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.
When the rare threats "take shape in the news, a viewer may perceive a lack of control ...and may thus develop a sense of heightened anxiety or vigilance [about it]," said Kim Liebowitz, director of cardiac behavioral medicine at Bluhm Cardiovascular Institute of Northwestern Memorial Hospital in Chicago.
Vanderbilt's Schaffner said, "If something new pops ups -- if it's novel, mysterious, and if it can strike seemingly anyone, anytime, you suddenly feel like you have no control over the situation. If the threat is disfiguring or life-threatening, if there's no preventative measures you can take against it, these elements invoke fear."
This reaction is known as behavioral conditioning, Liebowitz said, and it means that one can develop strong negative reactions to a threat just by hearing about victims and identifying with them;- no personal experience with the risk required.
At the end of the day, the actual threat the bizarre afflictions pose for any individual is quite small, so it's better to nip needless anxiety in the bud, doctors say.
One way is to see this threat in perspective, said Dr. Robert Betts, infectious disease expert at the University of Rochester in New York.
While 21 cases of C. gattii infection have been documented to date, "hundreds or even thousands have been infected with this fungi, but only a few become ill," he said.
In other words, it's not as though anyone who walks past this spore is doomed to infection.
Also, looking at these rare risks in comparison to the none-too-rare risks we face every day can help highlight one's tendency to be overly anxious about such things, Lebowitz said.
The common fear of flying is a good example of how we misjudge danger.
"So many individuals have a fear of flying despite very safe aviation records," but these same individuals do not fear driving, "which is more dangerous," she said.
It's not the safety records or level of risk people pay attention to, she added, it's the "emotionally laden content" of the stories told about victims of the rare dangers.
As far as the fear of fatal fungi, Alcabes of Hunter College pointed out that the strain is likely to fade out soon.
"In most cases, when new strains arise, they are transient," he says.
Certainly, he said, "it's worth asking, 'Is there some new risk here?'"
But in this particular case, he said, "I see no new threat at all, just a slightly different name for an existing, and rather rare, danger."