|West Nile Virus Information|
To: NJ Large Animal Practitioners
I am sure you are all aware of the return of West Nile Virus to the region. Attached is the most recent report from the USDA WNV coordinator, Dr. Randall Crom, summarizing positive results. The first positive mosquito pools have been identified this year, indicating increased circulation of the virus in the environment. The potential for human and equine infection increases as this cycle continues. Although recommendations for protective measures have not been altered as a result of virus isolation, ongoing efforts in each county to reduce the mosquitoes' habitats are being enhanced. Individual home and farm owners should be encouraged to eliminate standing water on their property. Mosquito repellents are of limited use on horses, but are recommended for human use.
Clients with dead crows or other birds should be directed to their local health departments for assistance with sample submission. Gloves should be worn when handling avian specimens to minimize health risks from any organisms present. Handling equine specimens from suspect cases poses almost no risk of infection from WNV, but since other zoonotic agents, including rabies, may be present, adequate safeguards should be utilized.
The Division of Animal Health recommends that you include WNV in your differential diagnosis in any horse exhibiting neurological signs until after the first frost. As with the other encephalitis viruses, report your suspicions to the Division of Animal Health immediately [609-292-3965]. Initial serum samples should be submitted followed by convalescent samples and submissions of brain tissue for virus isolation when indicated [samples sent on ice]. It is imperative that suspect equine cases resulting in death are evaluated for WNV, EEE, WEE and rabies. Therefore, brain tissue must be submitted. If you need assistance in the transport of these specimens, contact the Division.
We are also approaching the time of year that EEE is identified in mosquito populations in NJ. Although we had no equine cases of EEE in 1999, we usually see at least a few equine cases every year. Therefore, recommendations for vaccination against EEE and WEE should continue. A vaccine for WNV was conditionally-approved by the USDA in August 2001 for use by licensed veterinarians.
Should you have questions about this or any other matter, please call.