It sounds like a plot straight out of a science fiction movie: A new strain of a deadly airborne fungus in Oregon is set to spread to California.
But there's no need to sound the alarm, doctors say.
The new strain of the well-known Cryptococcus gattii fungus is "worrisome" because it appears to be a threat to otherwise healthy people, according to a report released today by Duke University Medical Center.
The fungus had previously affected only people with weakened immune systems.
It is absorbed through the lungs and the symptoms of infection, which can appear two to several months after exposure, can include chest pain, shortness of breath, headache, fever and a cough lasting weeks, according to researchers.
Scientists at Duke have called for awareness and vigilance regarding the potentially harmful fungus, but doctors caution that while increased research may be wise, the new strain should not be of concern to the public.
To make a big deal out of this would be "a great example of the manufacturing of risk," said Philip Alcabes, a professor of urban public health at Hunter College School of Health Sciences in New York City.
One would be as likely to be hit by lightning as to be afflicted by this strain, said Dr. William Schaffner, chair of preventive medicine at Vanderbilt University in Nashville, Tenn.
He says the new development is "more of a curiosity" than a threat, one that should only provoke interest in microbiologists and infectious disease specialists.
Despite the caveats, the report, which documents the spread of the deadlier strain and calls for increased vigilance, is poised to trigger public concern.
As with past rare scares, doctors say, the novel and unpredictable nature of the threats can prove difficult to ignore.
Periodically, a virus, or a fungus or a bacterium "will cause a lot of fuss and receive a lot of attention -- unnecessarily," Schaffner said, and then it will disappear from the public eye.
For example, a few years back a rare infectious fungus that you can get from pricking your finger on a rose thorn got some attention.
"It's usually not deadly... but it's hard to diagnose without a specialist so it can go untreated," he said, and then become painful and troublesome.
It can be alarming, he said, "because who hasn't pricked their finger on a rose thorn?"
But that is also the point of his story: Almost everybody has been pricked in their life and almost no one gets the infection, but it's scary to think that something so seemingly harmless -- and random -- could ever wreak havoc in the body.
"It has everything to do with how you perceive the risk," he said.
Other microscopic threats have created buzz in the past, especially after one kind of fungus in a pile of mulch led to the death of a British gardener in 2008.
Another scare occurred in 2002 when one boy died and another was hospitalized after contracting a rare brain infection from an amoeba while swimming in a Florida lake.
The strange and seemingly random hazards are those that are most likely to cause public panic, Schaffner said, even though they also are the least likely to actually afflict anyone.