West Nile Virus
West Nile virus (WNV) is an infection of birds that is transmitted by mosquitoes. Occasionally, humans and animals are infected when bitten by an infected mosquito. West Nile virus tends to be seasonal, beginning in the early summer and continuing through fall. In humans, most infections, 70-80% infections result in no symptoms. About 20-30% of persons who are infected will have symptoms that may include fever, headache, rash, nausea, vomiting and body ache. Less than 1% of persons will have severe illness and while rare, it can be fatal for the elderly and people with compromised immune systems.
What You Can Do:
- Protect your home & garden from mosquito breeding and use insect repellents when outside.
- Report dead birds and squirrels to monitor West Nile Virus activity. To report a dead bird or squirrel in California, complete a web-based form or call 1-877-968-2473.
- Report neglected (green) swimming pools to Contra Costa Mosquito & Vector Control, complete a web-based report or call 925-771-6196. Free mosquitofish can be requested. Neglected pools, ponds, and troughs produce mosquitoes putting you and your family at high risk for West Nile virus.
About West Nile Virus
To learn more about mosquito prevention
- Contra Costa Mosquito & Vector Control District
- Are you Raising Mosquitoes? – Home & Garden Checklist (CCMVC) English | Spanish
- Protect Your Family - Use a Repellent (CDPR) English | Spanish
- Protecting Outdoor Workers (CDPR) English | Spanish
- Fight The Bite! (CDPH)
- Protect Yourself from West Nile virus (Contra Costa Health Services)
- The Buzz about West Nile Virus PSA (CDC) English | Spanish
- Contra Costa West Nile Virus Activity 2014
- West Nile Virus Disease (CDPH)
- West Nile Virus (CDC)
- Latest West Nile Activity in California
- Map: West Nile ArboNET Outbreak Maps (US Geological Survey)
- First Dead Bird Tested this Year is West Nile Virus Positive in Contra Costa County – Contra Costa Mosquito & Vector Control - 4/25/2014
- More West Nile Virus Activity in Discovery Bay and Now Alamo – Contra Costa Mosquito & Vector Control - 7/18/2013