West Nile Virus
West Nile virus 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 who are infected 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
- West Nile Virus Fact Sheet Fact Sheet | Spanish
- CDC Fact Sheet English
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
- School/Childcare Guidance and Communicable Disease Guide
- Communicable Disease Guide for Schools and Child Care Settings
- Fight The Bite! (CDPH)
- How to Properly Apply Mosquito Repellant (CCMVC)
- Protect Yourself from West Nile virus (Contra Costa Health Services)
- The Buzz about West Nile Virus PSA (CDC) English | Spanish
- West Nile Virus Disease Webpage (CDPH)
- West Nile Virus Homepage (CDC)
- Contra Costa West Nile Virus Activity (CCMVC)
- Latest West Nile Activity in California (CDPH)
- Map: West Nile ArboNET Outbreak Maps (US Geological Survey)
- West Nile Virus Detected in First Mosquitoes of 2015 in Contra Costa County – Contra Costa Mosquito & Vector Control News Release – June 17, 2015