The California Department of Public Health (CDPH) has recorded an additional 46 human West Nile virus (WNV) cases during the past week, bringing the state’s total for 2014 to 608.

West Nile virus
Culex quinquefasciatus

Los Angeles County accounted for more than half the cases this past week with 24. Other counties reporting cases include Colusa (1), Kern (1), Orange (14), Placer (2), San Diego (1), Stanislaus (2), and Yolo (1).

Three additional WNV fatalities bring California’s total to 20.

West Nile virus is a mosquito-borne disease that can cause encephalitis, a brain inflammation. West Nile virus was first detected in North America in 1999 in New York. Prior to that it had only been found in Africa, Eastern Europe, and West Asia.

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. For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page