Some of the tests require two blood samples taken about two weeks apart. Treatment is supportive, dealing with problems caused by the virus in the brain. Antibiotics are not effective because the infectious agent is a virus. There are no vaccines approved for humans in the United States. There are vaccines available for use in horses.
Mosquitoes breed in standing water.
Change the water in birdbaths at least once a week. Clean and chlorinate swimming pools or drain and cover if not in use. Unclog gutters and downspouts. Make sure that doors and windows have tight-fitting screens. Do not use DEET on infants.