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2002 a Record Year for Hemorrhagic Disease
As reports trickle in from across the U.S., it becomes clear that chronic wasting disease wasn't the only major whitetail health issue of 2002. Bluetongue and epizootic hemorrhagic disease killed thousands of deer.
Although chronic wasting disease dominated the discussion of wildlife health issues in 2002, several viral diseases actually killed far more whitetails. And, the damage was widespread, with researches for the Southeastern Cooperative Wildlife Disease Study finding one or the other of the virus strains in whitetail tissue samples from Georgia north to Pennsylvania and as far west as Texas, Kansas and Wisconsin.
The culprits were well known to deer researchers: epizootic hemorrhagic disease (EHD) and bluetongue (BT). These similar diseases cause high fever and are frequently fatal; infected deer often are found near water sources, where they apparently go in an effort to cool off. BT looks to be confined to the Southeast, while EHD is more widespread.
Both EHD and BT are known to be spread by Culicoides sonnorensis, a species of biting midge. Due to the life cycle of these insects, most outbreaks of the two diseases occur in late summer into autumn, and that appears to have been the case in 2002. The year's earliest virus isolation, from a whitetail in Virginia, came on Aug. 14; the last isolation came from Kansas on Nov. 5. In both of those cases, and in the vast majority of others, the EHDV-2 strain of virus was implicated.
Outbreaks historically have been seen every decade or so in many locations, especially in the eastern half of the U.S. What makes last year's massive 2002 outbreak interesting is that prior to 2002, the most recent major occurrence took place only three years earlier.
| RESEARCHING DEER DISEASES |
Much of the study of diseases affecting whitetails and other wildlife is done by the SCWDS, which is part of the College of Veterinary Medicine at the University of Georgia. Dr. David Stallknecht heads up research of hemorrhagic diseases.
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Drought aids in the life cycle of the Culicoides sonnorensis midge, and dry conditions likely were a factor in both of these most recent outbreaks. However, researchers note that much more study needs to be done to understand all of the variables that control the timing and severity of HD outbreaks.
In the event you find dead deer on your hunting land (particularly during late summer or fall), contact your state wildlife agency. Although the various hemorrhagic diseases seen in whitetails are in some ways similar to Africa's virulent Ebola virus, they do not affect humans.
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