More human West Nile cases reported The South Dakota Department of Health reported four human West Nile infections Aug. 6. They included three cases of WNV disease, one in Meade County and two in Brown County, and one blood donor screening detection in a Tripp County resident. There have now been a total of 14 human WNV cases and three blood donor detections in South Dakota during the 2004 transmission season. These new cases and blood donor detections represent a 42 percent increase over the last week's numbers.
The department also reported three WNV positive birds from Marshall and Kingsbury counties, a pool of mosquitoes from Hughes County, and a positive dog from Turner County. West Nile has been detected in 21 South Dakota counties to date.
Eighteen percent of human WNV cases have been diagnosed with neuroinvasive disease and 82 percent with WNV fever. Fifty-seven percent of cases are female and 43 percent male. The median age is 42 years with an age range from 9 to 73 years. The elderly are at greatest risk of the most severe form of WNV and complications; 40 percent of cases are over 50 years old.
A testing summary follows:
* Humans: 14 cases (Aurora, Beadle two, Brown two, Charles Mix, Codington, Davison, Jackson, McCook, Minnehaha two, and Pennington Counties), three positive blood donors (Hand, Tripp, Lincoln � one blood donor report has been reclassified from Minnehaha to Lincoln County).
* Birds: 96 negative, 15 positive (Beadle one; Brookings two; Brown one; Clark one; Davison one; Day three; Hughes two; Kingsbury one; Marshall three; Minnehaha two; and Pennington one). Positive bird detections include seven blue jays, five crows, three pelicans, one red-tail hawk, one Swainson's hawk and one kestrel.
* Veterinary: three positive (Brookings, Charles Mix and Pennington Counties); one positive dog (Turner County).
* Mosquitoes: 14,281 mosquitoes tested, 250 positive Culex tarsalis (Beadle, Brookings and Minnehaha Counties); 50 positive Culex pipiens (Minnehaha County).
* Sentinel chickens: 213 tested, all negative (Brookings and Hughes counties).
The new West Nile detections indicate that the virus is being actively transmitted across South Dakota. The case in Meade County makes it clear that Sturgis Rally goers should protect themselves from mosquitoes by using repellent and wearing clothes that offer protection.
Nationally, 41 states have reported West Nile activity. As of Aug. 3, 406 human cases in 20 states had been reported to the Centers for Disease Control and Prevention, a 50 percent increase from the previous week. Arizona has the most human cases at this point in time with 247 reported cases, 61 percent of the nation's total.
South Dakotans can learn more about West Nile and how to protect themselves from mosquitoes. SDSU Extension is producing the program in cooperation with the South Dakota Department of Health and South Dakota Public Broadcasting. It will air Aug. 19, 7 p.m., on South Dakota Public Television. Viewers will be able to call in their questions during the show to have them answered on the air.
For more information about West Nile visit the Department of Health Web site at www.state.sd.us/doh/WestNile/ or call 1-800-592-1861. Information is also available from the SDSU Cooperative Extension Service at http://sdces.sdstate.edu/westnile/ and the South Dakota Animal Industry Board at www.state. sd.us/aib.