The state Health Department reports that the number of counties where the West Nile virus has been detected so far this year has risen to 44 among the state`s 75 counties. Most recently, horses in Independence, Lee and Washington counties tested positive for the mosquito-borne disease. Fifteen people have tested positive for the virus in Arkansas so far this year. Last year, the department reported five deaths in the state among people who contracted the virus. Most people who contract the disease have mild or no symptoms. In rare cases, the illness can cause fatal brain swelling.