As West Nile Virus Cases Rise, Vaccine Still Far Off

Monitor Patients at Higher Risk

She noted that until a treatment or vaccine for humans does become available, clinicians should pay close attention to patients at higher risk.

"I think it's important that clinicians are aware of those people who may be at risk of developing more severe disease, such as those with conditions including diabetes, cancer, hypertension, and kidney disease," Dr. Hills said.

"Being particularly aware of those people and following them closely is probably the most important message."

The symptoms of severe West Nile illness to be aware of in such patients can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis, according to the CDC.

Symptoms of milder cases of West Nile fever include fever, headache and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach, and back. The symptoms can be present for just a few days to several weeks.

Dr. Hills and Dr. Schaffner have disclosed no relevant financial relationships. Dr. Dayan is an employee of Sanofi-Pasteur. Dr. Diamond consults for MacroGenics, and Washington University has licensed a monoclonal antibody that his team has developed for possible commercialization by the company.