I guess we shouldn't be surprised by the fact that our pillows are miniature zoos containing millions of fungal spores, with some species able to cause diseases and even death. Researchers at the University of Manchester have studied the fungal contamination of our pillows for the first time in seventy years and discovered that these pillows were hot beds of fungal spores. After dissecting both feather and synthetic pillows in regular use between several months and 20 years, they've "identified several thousand spores of fungus per gram of used pillow -- more than a million spores per pillow."
According to this University of Manchester news release, our pillows are small ecosystems. Here is a short quote from Professor Ashley Woodcock who led the research.
We know that pillows are inhabited by the house dust mite which eats fungi, and one theory is that the fungi are in turn using the house dust mites' faeces as a major source of nitrogen and nutrition (along with human skin scales). There could therefore be a 'miniature ecosystem' at work inside our pillows."
So what kind of fungus Woodcock and his colleagues have they found and are thes fungi dangerous for our health?
Aspergillus fumigatus, the species most commonly found in the pillows, is most likely to cause disease; and the resulting condition Aspergillosis has become the leading infectious cause of death in leukaemia and bone marrow transplant patients. Fungi also exacerbate asthma in adults.
Below is a small image of the Aspergillus fumigatus fungus (Credit: George Barron's Website on Fungi). And here is a link to a larger version of this picture.
So should we be concerned? MedPage Today says that we should, at least after spending some time in an hospital.
Upon returning home from the hospital, immunocompromised patients may face danger anew from the pillows in their own beds, according to researchers [in Manchester.]
Hospitals use plastic pillow covers to block fungal exposure. But when immunocompromised patients return home they usually have no such protection against A. fumigatus and other fungi lurking in their pillows, Dr. Woodcock said.
So should we throw away our pillows and buy new ones? WebMD Medical News gives us the answer.
How worried should we be about pillow fungus? WebMD asked indoor pollution expert William Beckett, MD, professor of environmental medicine at the University of Rochester, N.Y.
"My reaction is, 'Ho-hum. We knew this already," Beckett tells WebMD. "We culture fungus from all over the home. Wherever you look, they are there."
And Ashley Woodcock confirms.
Meanwhile, Woodcock says the current findings aren't reason to replace your pillows. After all, he points out, the finding has been -- almost literally -- staring us in the face for a very long time.
"We don't have enough evidence at the moment to throw all our bedding out," he says. "But we need to watch this space and wonder what the fungi are doing there and whether a particular kind is particularly bad."
For more information, the research work has been published as an advanced online publication by Allergy on October 14, 2005 under the title "Fungal contamination of bedding," even if it not available at the moment I'm typing this note.
And if you really want to know more about the sexual life of the Aspergillus fumigatus, you should read an article published by LiveScience last July, "Fungus may be having sex among us." Here are the opening paragraphs.
Sex was once thought to be the domain of higher life forms. But now a common fungus -- one that causes deadly infections in humans -- appears to reproduce sexually.
The fungus, aspergillus fumigatus, has also been linked to asthma. Scientists always thought it reproduced asexually, a method of simple cell division used by many microbial creatures.
A new study finds the fungus has a series of genes required for sexual reproduction. An analysis of 290 specimens revealed nearly equal proportions of two different sexes or 'mating types,' which in theory could have sex with each other, the researchers said.
Finally, you should visit the Aspergillus website -- even if some portions of the site need to be registered -- or this page at doctorfungus.com about Aspergillus species.
A last word: sleep well!
Sources: University of Manchester news release, October 14, 2005; Jeff Minerd, MedPage Today, October 14, 2005; Daniel DeNoon, WebMD Medical News, October 14, 2005; and various web sites
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