To determine the cause of viral meningitis or encephalitis that occurs during the summer season; to detect the presence of West Nile Virus (WNV) and to track its spread in the community and across the United States. Viral Meningitis is inflammation of the membranes surrounding the brain and spinal cord called the meninges caused by viruses. Encephalitis is when a virus actually causes the brain to swell. For mild cases, you could have flu-like symptoms. Serious cases can cause severe headache, sudden fever, drowsiness, vomiting, confusion, and seizures. West Nile virus (WNV) is an infectious disease that first appeared in the United States in 1999. Those with symptoms may have a fever, headache, body aches, skin rash or swollen lymph glands. If West Nile virus enters the brain, however, it can be deadly. It may cause inflammation of the brain, called encephalitis, or inflammation of the tissue that surrounds the brain and spinal cord, called meningitis.