Two men, ages 86 and 37, died from WNV infections in their brain tissue, known as West Nile encephalitis/meningitis. Normally West Nile is asymptomatic or takes a milder, fever-like form in people with healthy immune system, but these two men had other chronic health problems that left them susceptible.
WNV is a flavivirus that naturally resides in birds and is transferred by mosquito bites. It arrived in the US in 1999, supposedly from birds at the Bronx Zoo, and has since spread all across the US and to our neighboring countries. WNV reminds me of how scary some viruses can be: they're hiding invisibly in so many unavoidable things like food, friends, air, and mosquitos. We can only hope that our body can handle whatever gets inside of us, which it does grandly most of the time.
It's also pretty amazing that WNV can be deadly in birds, horses, and humans, so being the molecular biologist I am, I looked up its cellular "tropotope". It's still unknown, but possible suspects include well-conserved receptors such as Toll-like receptor 3, usually used to recognize and combat infection by dsRNA viruses, and Integrin, used to secure the cell to the extracellular matrix.