites; however there has been West Nile virus transmission associated with blood transfusions. The implementation of national blood donor screening in July 2003 has reduced this risk by removing units of potentially infectious blood.
There have been 56 asymptomatic individuals detected through routine screening of blood donations since July in South Dakota.
Veterinary West Nile positives have included 122 birds, 72 ill horses, two dogs and two squirrels.
The West Nile transmission season will continue until an area experiences its first hard frost, which is a temperature of 28 degrees Fahrenheit or less. People are encouraged to take anti-mosquito precautions until the first hard frost hits their area.
For more information please go to the South Dakota West Nile Virus Web site www.state.sd.us/doh/westnile.