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is not directly contagious; it needs to be spread through the bite of one of these flies. Once the fly bites an infected animal, the virus can reproduce inside the insect. The insect then is able to transmit even more virus particles than it picked up in the first place.
As cooler weather prevails, the activity and the survival of the vector will diminish. The number of new cases submitted to the ADRDL has declined; whether this is due to decreased transmission or to a better awareness of disease features in the field is unclear. 

Q. How is EHD diagnosed in an animal?
A. A definite diagnosis consists of demonstrating the EHD virus in the blood of an animal with clinical signs. Indirectly, antibodies against EHD can be detected in the blood. This indicates that the animal has been exposed to the virus at some time, but doesn't necessarily confirm that EHD is the cause of the current illness in the animal. We know from past investigations that some normal cattle have evidence of EHD antibodies, meaning they were exposed to the virus, but have never shown any signs of illness.

Q. How many herds are affected by this outbreak?
A. As of October 2, veterinarians have submitted samples from 51 different cattle herds with EHD signs. Of these 51, 32 of these herds have evidence of EHD virus infection, 12 have had negative results, with tests pending on the rest. The number of submissions to the ADRDL likely vastly underestimates the total number of herds affected. We have heard from many veterinarians in the outbreak area that there are many more herds experiencing clinical illness than were submitted to the laboratory. An effort is underway to interview veterinarians and producers to get an idea of how many herds might have been affected.

Q. Where are the affected herds?
A. According to ADRDL submissions only, herds have been identified as far west as Gregory County, as far east as Turner County, and as far north as Sanborn County. It is very possible that herds outside that area have been affected.

Q. What should a cattle producer do if he or she suspects EHD in some of his cattle?
A. Contact their veterinarian. They may wish to collect samples for diagnosis and can advise about treatment and management of affected animals. In general, pro

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