FRANKNOTE

Infections from a new strain are unpreventable - and the strain is spreading.

A new strain of hypervirulent, deadly Cryptococcus gattii fungus has been discovered in the United States, a new study says.

The outbreak has already killed six people in Oregon, and it will likely creep into northern California and possibly farther, experts say.

The new strain is of the species Cryptococcus gattii, an airborne fungus native to tropical and subtropical regions, including Papua New Guinea, Australia, and parts of South America. An older strain of the fungus was frst detected in North America in British Columbia, Canada, in 1999.

No one knows how the species got to North America or how the fungus can thrive in a temperate region, experts say.

"The alarming thing is that it's occurring in this region, it's affecting healthy people, and geographically it's been expanding," said study co-author Edmond Byrnes, a graduate student at the Joseph Heitman Lab at Duke University.