The Department of Natural Resources and Environmental Control’s (DNREC’s) Mosquito Control Section is again asking the public to help in the state’s surveillance and monitoring efforts for West Nile virus by reporting sick or dead wild birds that may have been stricken or killed by West Nile virus — a mosquito-borne disease of considerable concern to human health and unvaccinated horses.
Mosquito Control requests that the public report only sick or dead crows, blue jays, hawks or owls, or localized clusters of five or more sick or dead wild birds of any species. For dead birds, specimens should appear to have been dead for less than 24 hours and not killed by other obvious causes.
Specimens collected by Mosquito Control will be submitted to the Delaware Public Health Laboratory for virus testing. (Mosquito Control will also operate from early June through mid-October its statewide network of about 20 “sentinel chicken” stations to monitor not only for West Nile virus, but also for eastern equine encephalitis, another mosquito-borne disease affecting humans and horses).
In 2003, there were 17 reported human cases of West Nile disease and 2 human fatalities in Delaware, along with 63 stricken horses. In 2004, there were no reports of West Nile virus in the state in humans or horses, with the drop-off possibly due to relatively cool summer temperatures in 2004 and other natural factors.
“It is difficult to predict what the summer and fall of 2005 hold in store,” said William Meredith, DNREC’s Mosquito Control Section administrator. According to Meredith, since West Nile virus has been in the state for about five years, populations of some bird species such as crows have probably been reduced. It is also likely, said Meredith, that surviving members of other bird species are now more resistant to the virus’ effects and won’t be sickened or die from new exposures. “Nonetheless, Mosquito Control still wants to monitor the targeted bird species for indications of virus,” said Meredith.
Mosquito Control will continue its past practice of documenting all phone reports for the species of interest, but again will not collect and analyze all reported birds because the screening criteria for collecting and testing specimens are often not met. As the season progresses, Mosquito Control will stop analyzing specimens for specific geographic areas once a certain amount of virus-positive birds are found within these specific areas, although the section will continue to solicit the public’s reporting virus-suspect birds for these areas.
“We are interested in when and where West Nile virus might first again appear in Delaware this year and in monitoring the timing and locations of its possible spread throughout Delaware,” said Meredith. “However, we don’t need to collect and analyze every specimen in order to accomplish this, even when the specimens appear very promising for testing. Our sampling strategy this year will be to wisely allocate the number of birds we collect and test between early May and late October, and to concentrate on good representation throughout Delaware to generate the most useful information.
Meredith noted that there is no cause for alarm or fear that uncollected specimens will transmit West Nile virus to humans or pets that might consume a sick bird or its carcass. Dead birds or carcasses can be left to decompose in place, or if aesthetic or other concerns require their removal, they can be disposed of in the garbage after being bagged, or buried. When handling any dead bird killed by any cause, direct human skin contact with the specimen should be avoided by using gloves or a shovel to dispose of the carcass.
Sick or dead birds for the species of interest can be reported to the Mosquito Control Section from Monday through Friday between 8 a.m. and 4 p.m. by call:
New Castle County findings (Glasgow office): (302) 836-2555
Kent or Sussex County findings (Milford office): (302) 422-1512
Calls made after business hours or during weekends or holidays can be recorded on a taped message. Callers should give their name, phone number, address and brief message about the finding. However, the public should be aware that some calls left more than 24 hours before Mosquito Control can review them (usually between Friday evening and Sunday morning) unfortunately usually result in the bird conditions becoming too deteriorated for virus testing.
The Mosquito Control phone numbers above should also be used for citizens to report intolerable numbers of biting mosquitoes. The section uses this information about severe mosquito nuisance situations to help determine when and where to provide control services.