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West Nile Virus. What is West Nile Virus?. A mosquito transmitted virus that causes mild to severe illness and is commonly found in birds, humans and other mammals. New York. Israel. Uganda. History. 1937 : WNV was first isolated in the West Nile province of Uganda
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What is West Nile Virus? A mosquito transmitted virus that causes mild to severe illness and is commonly found in birds, humans and other mammals.
New York Israel Uganda History • 1937: WNV was first isolated in the West Nile province of Uganda • 1950’s: WNV was first recorded epidemic in Israel • 1999: WNV first appeared in the U.S. in New York (only 10 years ago!)
These front covers of The New Yorker depict West Nile Virus as a current event in 1999 and 2000. What are the themes or narratives of these illustrations?
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Activity in the U.S. National Center for Infectious Diseases West Nile Virus Activity
Transmission Bird to bird transmission has been demonstrated in caged birds Mosquitoes become infected when they bite birds infected with WNV Mammals bitten by infected mosquitoes may test positive for WNV although some may not get ill
Transmission • Most common • Infected mosquito bite • Rare transmission • Donate blood (now screened for WNV) • Mother to unborn child • From organ transplant
In the Human Body • West Nile Virus multiplies and may cross the blood-brain barrier
In the Human Body • Normally, this barrier prevents bacteria and viruses from getting to the brain • When they pass, an immune response is activated • This can lead to the most dangerous symptom of WNV, encephalitis (brain inflammation or swelling)
Serious Symptoms • About 1 out of 150 WNV infected people • high fever • headache • neck stiffness • coma • tremors • convulsions • muscle weakness • vision loss • numbness and paralysis • These symptoms may last several weeks, and neurological effects may be permanent
Mild Symptoms • Up to 20% (1 out of 5) of WNV infected people • fever • headache • body aches • nausea • vomiting • sometimes swollen lymph glands • a skin rash on the chest, stomach or back. • Lasts from a few days to weeks
No Symptoms • Approximately 80% of people (about 4 out of 5) who are infected with WNV will not show any symptoms at all
Other Affects on Human Populations • Keeps people from going outdoors during warmer months • Keeps people from travelling to other countries with a higher prevalence • Parents shelter their children more by keeping them at home and preventing them from outdoor exercises • Although WNV is potentially dangerous, the risk is not high enough to be this precautious
How many of you have been bitten by a mosquito? Now, how many of you have been diagnosed with West Nile Virus? The risk of getting West Nile Virus is actually quite low especially for children and adolescents.
Just Be Safe: Practice the 7 D’s DRAIN any standing water that may produce mosquitoes. DAWN and DUSK are times to avoid. These are the times when mosquitoes are most active. DRESS appropriately by wearing light colors, long sleeves and pants when going near mosquito infested areas. DEFEND yourself against mosquitoes by using an effective insect repellent. Make sure you follow all label directions! DOOR and window screens should be in good working condition. This will prevent mosquitoes from entering your home. DISTRICT personnel are available to address any mosquito problem you may be experiencing.
Mosquito Repellent Fact • Mosquitoes key in on carbon dioxide (CO2) signatures of warm-blooded animals • Humans have a CO2 signature of their own that mosquitoes love the best • Citronella, a prime ingredient of insect repellent, sprayed in the air confuses mosquitoes because it interferes with their ability to “smell” CO2
What about the Swine Flu we’ve been hearing lots about? How does it compare to West Nile Virus?
West Nile Virus vs. Swine Flu Similarities 1. Both viruses 2. Neither currently have vaccinations 3. Both present flu-like symptoms 4. Both originated in animals 5. Both can easily be prevented by taking the necessary precautions Differences 1. West Nile is transmitted by mosquitoes and Swine Flu by viral human contact 2. West Nile was originally detected in Uganda, Swine Flu in Mexico 3. Flu viruses typically arise in colder months where West Nile is prone in warmer months
Avoid Swine Flu: Practice the 3 C’s 1CLEAN Wash your hands often. Scrub your hands for at least 20 seconds with soap and water. Cover your cough. Use a tissue to cover your mouth and nose when you cough or sneeze. 2COVER 3CONTAIN Contain germs by steering clear of those who are sick. If you do get sick, stay at home until you are well again, so that you do not spread more germs.