Researchers have said that a strain of an airborne fungus that has caused several deaths in Oregon appears to be moving toward California.

The mortality rate for Cryptococcus gattii fungi in the Pacific Northwest is approximately 25 percent out of 21 cases analyzed, Edmond Byrnes III, a graduate student at the Duke University Medical Center, said.

Byrnes said in a statement, "This novel fungus is worrisome because it appears to be a threat to otherwise healthy people. Typically, we see this fungal disease associated with transplant recipients and HIV-infected patients, but that is not what we are seeing."

Most of the people affected have a more complicated clinical course than people infected with the more common Cryptococcus neo-formans, Byrnes and co-authors who work in the laboratory of senior author Dr. Joseph Heitman, said.

The symptoms can appear two to several months after exposure to the fungus and may include a cough, sharp chest pain, shortness of breath, headache, fever, nighttime sweats and weight loss, the researchers further added.

Byrnes also said that C. gattii can be treated, but it cannot be prevented and there is no vaccine. (With Inputs from Agencies)