South Dakota reports 5 human West Nile cases The South Dakota Department of Health reported five new human West Nile cases Sept. 3. The new cases are residents of Butte, Hughes, Meade, Pennington and Tripp counties. There have now been 30 WNV disease cases and three blood donor detections reported in South Dakota during the 2004 transmission season. Also reported Sept. 3 are a WNV positive horse from Minnehaha County and a positive blue jay from Hamlin County. West Nile has been detected in 31 South Dakota counties to date.
Seventeen percent of human cases have been diagnosed with neuroinvasive disease and 83 percent with WNV fever. Sixty-seven percent of cases are male and 33 percent female. Eighty-nine percent of cases are white, 7 percent Native American and 4 percent other races. The median age of cases is 41 years with an age range from 9 to 77 years. The elderly are at greatest risk of the most severe form of wnv disease and complications.
"The West Nile virus is circulating in South Dakota," said Dr. Lon Kightlinger, state epidemiologist. "People should use mosquito repellent, wear pants and long sleeves while they are camping, fishing, hiking and picnicking.
A testing summary follows:
* Humans: 30 cases (Brown four, Minnehaha three, Pennington three, Beadle two, Butte two, Charles Mix two, Meade two, Aurora, Codington, Davison, Dewey, Jackson, Hughes, Lake, McCook, Moody, Roberts, Spink and Tripp counties) and three positive blood donors (Hand, Minnehaha, Tripp). The S.D. Public Health laboratory has tested 2,254 human blood or spinal fluid specimens for the West Nile virus this year.
* Birds: 69 positive (Day 45, Marshall three, Brookings two, Brown two, Hamlin two, Hughes two, Minnehaha two, Pennington two, Beadle, Clark, Charles Mix, Davison, Grant, Kingsbury, Lincoln, Potter and Yankton). Positive bird detections include 45 pelicans, 14 blue jays, five crows, two red-tail hawks, one kestrel, one mourning dove, and one Swainson's hawk. One hundred eight have tested negative at the S.D. Public Health Laboratory.
* Veterinary: four positive horses (Brookings, Charles Mix, Minnehaha and Pennington), and one positive dog (Turner).
* Mosquitoes: 647 positive Culex tarsalis (encephalitis mosquito), 150 positive Culex pipiens (northern house mosquito) and 32 Aedes vexans (floodwater mosquito) in Beadle, Brookings, Minnehaha and Pennington counties. 36,475 mosquitoes have been tested at the S.D. Public Health Laboratory.
* Sentinel chickens: one positive sentinel chicken (Hughes County). 231 tested negative.
Nationally, as of Aug. 31, 47 states had reported West Nile activity to the Centers for Disease Control and Prevention, including 1,053 human cases in 35 state.
This compares to 1,856 cases in 36 states at this time last year. Twenty-eight deaths have been reported nationally this year. Arizona and California have reported 64 percent of the nation's cases.
Eighty-five WNV positive blood donors have been reported nationally in 2004, including three from South Dakota. In addition, 407 horses, 3,978 birds and 571 sentinel chickens have been reported nationally with West Nile virus.