SALEM (AP) — The Oregon Department of Agriculture said the state has kept the sudden oak death disease from exploding the way it has in California.

But any chance of eradicating it from the South Coast, where it appeared in 2001, will require an expansion of the current Curry County quarantine. After hearings last year the department is increasing the quarantine from some 26 square miles to about 162 square miles based on new discoveries of the disease.

The site, northeast of Brookings, remains the only place in Oregon where the fungus causing the disease has been found in the wild.

“Our eradication efforts have worked very well at keeping sudden oak death from spreading to the rest of the state, but they haven’t eliminated the disease,” said Dan Hilburn, administrator of ODA’s Plant Division. He said it has spread slightly each year since it was discovered, and that eradication efforts continue.

The disease has left a trail of dead trees in central and northern California since it turned up in the San Francisco Bay Area in the mid-1990s. It invades trees through the bark, killing the entire tree or portions of it.

Some southwest Oregon species such as tanoak and black oak are very susceptible, but the disease also attacks madrone and myrtle trees, rhododendron, huckleberry and other shrubs.

“There is still a possibility that we can eradicate the disease. No one else in the world has ever eradicated a fungal disease like this from the wild. So the fact that we are still in the game is a remarkable achievement,” Hilburn said.

Five new diseased sites have been detected outside the original 2007 quarantine area. They are part of the original infestation, but some are more than two miles from past sites.

The quarantine has been extended to a three-mile buffer around all known infected sites. The goal is to keep potentially infected plant material from leaving the area. There are nurseries and a timber mill within the expanded quarantine area that must now meet requirements set by agricultural authorities to move products out of the area.

Research shows the disease can spread through wind-driven rain. That’s why it is important to cut down affected trees quickly to take them out of the canopy. The disease also can be found in the soil and in water.

State and federal forestry officials have been baiting more than 70 streams in southwest Oregon with rhododendron leaves as an early detection method.

The nursery industry also is worried about the disease setting up in some plants raised and shipped in Oregon.