August 23rd, 2012
11:00 AM ET
The recent West Nile virus outbreak is the largest ever seen in the United States, according to new numbers from the Centers for Disease Control and Prevention.
The number of cases so far this year is the highest recorded through September since the disease was first detected in the United States in 1999. As of Tuesday, 48 states had reported human infections. The cases reported to the CDC as of Tuesday total 2,636, including 118 deaths.
Here are some fast facts about the virus. For more on what you need to know to protect yourself and your family, read Elizabeth Cohen's Empowered Patient column.
Background on the West Nile virus
– Symptoms of infection include: fatigue, fever, headache, body aches, rash, and swollen lymph nodes.
– Those who become ill may develop West Nile encephalitis, an inflammation of the brain.
– There is no vaccine or specific treatment for West Nile virus.
– The virus is spread by mosquitoes, which contract West Nile from infected birds.
– According to the CDC, only 1% of people bitten by West Nile-infected mosquitoes become seriously ill.
– It is not known how the virus arrived in the United States.
2011 - 712 cases of West Nile virus are reported in 44 states and the District of Columbia with 43 deaths.
2010 - 1,021 cases of West Nile virus are reported in 40 states and the District of Columbia with 57 deaths.
2009 - 722 cases of West Nile virus are reported in 37 states and the District of Columbia, with 33 fatalities.
2008 - 1,356 cases of West Nile virus are reported in 42 states, with 44 fatalities.
2007 - 3,598 cases of West Nile virus are reported in 43 states, with 121 fatalities.
2006 - 4,269 cases of West Nile virus are reported in 43 states and the District of Columbia, with 177 fatalities.
2005 - 3,000 cases of West Nile virus are reported in 42 states, with 119 fatalities.
2004 - 2,535 cases of West Nile Virus are identified in 40 states and the District of Columbia, with 98 fatalities.
2003 - 9,862 cases of West Nile Virus are identified in the US (2,947 in Colorado alone), with 264 fatalities.
2002 - 4,156 confirmed or probable cases of West Nile Virus are reported in 39 states and the District of Columbia, with 284 fatalities. Illinois and Michigan were the most affected with 884 and 614 cases respectively.
1999 to 2001 - 149 cases of West Nile virus human illness in the United States are reported to CDC and confirmed, including 18 fatalities.
1999 - The first cases of West Nile encephalitis in the Western Hemisphere are reported in the Bronx and Queens boroughs of New York.
1937 - The first case of West Nile virus is reported in Uganda. It is common throughout Africa, Central Asia, and the Middle East.
For more information visit the Centers for Disease Control and Prevention's West Nile Virus home page.
About this blog
Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.