University of Florida Veterinarian Troubleshoots West Nile Virus

In 2001, University of Florida veterinarian Maureen Long, DVM, PhD, Dipl. ACVIM, became an authority on West Nile virus by accident. That year, Long and other UF Large Animal Medicine clinicians saw some of the first Florida horses breaking with the mosquito-borne disease.

Prior to its arrival in Florida, there had been fewer than 100 cases of the disease diagnosed in the United States. But that year more than 500 horses would break with the disease in Florida and the clinic admitted over 10% of these reported cases. Intrigued, Long and her colleagues put together a proposal that was funded by the Pari-Mutuel Wagering Trust Fund in Florida to study the disease outbreak. The next year, 14,000 cases of West Nile virus were diagnosed in horses and the demand for Long's clinical expertise kept her crisscrossing the country, making her a national authority by the end of the year. This initial grant led to several more successfully funded projects. In just a few short years, UF has become a leader in West Nile virus research in horses. Long and her colleague, veterinary virologist Paul Gibbs, BVSc, PhD, FRCVS, had the opportunity to study a new modified West Nile virus vaccine in horses with potential human application.

"Infection in horses is important because it's an indication of what people might face with the virus. Immunity in horses provides a proxy for understanding the virus in humans especially children and the elderly." –Dr. Maureen Long
"Vaccines like the one we studied were developed as the second generation of products for enhanced and long duration of protection," Long added.

West Nile virus and other mosquito-borne viruses cause encephalitis, both in horses and people, adding a human component to Long's research. The virus affects the central nervous system and symptoms can range from fever to paralysis and death.

"Infection in horses is important because it's an indication of what people might face with the virus," Long said. "Immunity in horses provides a proxy for understanding the virus in humans especially children and the elderly."

Lately, Long's research has continued on a "translational course" with a goal to transform the services the College of Veterinary Medicine offers while developing cutting-edge research for new detection methods and treatment options for humans and horses affected by disease. Long offers both standard serum and molecular diagnostic testing for several causes of encephalitis in animals including West Nile virus, Eastern equine encephalitis virus and herpesviruses. The latter test capability was developed directly as a result of the 2006/2007 outbreak of neurological herpesvirus in horses in Wellington, Fla., that virtually shut-down the industry.

"The development of new molecular strategies for detection of the equine encephalitides provides the only Florida based rapid test site for these diseases. We frequently receive samples from horse venues throughout the state that require answers within hours; we have built a program around the latest technology and talent personnel that have the agility to provide rapid answers. This allows these horse activities to continue unhindered; in the past, activities have been halted at peril to the industry, while awaiting results from labs that were out-of-state."

On the research-side, Long and her graduate students are involved in cutting-edge projects utilizing research techniques that span the globe from geography to molecular biology. For surveillance, one project collaborates with geographers to use geographical information systems based on satellite images to track emerging disease.

On the cellular side, gene chip technologies are being applied to examine the mechanisms of diseases that specifically affect the equine brain.

"Understanding the complex mechanisms at the cellular level will assist us in developing medications that will directly treat viruses and parasites that infect the brain of horses, and of course people and other animals," Long said.--Cindy Spence

Reprinted with permission of Florida Veterinarian, publication for the University of Florida College of Veterinary Medicine. Visit for more information.

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