The number of human West Nile virus (WNV) infections have exceeded 2,000 in 2014, according to newly published data from the Centers for Disease Control and Prevention (CDC). This makes it the third year in a row that the United States has seen 2,000 cases or more.


As of December 2, overall, 2,002 cases of West Nile virus disease in people have been reported to CDC. Of these, 1,196 (60%) were classified as neuroinvasive disease (such as meningitis or encephalitis) and 806 (40%) were classified as non-neuroinvasive disease.

Of this total there has been 76 fatalities, or almost 4 percent.

California continues to top all states with 750 cases according to the CDC (California DPH reports 769) accounting for approximately 38 percent of all cases nationally.

In 2013, 2,469 cases were reported with 119 deaths, while in 2012, 5,674 cases were reported with 286 deaths.

First discovered in Uganda in 1937, West Nile virus is a mosquito-borne disease that can cause encephalitis, a brain inflammation.

According to the Centers for Disease Control and Prevention (CDC), approximately 80 percent of people (about 4 out of 5) who are infected with WNV will not show any symptoms at all.

Up to 20 percent of the people who become infected have symptoms such as fever, headache, and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks.

About one in 150 people infected with WNV will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness,vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent.

There is no specific treatment for WNV infection.

WNV is indigenous to Africa, Asia, Europe, Australia and now North America.

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