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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