Image courtesy Edmond Byrnes and Joseph Heitman, Duke Dept. of Molecular Genetics and Microbiology
Updated May 2, 2010
A new strain of hypervirulent, deadly Cryptococcus gattii fungus has been discovered in the United States, a new study says.
The new strain is of the species Cryptococcus gattii, an airborne fungus native to tropical and subtropical regions, including Papua New Guinea, Australia, and parts of South America. An older strain of the fungus was frst detected in North America in British Columbia, Canada, in 1999.
No one knows how the species got to North America or how the fungus can thrive in a temperate region, experts say.
"The alarming thing is that it's occurring in this region, it's affecting healthy people, and geographically it's been expanding," said study co-author Edmond Byrnes, a graduate student at the Joseph Heitman Lab at Duke University.
Less common than bacterial and viral infections, fungal diseases usually strike people with weakened immune systems—part of what makes the recent deaths of otherwise healthy people in Oregon so worrisome.
People can become infected with Cryptococcus gattii by inhaling the microscopic organisms—and there's not much you can do about it.
There's no vaccination or other preventative measure available for the new strain, though the infection can be treated with antifungals, the study says. And "there are no particular precautions that can be taken to avoid Cryptococcosis," according to the British Columbia Centre for Disease Control. "You can, however, be alert for long lasting or severe symptoms and consult a physician (or veterinarian for animals) for early diagnosis and treatment."
Appearing several months after exposure to the fungus, the infection causes a bad cough and shortness of breath, among other symptoms.
On a positive note, fungal infections, unlike viruses, can't be passed from person to person.
Fast-Spreading Cryptococcus Gattii Superfungi
The first U.S. Cryptococcus gattii cases were identified in 2005. It wasn't until the new study, though, that genetic analysis revealed that the fungus is a new strain that had originated in Oregon.
Of the 21 known cases involving the new strain, 6 have been fatal—about 25 percent. The new strain has so far been deadlier than the strain in British Columbia, which killed 19 out of 218 known victims, or 8.7 percent.
The organism has also attacked domestic and wild animals, according to the study, published April 22 in the journal PLoS Pathogens.
Though the reason for the new strain's severity is unknown, "one thing fungi do that bacteria don't is they have sex with each other," Byrnes noted. (Related: "Rainmaking Bacteria Ride Clouds to 'Colonize' Earth?")
As with humans, nearly every fungus offspring represents a new combination of genes and their resulting traits. So it's possible that the new fast-spreading superfungi is the result of Cryptococcus gattii mating. (Learn more about human diseases.)
My cat has criptocaucous and is starting treatment tomorrow. This thing is alive and well in rainy cold Washington State. Pray for her.
People really need to pay attention to this article. I ask you this how do you know we dont spread the spores by breathing them out? How do we know that this fungus might just be the root problems to all these mass reoccurring infections seen worldwide? Considering it leaves little lesions inside the body in which abcess would occur, causing staff in which the antibiotics kill but yet MRSA reoccurs why because the ROOT problem is this fungus for godsake someone needs to stand back and look at the bigger picture here look around at all the people you know how many are constantly sick dry skin fatigued look as if they aged a decade in just the last year,
@rhonda prideaux How much will the treatment cost and how long does it take? I'm pretty sure the kitten I get from Burlington has this, I'm just waiting on the results.
@Kali Austin WTF are you talking about? did you pay attention while reading the article?
Feed the World
How do we feed nine billion people by 2050, and how do we do so sustainably?
We've made our magazine's best stories about the future of food available in a free iPad app.
Latest From Nat Geo
These cooing Casanovas use showstopping plumage to court females and fend off rivals.
Meet a trapper who keeps Florida's streets, sewers, and Kennedy Space Center alligator free.