MISSISSIPPI STATE -- Confirmed cases of encephalitis and the West Nile Virus in Mississippi have health officials at a state of heightened awareness to the threat of mosquito-borne illnesses.

Dr. Lanny Pace, director of the State Diagnostic Lab in Jackson, told College of Veterinary Medicine faculty members at Mississippi State University in August that it was just a matter of time before the West Nile Virus hits Mississippi. State health officials have been monitoring closely for WNV as well as LaCrosse, St. Louis and Eastern Equine Encephalitis.

In September, health officials confirmed the state's first cases of WNV. Four horses in Lee County have been diagnosed with WNV. Testing is underway on numerous dead blue jays found in the Tupelo area. The virus is typically first detected in bird populations, specifically blue jays and crows.

Dr. Jim Watson, state veterinarian, said while WNV is a concern and is making headlines because it is new to the state, Eastern Equine Encephalitis poses a greater threat to horses. Mosquitoes transmit EEE from wild birds to horses and humans. Horse cases are almost always fatal. Symptoms include unsteadiness, erratic behavior and a notable loss of coordination. Seizures cause death usually within 48 to 72 hours of the first symptoms.

Owners should report horses with suspicious symptoms to veterinarians as soon as possible. Human cases of EEE are rare but often more serious than the other types of encephalitis.

"Unlike West Nile Virus, Eastern Equine Encephalitis is not new to Mississippi. A vaccine is available, but a high number of horses go unvaccinated each year," Watson said. "Vaccines for both have been available this fall, but the West Nile vaccine has been in short supply recently. Most veterinarians should have more in soon."

Watson said more than 40 cases of EEE have been confirmed in the state.

"Eastern Equine Encephalitis is much deadlier to horses, so owners shouldn't forget to vaccinate for this virus as well," he said. "Horse owners should discuss a vaccination program with their local veterinarian to determine the best response to these threats for now and in the coming year."

Dr. Brigid Elchos, the state public health veterinarian, said the Centers for Disease Control supplied most states with additional funds to increase their surveillance for mosquito-borne viruses.

"We are testing blood from people if their physicians suspect encephalitis," Elchos said. "We also are testing dead birds, especially crows and blue jays, for West Nile Virus."

Elchos said WNV typically is first detected in bird populations. Anyone who finds a dead bird, especially a blue jay or crow, should carefully bag it and call the environmentalist at the local health department.

"People should be cautious to avoid mosquito bites all year round, but especially from April through October and at dawn and dusk. Wear mosquito repellants according to label directions and wear long sleeves and long pants whenever out in mosquito-prone areas and times," Elchos said.

"Efforts to eliminate mosquito habitats are very important in controlling these viruses," she said. "Keep grass mowed, and drain standing water around the home where mosquitoes might breed. Keep water for animals as fresh as possible."

For more information, contact: Dr. Lanny Pace (601) 354-6089 or Dr. Jim Watson (888) 646-8731