South Dakota reports two additional probable cases of human West Nile


Article Body

SOUTH DAKOTA DEPARTMENT OF HEALTH
FOR RELEASE: August 23, 2002
CONTACTS:
Dr. Lon Kightlinger, Department of Health, 773-3737 (bird detections; human health)
Dr. Sam Holland, Animal Industry Board, 773-3321 (horse detections)

South Dakota reports two additional probable cases of human West Nile 

     PIERRE – The state Health Department today reported two additional probable cases of human West Nile. Both cases appear to be locally acquired.

     Tests at the State Public Health Laboratory identified West Nile in a 54-year-old man from Hoven, Potter County, and a 76-year-old woman from Vivian, Lyman County. South Dakota reported its first human case August 21 in a resident of Carthage in Miner County.

     The Hoven case had symptoms consistent with West Nile Fever, but no encephalitis. He was never hospitalized and has recovered. The Vivian case reported severe headache and fever. She is hospitalized in a Pierre hospital and doing well. 

     In addition to the three human detections, West Nile has now been reported in a total of 59 birds, 175 horses, and a sampling of mosquitoes from Brookings County. The virus has been detected in 48 of the state's counties.

     Positive birds have been detected in the following counties: Beadle, Brookings, Brown, Brule, Charles Mix, Codington, Davison, Day, Grant, Hamlin, Hughes, Lake, McCook, McPherson, Miner, Minnehaha, Moody, Roberts, Spink, Stanley, and Walworth.

     Counties reporting WNV positive horses include: Beadle, Bennett, Bon Homme, Brookings, Brown, Butte, Charles Mix, Clark, Clay, Codington, Day, Deuel, Davison, Douglas, Faulk, Grant, Gregory, Haakon, Hamlin, Hand, Hanson, Harding, Hughes, Jackson, Jones, Kingsbury, Lake, Lincoln, Lyman, Marshall, Meade, Minnehaha, Pennington, Perkins, Roberts, Spink, Stanley, Sully, Turner, Walworth, Yankton and Ziebach.

     West Nile is primarily a bird disease, and crows are especially susceptible. Mosquitoes become infected by feeding on an infected bird and can pass the virus to humans, horses or other hosts when they bite. Dr. Lon Kightlinger, State Epidemiologist for the Department of Health, said although most people who become infected do not become ill, the risk of human illness increases as the intensity of animal infection intensifies. Some may develop mild flu-like symptoms such as fever, headache, body aches, and occasionally swollen lymph glands or a rash. In rare cases West Nile may cause encephalitis, or inflammation of the brain. Individuals with severe or unusual headaches should seek medical care as soon as possible.

     "The last reported human cases of mosquito-borne viral encephalitis in South Dakota were in 1988 (1 case) and 1984 (2 cases) of Western Equine Encephalitis. In the 1970's there were also human cases of St Louis Encephalitis in the state. Since 1988 there have been no reported cases of mosquito-borne encephalitis in South Dakota," said Dr. Kightlinger.

     The spread of WNV across South Dakota does increase the potential risk to humans. Dr. Kightlinger emphasized that the risk of West Nile is still low but encouraged people to take precautions to protect against mosquito bites:

  • Get rid of old tires and other containers where water can accumulate and serve as a breeding ground for mosquitoes.  
  • Avoid outdoor activities at dusk and dawn when mosquitoes are most active.  
  • Wear long-sleeved shirts and long pants when in mosquito infested areas.  
  • Use mosquito repellents containing DEET, making sure to follow the directions on the container.  
  • Use bug lights and screen doors and windows.  
  • Communities in affected areas should consider adult mosquito control. On August 29, the SDSU Cooperative Extension Service will offer another session of its mosquito control training for local officials. West Nile Virus Update: Mosquito Management in South Dakota is scheduled for 1 - 5 p.m. over the Digital Dakota Network and Extension's V-tel Network. Questions should be directed to the Extension Service at 688-4596.

     South Dakota physicians are asked to be vigilant for patients who may be suffering from West Nile encephalitis. Human testing is available at the State Public Health Laboratory in Pierre. 

     Horse vaccination is recommended. Horse owners should see their veterinarians. Samples from horses suspected of infection with West Nile can be tested at SDSU's Animal Disease Research and Diagnostic Laboratory.

     More information about West Nile can be found on the Department of Health web site at www.state.sd.us/doh/WestNile/ and on the Animal Industry Board web site at www.state.sd.us/aib/