West+Nile+Virus

=West Nile Virus=

**Description of virus that causes the disease.**
== = =
 * virons consist of an envelop and a nucleocapsid
 * virons are spherical and measure 40-50 nm in diameter
 * the envelop has surface projections
 * the core is isometric and has a diameter of 25-30 nm
 * the capsid shells of virons are single layer

**Viral Specificity:**

 * its a illness that is spread from mosquito's to humans
 * the mosquito bites the host and transmits the virus into the blood
 * it cannot be passed from human to human
 * the virus travels through the blood stream and affects the different organs in the human body
 * it affects the central nervous system

**Symptoms and progression of the disease:**
West Nile virus produces three different outcomes: The second febrile stage has an incubation period of 2 to 8 days symptoms of this stage include: Rarer outbreaks (encephalitis)
 * asymptomatic infection
 * mild febrile syndrome (West Nile Fever)
 * neuroinvasive disease (West Nile meningitis or encephalitis)
 * the ratio for these three stages is roughly 110:30:1
 * drowsiness, pain in joints, rash, swollen lymph node, weakness
 * headache, chills, diaphoresis,
 * symptoms usually resolve within 7 to 10 days
 * fatigue can persist for weeks
 * swollen lymph nodes can last up to 2 months
 * similar early symptoms but also decreased level of consciousness
 * spinal cord could get infected
 * hepatitis, myocarditis, nephritis, pancreatitis
 * recovery is long

**Common Methods of Transmission:**

 * The virus is transmitted through mosquito's vectors
 * mosquito's feed on infected birds
 * s get West Nile Virus form Birds
 * infected mosquito's feed on humans
 * Asian tiger mosquito has been found to be a vector of WNV
 * virus does not multiply as readily in mammals
 * mammals are dead-end infection (doesn't spread any further)



**Treatment and Prevention (if any):**

 * AMD3100 this drug was originally made for HIV but has shown promise against WNV encephalitis
 * there have been attempts to use ribavirin, intravenous immunoglobulin, or alpha interferon to treat infections
 * There is no vaccine for WNV
 * minimize your time out doors when mosquito's are most active
 * where long sleeve shirts
 * use insect repellent
 * make sure your screens on doors and windows are put on tight
 * reduce mosquito's breeding areas (clean out any small pool of water)


 * Miscellaneous:**
 * WNV emerged as a distinct virus around 1000 years ago
 * WNV was posted as one of the possible cause of Alexander the Greats death
 * WNV was first isolated from a feverish 37 year old women in the West Nile District of Uganda in 1937
 * The first appearance of WNV was in the western hemisphere was in 1999
 * A high level of media coverage through out 2001/2002 raised public awareness

**Resources accessed:**
Wikipedia CBC News-health-West Nile Virus www.ictvdb.org