Cryptococcus gattii fungus seen in Pacific Northwest USA with 25% fatality rate among known infections

[Shiloh]

Source: http://www.cnn.com/2010/HEALTH/04/22/killer.fungus.pacific.northwest/

Killer fungus seen in Pacific Northwest
By Amanda Gardner, Health.com
April 22, 2010 5:16 p.m. EDT

(Health.com) --

snip

The fungus, known as Cryptococcus gattii (or C. gattii), has infected dozens of humans and animals--including cats, dogs, and dolphins--in Washington and Oregon in the past five years. While rare, the fungus has been lethal in about 25 percent of the people in the U.S. who have developed infections, according to Edmond Byrnes III, a doctoral student in molecular genetics and microbiology at Duke University and one of the lead authors of a new study about the fungus.


snip

Byrnes and colleagues have discovered a new, especially dangerous strain of the fungus. This strain--which is confined to Oregon, for now--is "highly virulent," says Byrnes. "Overall it's a pretty low threat, and it's still uncommon in the area, but as the range of the organism expands and the number of cases increases accordingly, it's becoming more of a concern," he says.

The new strain is likely to move into Northern California and other neighboring regions, the researchers say. Other strains of the fungus have been found in people in San Francisco and Los Angeles, and in a bottlenose dolphin as far south as San Diego...

Also see: http://www.livescience.com/health/deadly-new-fungus-oregon-100422.html

 

[Missouriwatcher]

Re: Cryptococcus gattii fungus seen in Pacific Northwest USA with 25% fatality rate among known infections

Projecting Global Occurrence of Cryptococcus gattii

"...An ongoing outbreak in western Canada strengthens the case that the range of the pathogen has expanded...More than 50 tree species have yielded C. gattii especially from decayed hollows suggesting a possible ecologic niche...

Cryptococcosis cases increased in Africa during 1947?1968, presumedly in association with the emergence of AIDS in the Congo River basin...

During the previous 2 decades, the increased pace of discovery produced a new appreciation of the 2 major pathogenic species, namely, C. neoformans and C. gattii. This study aimed to critically examine published information about associated tree species, ecology, and geographic occurrence of C. gattii to infer its environmental distribution...

C. gattii was easily and reliably differentiated from C. neoformans on creatinine dextrose bromthymol blue (CDB) medium...

...C. gattii affects a wide variety of native and domestic animals in regions of known clinical presence. Because, in comparison with human clinical samples, veterinary samples are less frequently analyzed for and diagnosed with C. gattii infection and subsequently reported, we suggest that the actual infection rates of C. gattii in animal populations are possibly much higher than presently known...

...in India the environmental prevalence of C. gattii appears more pervasive than the reported prevalence of the fungus in clinical specimens...

...Evidently, C. gattii is established ecologically in trees other than Eucalyptus in many parts of the world...Angiosperms other than Eucalyptus spp. have been reported positive for C. gattii from North America, South America, Africa, and India...Two prominent examples are Ficus spp. and Terminalia spp. (almond) trees...

...The 54 tree species recorded positive for C. gattii are native to tropical, subtropical, and temperate regions of the world. Additionally, many of these trees are more widely distributed than their documented native range(s) indicate...A corollary of this environmental distribution of the fungus is the diagnosis of autochthonous C. gattii cryptococcosis in native and domestic animals in Europe, Africa, Australia and New Zealand, and the Western Hemisphere, suggesting that habitats of many of these animals overlap ecologic niches with the fungus...

...C. gattii potentially can be dispersed through export of trees and woody products, air currents, water currents, and biotic sources, such as birds, animals, and insects..."
http://www.cdc.gov/eid/content/16/1/14.htm

 

[sharon sanders]

Re: Cryptococcus gattii fungus seen in Pacific Northwest USA with 25% fatality rate among known infections

<table id="apex_layout_271110100662109808" class="formlayout" summary=""><tbody><tr><td align="right" nowrap="nowrap">Archive Number</td> <td colspan="1" rowspan="1" align="left" nowrap="nowrap">20100426.1341</td></tr><tr><td align="right" nowrap="nowrap">Published Date</td> <td colspan="1" rowspan="1" align="left" nowrap="nowrap">26-APR-2010</td></tr><tr><td align="right" nowrap="nowrap">Subject</td> <td colspan="1" rowspan="1" align="left" nowrap="nowrap">PRO/AH/EDR> Cryptococcus gattii, human, animal - Canada, USA</td></tr> </tbody></table>
CRYPTOCOCCUS GATTII, HUMAN, ANIMAL - CANADA, USA
************************************************
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>

Date: Thu 22 Apr 2010
From: Mary Jane Gore <mary.gore@duke.edu> [edited]


A newly discovered strain of an airborne fungus has caused several
deaths in Oregon and seems poised to move into California and other
adjacent areas, according to scientists at Duke University Medical
Center [see Byrnes EJ III, Li W, Lewit Y, Ma H, Voelz K, et al:
Emergence and Pathogenicity of Highly Virulent _Cryptococcus gattii_
Genotypes in the Northwest United States. PLoS Pathog 2010. 6(4):
e1000850; available from
<http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000850>].

"This novel fungus is worrisome because it appears to be a threat to
otherwise healthy people," said Edmond Byrnes III, a graduate student
in the Duke Department of Molecular Genetics and Microbiology.
"Typically, we see this fungal disease associated with transplant
recipients and HIV-infected patients, but that is not what we are
seeing." Byrnes and other Duke co-authors work in the laboratory of
senior author Joseph Heitman, MD, PhD, and chair of the Department of
Molecular Genetics and Microbiology.

Their new work on the emergence and virulence of the new genotypes of
_Cryptococcus gattii_ fungi in the United States was published online
in PLoS Pathogens on 22 Apr 2010.

The mortality rate for recent _C. gattii_ cases in the Pacific
Northwest is running at approximately 25 percent out of 21 cases
analyzed in the United States, compared to a mortality rate of 8.7
percent out of 218 cases in British Columbia, Canada, the researchers
said. Most have a more complicated clinical course than people
infected with the more common _Cryptococcus neoformans_.

Because the strain is so virulent when it infects some humans and
animals, the researchers are calling for greater awareness and
vigilance. Testing involves culturing the fungus and then sequencing
its DNA to learn whether it is the virulent or more benign strain,
which could affect treatment plans.

Some strains of _C. gattii_ are not more virulent than _C.
neoformans_, for example, but doctors need to know what type they are
dealing with, Byrnes said. Using molecular techniques, the
geneticists uncovered clues that showed the Oregon-only fungal type
most likely arose recently, in addition to an outbreak of _C. gattii_
that began in Canada in 1999 that has now spread into Washington and Oregon.

Symptoms can appear 2 to several months after exposure, and may
include a cough lasting weeks, sharp chest pain, shortness of breath,
headache (related to meningitis), fever, nighttime sweats, and weight
loss. In animals the symptoms are a runny nose, breathing problems,
nervous system problems, and raised bumps under the skin. While _C.
gattii_ can be treated, it cannot be prevented; there is no vaccine.

The new type of _C. gattii_ reproduces both sexually and asexually.
The more virulent strain may have genetically recombined with related
but less harmful strains. This novel genotype is highly virulent
compared with similar isolates of _Cryptococcus_ that are not causing
disease outbreaks. The researchers found that the novel genotype
(VGIIc) is now a major source of _C. gattii_ illness in Oregon.
Because _C. gattii_ types had been found in tropical areas before,
co-lead author Wenjun Li, MD, PhD, of Duke Molecular Genetics and
Microbiology, speculates that environmental changes may be
responsible for the evolution and emergence of this pathogen.

Determining the exact origin of the VGIIc type is difficult, and
sampling thus far has failed to turn up isolates in Oregon soil,
water, or trees. "We are trying to put together the evolutionary
story of where these types come from by closely studying the genetics
of all samples possible," said Yonathan Lewit, a research associate
also in Duke Molecular Genetics and Microbiology. He said that cell
components called mitochondria may play a role in the increased
virulence of certain types.

VGIIc, the new Oregon strain, has yielded dozens of isolates in many
specimens, including from domesticated animals: cats, dogs, an
alpaca, and a sheep. "Most of those are nonmigratory animals," Byrnes
said, explaining that the animals probably didn't bring the pathogen
from some other region, and most likely acquired it locally.

--
Mary Jane Gore
Sr. Science Writer at Duke University Medical Center
Raleigh-Durham, North Carolina
USA
<mary.gore@duke.edu>

[_C. gattii_ is endemic in eucalyptus-growing regions of Australia
and Papua New Guinea (the bark and leaves are apparently an
ecological habitat for _C. gattii_), and in parts of Africa, the
Mediterranean region, India, south-east Asia, Mexico, Brazil, and
Paraguay (see
<http://www.mycology.adelaide.edu.au/Fungal_Descriptions/Yeasts/Cryptococcus/C_gattii.html>).
Its occurrence in latter regions lacking eucalyptus trees suggests
that additional environmental niches for this fungus are yet to be discovered.

Unlike cryptococcal infections among immunodeficient individuals
(such as patients with AIDS/HIV or organ transplant recipients),
which are predominantly caused by _Cryptococcus neoformans_, 70-80
percent of cryptococcal infections among immunocompetent hosts are
caused by _C. gattii_; _C. gattii_ infections are mainly pulmonary
(75 percent), although neurologic (8 percent) and combined (9
percent) infections are seen. The news release above also notes that
the outbreak strains in the Pacific Northwest are particularly
virulent and associated with high mortality.

_C. gattii_ has caused a large-scale outbreak since 1999 that
involves terrestrial and marine mammals and several hundred humans in
British Columbia and the Pacific Northwestern US. The route by which
_C. gattii_ was introduced into North America has not been
established, although importation of contaminated eucalyptus trees or
seeds, or wooden pallets or crates made from eucalyptus that are not
routinely inspected for microbial contamination upon entry into
Canada or the US has been implicated, with subsequent spread possibly
by human and other animal activity (Kidd SE, Bach PJ, Hingston, AO,
Mak S, et al: _Cryptococcus gattii_ dispersal mechanisms, British
Columbia, Canada. Emerg Infect Dis. 2007 Jan 13(1): 51-7; available
from <http://www.cdc.gov./ncidod/eid/13/1/51.htm>). For a further
discussion of possible mechanisms of dispersal, please see the prior
ProMED-mail post, _Cryptococcus gattii_, human, animal - Canada, USA
(02): BC 20080220.0693.

Maps of the Pacific Northwest are available at
<http://www.gonorthwest.com/Visitor/about/map.htm> and the
HealthMap/ProMED-mail interactive map at
<http://healthmap.org/r/01e8>. - Mod.ML]

</pre>

 

[tropical]

Re: Cryptococcus gattii fungus seen in Pacific Northwest USA with 25% fatality rate among known infections

http://www.aspergillus.org.uk/education/Fungal_Kingdom%5B1%5D.pdf

A REPORT FROM THE AMERICAN ACADEMY OF MICROBIOLOGY

"A rise in Cryptococcus gattii infections. It has been suggested that C. gattii takes advantage of some genetic changes and possibly alterations in its ecosystem, and that recent dry conditions during the summers on Vancouver Island have encouraged an outbreak of C. gattii infections in the area. Prior to the outbreak of cryptococcal disease in British Columbia, Canada, the environmental niche of Cryptococcus gattii was thought to be restricted to tropical or semi-tropical climates. C. gattii as the causative agents of an emerging infectious disease is an example of the role of micro-environmental changes, including climate change, that will increase the potential for exposure to pathogenic fungi to humans, domestic and wildlife. How the organism came to Vancouver Island and is now spreading beyond to the British Columbia mainland and into the United States in Washington and Oregon cannot be known for certain, but likely has involved human activities.
...

Mold in the space station. Air in space vehicles is often contaminated with fungal spores. Mold has become a major problem for the Russian space station Mir, where it has been found growing in sensitive electronic equipment.

Fungal outbreaks following earthquakes. Outbreaks of Coccidioides infections have occurred in California following earthquakes in the 1990s that disturbed soil leading to airborne spores and infections in humans."