Susan Buckley, RN, Director, Public Health
Ira Singh, MPH, Deputy Director
Donald I. Baird, MD, Health Officer

Division of Environmental Health


Date Released: 6/10/2004
Subject: Southern California reports first human West Nile Virus case for 2004
Contact: Brent Whitener, Vector Control Officer, Environmental Health Division
Phone: (707) 445-6215

A San Bernardino County woman was confirmed as infected with West Nile Virus on Monday, according to the California Department of Health Services. She is reported to have completely recovered. The virus, carried by infected birds and transmitted by a mosquito bite, has been moving westward across the U.S. since it was first identified in New York City in 1999. State health and mosquito control officials tracked the entry of West Nile into the southern California deserts last August. The southern California woman joins patients in New Mexico, Arizona and North Dakota as the initial human cases of the disease in 2004. Some 10,000 human cases of West Nile Virus were reported nationwide during 2003. State health officials will carefully watch the northward movement of the virus this year. The birds tested positive in California this year thus far have been found in southern California.

West Nile Virus is new to California, but mosquito borne diseases are not. Several diseases such as Saint Louis Encephalitis have required a comprehensive statewide surveillance system to track mosquito borne diseases. With the recent arrival of West Nile, the system is working well, helping officials understand and predict the possible impacts of the disease as it moves through the state.

Last year the state of Colorado was especially hard hit by the effects of West Nile Virus, and health officials there are sharing vital information about the impacts of the disease. Eleven human cases were reported as the virus entered Colorado in late 2002, but that number had increased to about 2,950 human cases at the end of 2003. Colorado health officials confirmed that a small percentage (about 1%) of human cases involve encephalitis or similar neurological disease. This very serious condition involves swelling of tissues around the brain, and requires hospitalization.

The majority of patients with West Nile Fever experience symptoms that often persist from five to twenty days. These symptoms include a fever of over 100 F., muscle soreness, tremors, severe and prolonged headache, and a lethargic “run down” feeling. Although encephalitis requires in-patient care, West Nile Fever is treated with supportive care, often while the patient remains at home. Humans are dead end hosts, and cannot pass the disease on to others if infected and bitten by a mosquito. Health officials nationwide caution that patients with any symptoms that persist over five days should see their physician or medical provider.

The Environmental Health Division is urging people to reduce mosquito breeding sources near their homes by emptying the water from any possible mosquito breeding sources such as flower basins, boats and boat covers, unused wading pools, or old tires that may be on their property, and replacing or repairing missing or defective window screens. People can also protect themselves from biting insects by avoiding activities at dawn and dusk, wearing long sleeves and pants in mosquito prone areas, and applying over-the-counter repellants containing the active ingredient DEET. Residents planning travel outside the Humboldt County should take the same precautions in areas affected by West Nile elsewhere in California and the U.S.

Individuals or groups with questions about mosquito control or West Nile Virus are encouraged to contact Brent Whitener at the Environmental Health Division’s Vector Control Desk at (707) 268-2203 or toll free at 1-800-963-9241. A newly established local web site at contains West Nile Virus information directly relating to Humboldt County and will be regularly updated. The California State West Nile web site at includes general information about the disease as well as updates and maps showing virus activity statewide.


« Back

County Home | Health & Human Services Home | Administration | Mental Health | Public Health | Social Services