West Nile virus has been confirmed in Rock County. No human cases yet, but Rock County Health Officer Karen Cain says a dead crow found between Janesville and Milton was infected. Cain says the virus is carried by mosquitoes and recommends taking precautions. She advises using mosquito repellent, covering exposed skin with clothing, eliminate standing water, trim tall grass and weeds, and ensure house screens have no holes. Four-out-of-five people infected will likely never know it, but for some it can be deadly. The most common symptoms include fever, body aches, rash, and fatigue. On the bright side, if you are ever infected, you will become immune.