Pathogens that affect humans--1,407 total!

[Guest guest]

Hi, all.

I think this is an intereesting news story. This guy has counted

them up! There are 1,407 pathogens that affect people! Looks like

a lot of work ahead for the Infection and Inflammation group!

Rich

Feb. 20, 2006, 11:03AM

Scientists See Growing Animal-Disease Risk

By ANDREW BRIDGES Associated Press Writer

© 2006 The Associated Press

ST. LOUIS — Humans risk being overrun by diseases from the animal

world, according to researchers who have documented 38 illnesses

that have made that jump over the past 25 years.

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That's not good news for the spread of bird flu, which experts fear

could mutate and be transmitted easily among people.

There are 1,407 pathogens _ viruses, bacteria, parasites, protozoa

and fungi _ that can infect humans, said Mark Woolhouse of the

University of Edinburgh in Scotland. Of those, 58 percent come from

animals. Scientists consider 177 of the pathogens to be " emerging "

or " re-emerging. " Most will never cause pandemics.

Experts fear bird flu could prove an exception. Recent advances in

the worldwide march of the H5N1 strain have rekindled fears of a

pandemic. The virus has spread across Asia into Europe and Africa.

Controlling bird flu will require renewed focus on the animal world,

including the chickens, ducks and other poultry that have been

sacrificed by the tens of millions to stem the progress of the

virus, experts said at a news conference late Sunday at the annual

meeting of the American Association for the Advancement of Science.

" The strategy has to be looking at how to contain it in the animal

world, because once you get into the human side, you're dealing with

vaccines and antiretrovirals, which is a whole new realm, " said Nina

Marano, a veterinarian and public health expert with the National

Center for Infectious Diseases.

Bird flu has killed at least 91 people _ most of them in Asia _

since 2003, according to the World Health Organization. It appears

to kill about half the people it infects. However, should it mutate

so it can pass from human to human, it likely will grow far less

deadly, said Dr. Stanley Lemon, of the University of Texas Medical

Branch at Galveston.

" It is very unlikely that it would maintain that kind of case

mortality rate if it made the jump, " Lemon said.

Each year for the last 25 years, one or two new pathogens and

multiple variations of existing threats have infected humans for the

first time. Without speculating about earlier infection rates,

Woolhouse told reporters it appears impossible the human species

could endured such a rapid pace of new infections over thousands of

years.

" Humans have always been attacked by novel pathogens. This process

has been going on for millennia. But it does seem to be happening

very fast in these modern times, " Woolhouse said.

Woolhouse argues that either many of those diseases and other

afflictions will not persist in humans or that there is something

peculiar today allowing so many of them to take root in humans.

One explanation may be the recent and wide-scale changes in how

people interact with the environment in a more densely populated

world that is growing warmer and in which travel is faster and move

extensive, Marano said. Those changes can ensure that pathogens no

longer stay restricted to animals, she added. Examples from recent

human history include HIV, Marburg, SARS and other viruses.

That prospect leaves open the question of what future threats await

humans.

" It always surprises us. We think that avian flu will be the next

emerging disease. My guess is something else might come out before

that, " said Alan Barrett, of the University of Texas Medical Branch

at Galveston. " It's very hard to anticipate what comes next. "