Early experience with West Nile virus in New York demonstrated that corvids (crows and blue jays) were more sensitive to the virus than other avian species, and more likely to die as a result of their infection. Monitoring death amongst these birds can be an early indicator of virus activity in an area. In 2001, a toll-free hot line was established for citizens to report dead crows. Information was collected as to the location and condition of these birds, and appropriate birds were collected for testing. As a result of this effort, WNV was first detected in Michigan in August 2001, in dead crows. There were 65 WNV-positive birds detected in 10 counties in the southern portion of the Lower Peninsula. This surveillance system was continued in 2002, and positive birds were detected in 73 of Michigan's 83 counties.

In 2003, a system for web-based reporting of dead birds was developed. During 2003 surveillance 89 corvids tested positive from 75 zip codes located in 33 counties. It was highly successful and will continue to be used this year. This system will again allow for rapid reporting of dead bird sightings. Calculations of the number of dead birds per square mile in a county can also be used to estimate the level of risk for human infection in an area. Communities can use this information to target their intervention and prevention strategies to areas where WNV activity is high.

Visit the Testing, Tables and Maps Section for up-to-date surveillance data.