|West Nile Virus Information|
New Jersey Department of Agriculture
To: Equine and Large Animal Practitioners
Re: West Nile Virus (WNV) Update
Although mosquito season is not yet upon us, the Department of Agriculture is getting ready for another West Nile Virus (WNV) season. As you may know, in 2001 there were more than 600 cases of WNV reported nationwide including 30 cases and 13 deaths in New Jersey. More than 400 of the nation's cases were in Florida where there are still active cases. Because many New Jersey horses spend time in Florida they may be particularly at risk of exposure and illness.
Since WNV is now considered endemic in this country, additional cases can be expected in New Jersey in 2002, depending on the extent and success of vaccination. Vaccine efficacy studies have not yet been completed, but current evidence suggests that horses should be vaccinated with both doses of the vaccine at least three weeks prior to mosquito exposure. Annual vaccination following the initial series should also be completed three weeks prior to exposure.
Any suspect cases should be treated according to previously issued guidelines. All neurologic cases should be reported to the Division of Animal Health as soon as possible. Please complete the neurologic disease worksheet on these horses, or we can go through the worksheet when you call in to report the case. Vaccination history and travel history are extremely important. For all cases serum is the fastest way to test for a battery of neurologic diseases, including WNV, EEE, and EHV.
For all terminal cases, please collect brain tissue. Try to encourage owners to use a carcass transporter (see list below) so that brain tissue can be easily retrieved. Otherwise, try to collect the brain (or head) on site, if possible. In acute terminal cases of WNV, brain tissue may be the only positive sample. (Because rabies is always a potential etiology for all fatal neurologic cases in New Jersey, all samples are first tested for rabies virus.)
We have established a contact system to provide for weekend reporting of suspect cases. We will have a name and contact number for you to call on the office answering machine (609-292-3965). The individual on call will retrieve messages you leave in a timely fashion.
Please call with any questions, concerns or suggestions you have regarding these or other issues.