Posted on 08/31/2007 9:49:04 AM PDT by SwinneySwitch
Heavy summer rains along the Texas-Mexico border always raise concerns over dengue fever, a mosquito-borne illness that is also called break-bone fever because of the severe body aches it causes. The border region has seen periodic outbreaks of the tropical virus, which is carried by a mosquito that thrives in much of Texas. And public health officials worry that the more severe form of the disease, which can cause internal bleeding and death, appears to be on the rise.
Current flu vaccines and antiviral drugs don't work on dengue, but research into better treatments has been slow. Humans are the only creatures that get sick from the virus, and scientists didn't have a good animal model to use in studying dengue.
Researchers at Southwest Foundation for Biomedical Research now have developed a laboratory mouse that could change that. Scientists have successfully implanted the mice with the type of human immune cells, called dendritic cells, that get attacked by the invading dengue virus.
"We think our cells have receptors for this virus while other primates and animals do not," said Rebeca Rico-Hesse, a foundation scientist who developed the lab model by transplanting human cord blood cells into an adult mouse.
She now has a grant from the Robert J. Kleberg and Helen C. Kleberg Foundation to develop ways of transplanting human immune cells into newborn mice, which would make them a better tool for testing vaccine candidates and studying factors that contribute to disease severity.
Dengue is primarily a risk to travelers who visit Latin America and Asia. Most people get the milder form of the disease and recover after a few painful weeks. But more severe forms of dengue can cause internal bleeding and death, and scientists worry that this form is on the increase.
The mosquito that spreads dengue, Aedes aegypti, lives in Texas, and public health officials worry that the disease could move across the Mexican border and take hold in South Texas.
"We think it's just a matter of time (until) enough of our mosquitoes get infected and there is actual transmission of dengue in the United States," Rico-Hesse said.
Dengue has been an especially difficult problem for scientists because there are four viruses that can cause the disease, said James LeDuc, director of global health at the University of Texas Medical Branch in Galveston. Plus, he said, exposure to one form of the virus may actually prime people to get sicker from the other dengue viruses.
"So rather than making one vaccine, you are actually trying to make four vaccines and balance the immune response so you don't set people up for a more severe disease," said LeDuc. "It's one of the challenges we have faced forever.
"Having a mouse, especially if it mimics human response, will help this research," he added.
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ctumiel@express-news.net
Ping!
If you want on, or off this S. Texas/Mexico ping list, please FReepMail me.
This doesn't add much to confidence.
Nogales working furiously to prevent raw-sewage spill (into USA!)
http://www.freerepublic.com/focus/f-news/1887736/posts
Mosquito born illnesses can and have been contained but it takes international cooperation; that's something many freepers can't handle.
When I was in the tropics, I was bitten countless times. Thank God nothing happened to me
When I was in the tropics, I was bitten by mosquitoes countless times. Thank God nothing happened to me
Open border lover!
FYI
Mosquitoes know NO borders.
History of the Disease
Outbreaks resembling dengue fever have been reported throughout history.[27] The first definitive case report dates from 1789 and is attributed to Benjamin Rush, who coined the term “breakbone fever” (because of the symptoms of myalgia and arthralgia). The viral etiology and the transmission by mosquitoes were only deciphered in the 20th century. Population movements during World War II spread the disease globally.
on
If they killed the skeeters they wouldn’t have to worry about it.
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