West Nile in 15 S.D. counties The South Dakota Department of Health reported three new human WNV disease cases July 30 in residents of Codington and Minnehaha (two) counties. This brings the number to 10 human WNV cases and two blood donor detections in South Dakota during the 2004 WNV transmission season. West Nile has been detected in 15 South Dakota counties.
Fourteen percent of cases have been diagnosed with neuroinvasive disease and 86 percent with WNV fever. Sixty percent of cases are female and 40 percent male. The median age of cases is 43 years with an age range from 9 to 88 years. The elderly are at greatest risk of the most severe form of WNV disease and complications; 40 percent of cases are over 50 years old.
Also reported July 30 were three positive birds from Beadle (crow), Marshall (blue jay) and Davison (crow) counties. A testing summary follows:
* Humans: 10 cases (Aurora, Beadle, Charles Mix, Codington, Davison, Jackson, McCook, Minnehaha two, and Pennington counties). Two positive blood donors (Hand, Minnehaha)
* Birds: 90 negative, 12 positive (Beadle one; Brookings two; Brown one; Clark one; Davison one; Hughes two; Marshall one; Minnehaha two; and Pennington one). Positive bird detections include five blue jays, five crows, one Swainson's hawk and one kestrel.
* Horses: three positive (Brookings, Charles Mix and Pennington).
* Mosquitoes: 14,181 mosquitoes tested, 150 positive Culex tarsalis (Brookings and Minnehaha counties); 50 positive Culex pipiens (Minnehaha County).
* Sentinel chickens: 213 tested, all negative (Brookings and Hughes counties).
These human WNV cases, along with bird, horse and mosquito detections, indicate that the virus is widespread in South Dakota and everyone should take precautions to avoid mosquito bites. All South Dakotans and visitors should be protecting themselves from mosquitoes. South Dakotans are encouraged to reduce their risk of West Nile by taking precautions to avoid mosquito bites.
* Use a mosquito repellent containing DEET when outdoors.
* Screen all windows and doors and keep screens in good repair.
* Wear shoes, socks, long pants and a long-sleeved shirt to limit mosquito exposure.
* Limit time outdoors at dusk and dawn when mosquitoes are most active.
* Eliminate standing water that gives mosquitoes a place to breed.
* The elderly and pregnant women should be especially mindful to take precautions.
For more information about West Nile visit the Depart-ment 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.