Deadly strain of airborne fungus spreading among healthy people and animals in U.S., scientists warn

Deadly strain of airborne fungus spreading among healthy people and animals in U.S., scientists warn

By Mail Foreign Service

Last updated at 3:36 PM on 23rd April 2010

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A deadly strain of fungus is quietly spreading among animals and people in the U.S. and Canada, scientists have warned.

The airborne Cryptococcus gattii usually only infects transplant and Aids patients and others with weak immune systems.

But researchers have raised concerns as the new strain is genetically different, meaning healthy people are at risk.

Over the past 11 years there have been about 220 cases reported in British Columbia while since 2004, doctors in Washington and Oregon have reported about 50.

Among the total 270 cases, 40 people have died from overwhelming infections of the lungs and brain.

However, researchers have suggested the bug is changing possibly due to climate change.

Scientists are now warning C. gattii, which has been found in Western North America and the Canadian province of British Columbia, could spread further.

Edmond Byrnes of Duke University in North Carolina, who led the study which was published today, said: ‘This novel fungus is worrisome because it appears to be a threat to otherwise healthy people.

‘The findings presented here document that the outbreak of C. gattii in Western North America is continuing to expand throughout this temperate region.

‘Our findings suggest further expansion into neighbouring regions is likely to occur and aim to increase disease awareness in the region.’

The fungus is usually found in forests, on trees and in soil. Those who have got sick usually work in jobs such as forestry or construction.

Symptoms - a cough lasting for weeks, sharp chest pain, shortness of breath, headache, fever, nighttime sweats and weight loss - usually take up to six months to develop after exposure.

Dr Julie Harris, a specialist in fungal diseases at the Centers for Disease Control and Prevention, Atlanta, said: ‘This makes it very challenging for us to find out what the most important exposure was.

‘Often we'll be able to tell if a patient was exposed, for example, to salmonella.

‘They'll get sick the next day, and they can remember what they ate the day before. But with this disease, we're really challenged. It can take from two months up to a year for the disease to manifest itself.’

Researchers are also concerned by the number of different animals species getting infected.

Domestic cats and dogs lead the list, but there have been confirmed reports in sheep, goats and horses, in elk and llamas, even in porpoises and dolphins whose infected corpses have washed up on beaches.

The report added: ‘From 1999 through 2003, the cases were largely restricted to Vancouver Island.

‘Between 2003 and 2006, the outbreak expanded into neighbouring mainland British Columbia and then into Washington and Oregon from 2005 to 2009.

‘Based on this historical trajectory of expansion, the outbreak may continue to expand into the neighboring region of Northern California, and possibly further.’