AUBURN – Two Placer County residents have tested positive for West Nile virus (WNV), the first in the county in 2007, Dr. Richard Burton, County Public Health Director, announced today. Both individuals, a man and a woman, are recovering at home. The individuals who contracted the disease live in Loomis and Granite Bay.
Dr. Burton emphasizes that the risk to humans is low. The virus is transmitted by the bite of an infected mosquito. Most individuals who are infected with WNV will not experience any illness. Approximately 10 percent to 15 percent of infected individuals will have only mild symptoms, such as fever, headache, fatigue, and joint and body aches, muscle weakness and rash. In less than 1 percent of infected individuals, the virus causes neurological illness, including inflammation of the brain and may cause additional symptoms of neck pain or stiffness, difficulty concentrating, vomiting, diarrhea, and sensitivity to light. Anyone with the above signs and symptoms is advised to seek medical care. Most individuals who are infected with WNV will not experience any illness. Individuals 50 years of age and older have a higher chance of getting sick and are more likely to develop serious symptoms when infected with WNV. Recent data also indicate that those with diabetes and/or hypertension are at greatest risk for serious illness.
"We know that West Nile virus is established in Placer County," Dr. Burton said. "Late summer is typically when we've seen an increase in West Nile activity, including human cases. There are simple precautions that residents and visitors should take to prevent getting bitten by an infected mosquito."
Dr. Burton reminds Placer County residents of three simple ways to protect themselves from WNV:
- DEET – Apply inspect repellent containing DEET, picaradin or oil of lemon eucalyptus. Repellents keep the mosquitoes from biting you. DEET can be used safely on infants and children 2 months of age and older. Follow instructions carefully.
- DAWN AND DUSK – Mosquitoes that carry WNV bite in the early morning and evening so avoid outside activity at this time or be sure to wear repellent and long pants, long sleeve shirts and other protective clothing. Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes.
- DRAIN – Mosquitoes lay their eggs on standing water. Eliminate all sources of standing water on your property, including flower pots, old car tires, rain gutters and pet bowls. If you have a pond, use mosquito fish or commercially available products to eliminate mosquito larvae. Contact your local mosquito and vector control agency if there is a significant mosquito problem where you live or work.
To date this year 12 birds, 21 mosquitoes, and 3 sentinel chickens have tested positive for WNV in Placer County. Tests on horses and squirrels have been negative. WNV is transmitted to humans and animals through a mosquito bite from a mosquito that has been infected by feeding on an infected bird.
Statewide, there have been 200 human cases so far this year in 24 of the state's 58 counties. There have been 832 positive dead birds; 819 mosquito pools; 231 sentinel chickens; 19 horses; and 11 squirrels.
For more information about WNV, visit www.westnile.ca.gov. In addition to reporting all dead birds, Placer County residents are encouraged to report dead tree squirrels. The Web site includes information on the most common birds found with WNV. Dead birds and squirrels can be reported on the Web site or by calling (877) 968-2473.