West Nile Virus

Tracking West Nile Virus

Surveillance

The surveillance program conducted by MCVNC is three-fold and covers dead corvids, adult mosquitoes and sentinel chickens.

Dead Corvids: Surveillance for dead corvids involves reports from the public of dead crow, jays and their kin. Birds that have been dead for less than 24 hours can be reported to MCVNC on the Dead Bird Report Form or by calling (503) 988-3464. If they meet the criteria employees will come out and pick up the carcasses and submit them for West Nile testing. Check the bird identification page for photos of regional corvids.

Adult mosquitoes: MCVNC routinely sets traps to collect adult mosquitoes. Once trapped the mosquitoes are pooled into samples of the same species and submitted for testing for West Nile virus, St. Louis encephalitis and Western Equine Encephalomyelitis.

Sentinel chickens: Four flocks of sentinel chickens are also located in Multnomah County. The chickens are tested every other week to determine if West Nile virus is being transmitted in the area.

National West Nile virus tracking: The Center for Disease for Control and the USGS track West Nile virus cases. For more information, see:
http://www.cdc.gov/ncidod/dvbid/westnile/
http://diseasemaps.usgs.gov/

Control

Control of mosquitoes can focus on either larvae (immatures) or adults. To view a comprehensive guideline for mosquito control for West Nile virus, see Mosquito Control Guidelines for WNV 2007 (PDF - ~140 KB). For more general information on mosquito control, follow this link. When WNV is detected in the county and if the number of adults trapped in the areas where the virus is found reach a certain level adult control may be initiated. The product used and the method of application would depend on the circumstances.

Education

The County employs a full-time health educator to provide workshops and presentations to the community. To connect with Kari Lyons, e-mail lyonsk@co.multnomah.or.us or call 503-988-3400 ext. 25860.

Page updated March 05, 2008