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Monday, February 4, 2013

West Nile Virus--The Screams, the Stops, and the Cure

West Nile Virus--when those three words hit the media your relatives scream at flies and you itch just listening. With Mississippi reporting 17 more cases Aug. 20, and Texas spraying insecticide all over Dallas, mosquito-phobia's everywhere. Rightly so--the first 2012 West Nile death victim in New York died this week, and 2012 has suffered more WNV cases through August than any other year since we first detected West Nile. How does WNV work, and how do doctors fight it?

According to a 2006 paper in the Journal of Virology, the virus shares the Flaviviradae family with dengue and yellow fever. Molecules like its E protein help it attach to receptors on your body cells, then open their outer membranes to fuse with them. Unlike your cells, which have DNA and RNA, the virus only has one strand of RNA. Once it fuses with your cells, it takes over your endoplasmic reticulum--your cells' highway system--and makes a copies of its RNA that it wraps using your Golgi bodies--your cell's packaging system. The cell bursts, and these packages, virions, escape. Deadly WNV attacks the neurons on your brain stem; you can imagine you don't want the cells there bursting.

Right now doctors primarily treat the flu-like symptoms with rest, hydration, and anti-inflammatories, and try to reduce pressure caused by brain swelling. Doctors may prescribe the general anti-viral Acyclovir before they know which virus they're dealing with, just in case the encephalitis comes from something we CAN treat. They may prescribe Ativan for seizures.

In 2009 researchers found a possible way to block the virus from fusing into your neurons. Their antibody, MAb E16, blocks the chemical process on the E protein that allows the virus to penetrate the cell membrane. There's also a possible vaccine, as researchers just last month constructed a baculovirus with WMV's E proteins. Chemicals in the bacterium signal neighboring cells to release cytokines, or messages to the body's defenses to rush to the rescue. That test-mouse's body now knows next time it senses those E proteins to kill the virus, instead of letting it fuse with its cells.

Both these ideas still need further testing, so dump standing water, spray your backyard, and wear repellant--remember, mosquitos like dusk AND dawn. With the right precautions, you won't have to worry, and if medicine keeps moving in the right direction, soon you'll have to worry even less.

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