Published: Jul 01, 2011 6:29 PM EDT
Updated: Jul 01, 2011 5:29 PM EDT

LINCOLN, Neb. (AP) - Mosquito pools in three Nebraska counties have tested positive for West Nile virus.

The state Department of Health and Human Services says the positive results came from recent tests done in Madison, Dawson, and Douglas counties.

Nebraska's chief medical officer, Joann Schaefer, says it's still early in the season so the virus will likely surface elsewhere in the state. She urges people to take precautions, such as wearing mosquito repellent and wearing long-sleeved shirts and pants outside when mosquitoes are active.

West Nile virus is transmitted to humans through the bite of a mosquito that has picked up the virus by feeding on an infected bird. Last year in Nebraska, there were 48 confirmed human cases and two deaths from West Nile.

(Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)