West Nile Virus & Dead Birds

by Doug Taylor

West Nile Virus is usually a disease which birds (primary host) get from the bite of a carrier mosquito (in Michigan the CULIX species is the major carrier). Occasionally horses and humans (dead-end hosts) are also bitten by these mosquitoes and contract the disease. Over 160 species of birds worldwide have been discovered with the disease which is said to have originated in central Africa and brought to the U.S. in a ship’s cargo hold. Certain birds are more susceptible to West Nile Virus and thus when they die from the disease their death becomes an early warning beacon to humans about the presence of the carrier mosquito.

So when these several species of dead bids are found with no apparent cause of death (with no trauma of, say, a crash into a car or window, a mauling by a cat or being shot), public health departments want to obtain the bodies of these birds to analyze them for the presence of West Nile Virus.

NOTE: Not all dead birds of these species which die of natural causes have the virus. And of course  well-preserved bird specimens are needed for analysis.

So what bird species are most susceptible to and therefore most likely to contract West Nile Virus? Crows, ravins and blue jays … so says Harlan Hays, a graduate student at the University of Michigan School of Public Health assigned to the Livingston County Public Health Department, Environmental Health Division. Mr. Hays’ total focus this summer is the West Nile Virus. Other bird species, such as starlings and grackles, can contract the disease, but they have a higher resistance level than the three “marker” species and thus their deaths are not as good in providing early warning.

And what is a concerned home-owner to do if he/she finds one of these three bird species dead (and well preserved with very little decomposition) in his/her yard?

-         get some sort of plastic bag into which you will place the bird

-         turn the bag inside out with your hand inside the reversed bag

-         pick the dead bird up, using the bagged hand

-         with your other hand, pull the bag over the bird’s body (the bag will now be original side out and the bird will be inside)

-         secure the open end of the bag with some sort of tie

-         place the bagged bird on ice

-         then bring the bird to the Livingston County Health Department at the corner of Chilson Road and Grand River – West Complex.

In certain circumstances the Public Health Department will make arrangements to pick-up the specimen – call first (517) 546-9850 ext. 509. 

Mr. Hays points out that humans will not contract West Nile Virus by simply handling an infected bird. The virus must have a means of direct entry to the human blood stream, i.e. a mosquito bite (by far the most common means), infected blood transfusions (blood is now being screened for WNV) or remotely possible through a deep skin cut which comes in contact with the infected bird.

For more information about West Nile Virus and to see maps by zip codes where birds have been tested and where positive results have been found, log onto www.michigan.gov/westnilevirus.

NOTE: This site is also available for reporting the finding of a dead bird of any species which has died without signs of a traumatic death.

Last modified: 12/05/03 16:58:26 -0800