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 to grow.
"That means that if I have a cell where that gene product is not there, the virus will not grow efficiently," he says.
Garcia-Blanco 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?
"That 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 dengue.