PIERRE -- As human West Nile virus cases continue to rise, a state health official urges South Dakotans to use mosquito repellent and take other precautions to protect themselves.

"South Dakota has the highest number of human West Nile cases in the nation, as well as the highest number of the more serious neuroinvasive cases," said Lon Kightlinger, state epidemiologist for the Department of Health.

"Neuroinvasive disease can be particularly serious for the elderly and those with health conditions such as cancer, diabetes and high blood pressure, or a history of alcohol abuse."

As of Aug. 6, South Dakota had reported 21 human West Nile cases, followed by California with 18. Ten of South Dakota's cases were neuroinvasive, while the next highest were Minnesota and Mississippi with eight cases each.

Kightlinger said South Dakota has also reported 172 WNV-positive mosquito pools.

"Clearly, the virus is circulating in our state, so people need to get in the habit of remembering repellent for all their outdoor activities, especially now that school is approaching with its fall sports season," said Kightlinger. "Parents and coaches need to make sure their athletes use repellent for those outdoors practices and events."

To prevent mosquito bites and reduce the risk of WNV:

• Use mosquito repellents (DEET, picaridin, oil of lemon eucalyptus, or IR3535) and limit exposure by wearing pants and long sleeves in the evening.

• Limit time outdoors from dusk to midnight when Culex mosquitoes are most active.

• Get rid of standing water that gives mosquitoes a place to breed.

• Support local mosquito control efforts.

Find WNV prevention information on the Web at http://westnile.sd.gov.