Officials Plan No Quarantine for Hantavirus : Health: Authorities believe fatal infection of graduate student is an isolated incident. But they warn people in Mammoth area to stay away from rodents, which carry the disease.

MAMMOTH LAKES —  Describing the death of a UC San Diego graduate student from a mysterious flu-like illness as an isolated incident, health officials said Tuesday that no travel restrictions or quarantines will be placed on this resort area.

Jeanne Messier, 27, died Friday after being infected with the hantavirus while working and living in the Mammoth area. The hantavirus is responsible for at least 17 deaths, mostly among American Indians, in the Four Corners area of the Southwest.

Local and federal authorities who are studying the deadly virus, which is spread through the droppings of deer mice, warned visitors to the Eastern Sierra vacation spot to stay away from rodents and exercise care in cleaning up after them.

“We’re at the peak of the small-rodent cycle,” Dr. Jack Bertman, Mono County health officer, said at a news conference. “Many, many are running around in the woods and structures, but there is no evidence at this point that we are on the verge of an epidemic problem.”

Bertman compared the hantavirus incident to other risks that can befall urban dwellers who venture into the wilds for fun and adventure, such as Lyme disease from ticks, forest fires and bubonic plague, which is transmitted to humans by fleas.

Mono County health officials recently closed several campgrounds in the area because of plague outbreaks. One reason, Bertman said in an interview, is that researchers know much more about the plague, which occurs in several areas of California, than they do about hantavirus.

State epidemiologists have created risk policies to deal with the plague, and they conduct regular inspections of campgrounds looking for infected rats and large numbers of fleas. When enough plague and fleas are found, campgrounds are closed until health officials can spray for fleas.

In essence, health officials said, they know what to do with the plague but not with the virus that killed Messier less than two days after she came to Centinela Mammoth Hospital complaining of achiness, weakness and fatigue.

Hantavirus “is something we don’t know much about at all,” Bertman said. “If I had more indications that this was anything more than a sporadic incident, we’d certainly be considering what recommendations we should make for closure. There’s no scientific reason for a closure.”

That pleased Mammoth-area tourism officials, who note that August is among the busiest months of the summer vacation season.

Ralph McMullen, director of the Mammoth Lakes Visitors Bureau, said that many vacationers and their hotels have been inquiring about the virus but that business is normal.

“Obviously no one wants a quarantine,” McMullen said in an interview. “From our standpoint, we’re glad about the news.”

Nonetheless, the investigation into Messier’s death continues. Dr. Jordan Tappero, a epidemiologist with the U.S. Centers for Disease Control and Prevention in Atlanta, said at the news conference that investigators have drawn blood from about 30 of Messier’s colleagues to see if any show signs of the virus.

In addition, health officials will begin trapping mice in the area later this week to test for signs of the disease. When the results of both sets of tests are completed, officials will decide whether more widespread blood testing and travel restrictions are necessary, Bertman said.

A local 52-year-old man also died of respiratory illness over the weekend. Although Bertman said his death is probably not caused by the hantavirus, tissue samples have been sent to the Centers for Disease Control for study.

Daniel Dawson, manager of the Valentine Ecological Reserve, where Messier was doing field research, said that the young woman was buried Tuesday at an undisclosed East Coast location. A scholarship fund has been set up in her memory at the UC San Diego department of biology.