Dengue fever is a mosquito-borne disease that's becoming more of a
problem around the world. The range of dengue-carrying mosquitoes has
spread from tropical into sub-tropical areas. And some countries have
had ongoing dengue outbreaks that have made tens of thousands of people
According to Duke University scientist Mariano
Garcia-Blanco, dengue fever is often called break-bone fever because of
its painful symptoms.
"It's a very severe flu-like illness that
makes people have headaches, usually behind the eyes. You get joint
pain, pain in the muscles, very much what people call flu-like
symptoms. It also, in some cases, people can actually have much more
severe symptoms. They can go on to lose fluids. They can then go into
shock, and then death can ensue."
Garcia-Blanco says dengue is a
relatively simple virus, with several approaches scientists could take
to try to block its action. One way would be to manipulate the genes of
the hosts, either mosquitoes or humans. To start, Garcia-Blanco looked
at genes in a fruit fly that he infected with dengue. He says he found
dozens of genes, and parts of genes, that the host needs for the virus
"That means that if I have a cell where that gene product is not there, the virus will not grow efficiently," he says.
then tested several of these gene factors in mosquitoes. He found
several of these mosquito genes were required for dengue to grow inside
that insect. By manipulating those genes, Garcia-Blanco thinks he would
be able to impede the growth of dengue virus in mosquitoes.
But what about in humans? Would this approach work in people, or would manipulating human genes make people sick?
is not always the case. As a matter of fact, most of the medicines that
we take - think about cholesterol-lowering drugs - they affect things
in the host. They affect activities that are part of our bodies. So if
you could inhibit these activities - these required host factors, as we
call them - then you would prevent viral infection in humans, and that
would be a drug. If you do it in mosquitoes, that would be an
intervention to transmission."
Garcia-Blanco says this is
still just basic science, and he thinks he's at least a decade from
finding a clinical intervention based on his research. But he says that
this kind of approach has potential for curbing the further spread of