Posted on 08/04/2004 9:10:07 PM PDT by Taka No Kimi
Washington, August 4
Environmental changes, such as replacing forests with ranchland, combined with genetic mutations, can produce viruses like SARS and HIV, according to a research from the University of Texas Medical Branch (UTMB).
Researchers reached this conclusion after studying viruses from two late-20th-century outbreaks of Venezuelan equine encephalitis (VEE) - a deadly illness that can cause brain inflammation in horses and people - in Mexico and compared them with a similar virus that does not usually infect horses or people.
They suggested that replacing forests with ranchland along a 805-kilometre-long, 32- to 80-kilometre-wide stretch of Mexico's and Guatemala's Pacific coastal plains put extreme evolutionary pressure on the VEE virus strain that was prevalent there.
In a paper published yesterday in the journal "Proceedings of the National Academy of Sciences," the researchers suggested that, as deforestation wiped out the Culex sub-species of mosquitoes, a single genetic mutation in the virus allowed it to move into a new niche, increasing the virus's ability to infect and be transmitted by a different mosquito species, Ochlerotatus taeniorhynchus. This species prefers to feed on horses and other large mammals.
"What's troubling," said Professor Scott C Weaver, director for emerging infectious diseases at UTMB's Centre for Biodefence and Emerging Infectious Diseases, and senior paper author, "is that this shows a virus can find a simple genetic mutation that allows it to switch to a new species of mosquito that has the capacity to infect horses and people."
Bunch of Crapola B.S.
/sarcasm
.............ancient war gaming......
/sarcasm
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