1st Mystery Virus Case Suspected in California : Health: Fatal symptoms suffered by UC graduate student fit definition of disease, officials say. Precautions are advised for those who live where deer mice roam.

A UC San Diego graduate student who worked and lived in a nature reserve here may have died as a result of a mystery flu-like illness suspected of killing 29 people in the Four Corners area of the desert Southwest, authorities said Saturday.

State and federal medical experts began arriving Saturday in Mammoth Lakes in the Eastern Sierra to investigate whether Jeanne Messier, 27, was the first California case of the deadly disease.

The U.S. Centers for Disease Control and Prevention recently linked the illness, discovered among Navajos in the Four Corners region, to a hantavirus carried by deer mice and spread when their urine and feces dry and become airborne.

Messier, who was studying ornithology, died suddenly of lung failure Friday after being rushed to a hospital in Reno. Nevada state health officer Don Kwalick said Messier’s illness and sudden death met the CDC’s definition for infection with the hantavirus.

Nevada public health adviser Dave Nelson said he was told that the victim had lived in a house infested by rodents.

Researchers from the CDC and the California Department of Health Services plan to take blood samples from Mammoth area residents, health services spokeswoman Betsy Hite said. Health authorities plan to hold a news conference today in Mammoth Lakes, a resort town about 200 miles north of Los Angeles.

In the meantime, blood drawn from the woman’s body was sent to a laboratory for testing. Results may be known by Monday, said Dr. Richard Jackson of the state health department.

Messier lived and worked at the Valentine Ecological Reserve in the heavily forested Old Mammoth area. The reserve is owned by the University of California and operated by UC Santa Barbara.

A physician who treated Messier cautioned people living in the Mammoth Lakes area to remain calm.

“This hasn’t been confirmed yet,” Dr. Steven Parker told Associated Press. “I would hate for people to sell their homes in the mountains and rush to the beaches without final word on what this is.”

To date, the Four Corners illness, officially called hantavirus-associated respiratory distress syndrome, or HARDS, is believed to have killed 29 of 49 people infected. The presence of the virus has been confirmed in 21 patients, 15 of whom have died.

While nearly all of those infected have come from the Four Corners area of Arizona, Colorado, New Mexico and Utah, the illness has spread outside the region, the CDC reported last week. Cases were found in Texas and Nevada.

Deer mice are hosts for the hantavirus but do not suffer any ill effects. California has a large population of deer mice that grew larger this spring after the winter’s heavy rains and snow.

Officials advise people who live in areas with deer mice to seal all openings by which the rodents can enter homes, keep garbage in rodent-proof containers and set rodent traps in woodpiles.

Times staff writer Freed reported from Los Angeles; special correspondent Forstenzer from Mammoth Lakes. Associated Press also contributed.