Frequently Asked Questions

West Nile Virus (WNV) is a mosquito-borne disease that is common in Africa, West Asia and the Middle East. For more information please call 530-265-1222.

WNV was first detected in the United States in New York in 1999. Since then, WNV has rapidly spread across the U.S., reaching as far west as California and Washington. For more information please call 530-265-1222.

In 2002, California's first reported case of West Nile Virus was recorded in Los Angeles County. For more information please call 530-265-1222.

People usually get West Nile Virus from the bite of an infected mosquito. Also, there is evidence that WNV can be acquired via a blood transfusion or organ transplant from an infected donor. For more information please call 530-265-1222.

Most people who are bitten by a mosquito with WNV will not get sick. People who do become ill may experience mild flu-like symptoms like fever, headache and body ache. It is estimated that less than 1 percent of the people who are infected with WNV become severely ill and require hospitalization. The elderly are particularly susceptible to illness caused by WNV.

Currently, there is no specific treatment for WNV infection. Since it is a virus, it does not respond to antibiotics. In severe cases, hospitalization and supportive care is important. If you have symptoms of West Nile Virus, call your doctor. For more information please call 530-265-1222.

Avoid activity outside when mosquitoes are most active, especially at dawn and dusk. When outdoors, wear long pants, long sleeve shirts and other protective clothing. Apply insect repellent according to label instructions. Make sure that doors and windows have tight fitting screens. Repair or replace screens that have tears or holes. Eliminate all sources of standing water that can support mosquito breeding. For more information please call 530-265-1222.

California has a long history of conducting surveillance for mosquito-borne viruses and has taken active steps to ensure early detection of WNV. Due to ongoing collaboration with over 70 local mosquito and vector control agencies and state public agencies, California is well prepared to detect and monitor WNV. These agencies use a variety of scientific techniques and products to control mosquitoes in their earliest stages and play a key role in reducing the risk of WNV. Also, California has launched a statewide public education effort concerning personal protection measures, mosquito source reduction and reporting dead birds. For more information please call 530-265-1222.

The public is encouraged to assist in the efforts to detect and monitor WNV by calling the WNV hotline if they find a crow, raven, magpie, jay or hawk that has been dead for about a day. Birds play an important role in maintaining and spreading this virus. Mosquitoes acquire the virus from infected birds, and then transmit the virus to people. Evidence of the virus in dead birds is often the first indication that WNV has been introduced into a new region. The California Department of Health Services has set up a toll free hotline for the public to report dead birds: 877-WNV-BIRD. Birds can also be reported by visiting the West Nile Virus Information site.