DALLAS (AP) -- A Texas county is experiencing the nation's deadliest outbreak of West Nile virus this year and a public health emergency has been declared.
Dallas County officials have authorized aerial spraying of insecticide for the first time in nearly five decades to help fight the mosquito-borne illness.
The state's second most populous county announced the decision on Friday after its leaders met with the state's top health official and experts from the Centers for Disease Control and Prevention. Nearly 90 cases of the most severe form of West Nile have been confirmed in the county so far, nine residents have died, and the virus' peak season is just beginning.
Judge Clay Jenkins, the county's top elected official, calls it "a matter of extreme concern."
Five planes have been requested for spraying the heavily populated northern part of Dallas as well as the nearby enclaves of Highland Park and University Park if leaders in those areas approve.
There is no vaccine for the virus, which most often affects people over 50. It can cause high fevers, headaches and disorientation.