Bill Ballou, CA---Molly Duke, CA

Sacramento and San Joaquin counties.

Bill Ballou got sick in late July, suffering from nausea and a fever that got worse, despite three visits to three different doctors. He said that not one of the doctors mentioned West Nile virus.

Finally, Ballou demanded to be tested for the virus. His test came back positive, and now he is recovering.

"I think it would have helped all of us to know earlier because they did two different batteries of tests, all of which were unnecessary," Ballou said.

Molly Duke, of Fair Oaks, said she had to push her doctor to even consider West Nile virus. And when she was finally tested she too came back positive for West Nile virus.

"It frustrated me when I went in to get the blood test. I felt they didn't take me seriously," Duke said.

An expert with Kaiser Permanente, Dr. Dave Herbert, told KCRA 3 that West Nile virus is difficult to diagnose, adding that a patient can have the virus without testing positive. He said that the blood test only works after the virus has incubated, producing anti-bodies in the patient.

Kaiser officials said that they understand the frustration of patients, who want to immediately know what is wrong with them. They added that seven out of every 10 people who are being tested for the virus are coming up negative.