Nature: Biodiversity loss = more human disease

[urbantravels]

http://www.nature.com/news/2010/101201/full/news.2010.644.html

Biodiversity protects ecosystems against infectious diseases, researchers have concluded. The finding suggests that loss of species from an environment could have dangerous consequences for the spread and incidence of infections, including those that affect humans.

Felicia Keesing, a biologist at Bard College in Annandale, New York, and her colleagues reviewed several dozen studies published in the past five years and found that the link holds true across various ecosystems, pathogens and hosts. "A pattern is emerging which shows that biodiversity loss increases disease transmission," says Keesing, whose study is published today in Nature.

The researchers don't know why the effect occurs. But they speculate that species that are better at buffering disease transmission for example because they have low rates of reproduction or invest heavily in immunity tend to die out first when diversity declines, whereas species that have high rates of reproduction or invest less in immunity and thus are more likely to be disease hosts survive for longer.

The review analyses studies of 12 diseases, including West Nile fever and Lyme disease, in ecosystems around the world. In every study, the diseases became more prevalent as biodiversity was lost. For example, three studies showed that a decreased diversity of small mammals in an area causes the prevalence of hantaviruses which induce fatal lung infections in humans in host animals to rise, thereby increasing the risk to humans.

 

[Merry]

Very interesting. Thank you, urbantravels.

Can you recommend books on the subject of pathogens passed from wildlife - and livestock - to humans? Nothing terribly technical because, although I have a long-standing interest in biology, my college education was in English (and, later, computer science). A history on the subject might be good.

An aside: deer mice are really elegant little creatures.

Merry

 

[urbantravels]

I'm reading a book right now called "The Coming Plague", but it's quite an undertaking. It's easily the size of "Osler's Web" or "And the Band Played On," and a big portion of the opening chapters are devoted to riveting, but highly gruesome, tales of outbreaks of hemorrhagic fevers in Africa and South America. The book is from 1995, so it's not new, but has by no means become untimely.

http://www.amazon.com/Coming-Plague-Emerging-Diseases-Balance/dp/0140250913

I personally learned the most about how viral diseases jump from animals to humans by listening to Vincent Racaniello's "Virology 101" lectures online, but it's an investment of time.

Heck, I'd say start with the Wikipedia article on zoonosis.

http://en.wikipedia.org/wiki/Zoonosis

 

[Merry]

Thank you, urbantravels. I will check if the library has The Coming Plague. Also the online lectures. But first I can look at Wikipedia.

After I posted I remembered that I had an illness a long time ago that was connected to birds and bats. It is the fungal infection histoplasmosis, also known as Ohio River Valley fever. The infection is airborne, on dust particles, and is found in especially high concentrations in bird and bat droppings. I only know that I had it because of scars on my lungs that showed up on an xray. I have no idea when I was infected - sometime during childhood.

My ex-husband, who also grew up in Ohio, on a chicken farm, has scarred retinas from histoplasmosis. And a few years ago I talked to someone I'd known in high school, and she said her brother was going to have to give up teaching because histoplasmosis had damaged his eyesight.

My recommendation to you: Stay in California!

 

[urbantravels]

Hey, we're not a disease-free paradise out here, you know. In fact recent conversations on this board have centered around the possibility that Los Angeles might have been ground zero for XMRV jumping from mice into humans, on account of the Los Angeles County Hospital outbreak of something that might have been ME in 1934.

 

[Merry]

Yes, that's an intriguing about the California mice capable of carrying XMRV and then the story of an outbreak of illness at the Los Angeles County Hospital. I read the two pages from a medical journal (Mark posted a link - on which thread?) describing in detail the hospital outbreak. But I was left wondering if anyone followed up on those patients six months, a year, or more, later.