The growing Danger from the Zoonoses.

Zoonoses are defined by the WHO as “Diseases and infections which are naturally transmitted between vertebrate animals and man”.
 
In an article in the scientific American today, David Biello says that the best way to beat bird flu and other zoonotic diseases, he says, is to keep humans and wildlife healthy.
 
A zoonotic agent may be a bacterium, virus, fungus, parasite, or other communicable agent.

Zoonoses cover a broad and growing range of diseases and they can be transmitted by bacterium, virus, fungus, parasite, or a number of other (also growing) agents.

A recent study shows that these zoonoses such as H5N1 bird flu, West Nile and Ebola now account for as much as 58 percent of human pathogens and the number is growing fast.
 
In just the past five years, WHO has identified more than 1,000 epidemics stemming from such pathogens.
 
“There are more flu infections in more countries than ever before,” said veterinarian William Karesh, head of the Field Veterinary Program of the Wildlife Conservation Society (WCS), during a WSC Conferance in New York City last week.
 
These diseases are hard to stop because they are not only spread by wild animals, mosquitoes and the like but, even more commonly, by billions of livestock animals, such as chickens, ducks and geese raised for food in vast factory farms.
 
Zoonotic outbreaks are triggered by a range of factors, including man-made changes to natural habitats that bring humans into contact with wildlife as well as airplanes and other forms of transport that allow “speedy, long-range dissemination of any disease agent,” says veterinarian Arnon Shimshoni of The Hebrew University of Jerusalem.
 
“There is an artificial distinction between the health of wildlife, livestock and people,” Karesh said. Sickness in one of these groups, can mean sickness in all.
Credits:
 
 
 

Bird-Flu Mutates to Mix with Swine-Flu

Researchers have identified a new strain of swine influenza—H2N3—which is a mutated virus gene, composed of avian and swine influenza genes.
H2N3 which belongs to the group of H2 influenza viruses that last infected humans during the 1957 pandemic.
Department of Agriculture Seal

The research team at Agricultural Research Service, studied an unknown pathogen that in 2006 infected two groups of pigs at separate production facilities.

Both groups of pigs used water obtained from ponds frequented by migrating waterfowl.

Molecular studies indicated the unknown pathogen was an H2N3 influenza virus that is closely related to an H2N3 strain found in mallard ducks. But this was the first time it had been observed in mammals.

Influenza viruses have eight gene segments, all of which can be swapped between different virus strains.

Two of these gene segments code for virus surface proteins that help determine whether an influenza virus is able to infect a specific host and start replicating—the first step in the onset of influenza infection.

In the newly isolated swine H2N3, the avian H2 and N3 gene segments mixed with gene segments from common swine influenza viruses.

This exchange—and additional mutations—gave the H2N3 viruses the ability to infect swine. Lab tests confirmed that this strain of H2N3 could also infect mice and ferrets.

These findings provide further evidence that swine have the potential to serve as a “mixing vessel” for influenza viruses carried by birds, pigs and humans. It also supports the need to continue monitoring swine—and livestock workers—for H2-subtype viruses and other influenza strains that might someday threaten swine and human health.

Results of this study were published online this week in the Proceedings of the National Academy of Sciences of the United States of America.

ARS is the U.S. Department of Agriculture‘s chief scientific research agency.

The research Scientists:

Agricultural Research Service (ARS) veterinarians Juergen Richt, Amy Vincent, Kelly Lager and Phillip Gauger conducted this research with Iowa State University (ISU) visiting scientist Wenjun Ma, ISU veterinarian Bruce Janke and other colleagues at the University of Minnesota and St. Jude Children’s Research Hospital. The ARS veterinarians work at the agency’s National Animal Disease Center in Ames, Iowa.

Sources:

http://www.ars.usda.gov/News/docs.htm?docid=1261

www.birdflubreakingnews.com