AIKEN - The West Nile virus has hit Aiken County, and horses are among the first victims.
One dead bird and four horses, at least two of which had to be euthanized, have fallen victim to the mosquito-borne virus, according to the South Carolina Department of Health and Environmental Control.
The good news is that veterinarians recently learned that vaccines are more effective than once thought, providing protection for as much as 94 percent of the inoculated horse population.
Dr. Arthur Wozniak, the director of DHEC's diagnostic microbiology division, said the recent instances in Aiken County were discovered during the middle of this month, but other county cases date to October.
West Nile was first confirmed among horses in the state in September. Since then, 14 horses have tested positive - compared with about 50 in Georgia.
Nancy Jowers owned two of the Aiken horses that were bitten by infected mosquitoes. The symptoms hit the horses quickly, and in about a week she knew there was no hope.
In contrast to the speed of the virus, testing for West Nile on horses can take up to 10 days.
"I didn't even know there was a vaccination for West Nile until about three weeks prior to their being sick," Ms. Jowers said.
A neighbor, Annie Fields, said her horses recently began receiving inoculations, though they show no signs of sickness. She said it will take several more weeks for them to build their immunity.
Tony Caver of Clemson University's research lab in Columbia, which tests for West Nile and other horse illnesses, said he believes the instances are underreported. He said case numbers might grow as more test results come back.
"Horses show a wide range of symptoms, from no problem whatsoever to stumbling, to lack of coordination, to weakness in the hind limbs, to paralysis," Dr. Caver said.
He said the onset of cold weather and lack of rain can ease West Nile occurrences, but preventive measures and routine inoculations are still needed.
Reducing standing water and limiting horses' outdoor exposure at dawn and dusk can help prevent the dangerous mosquito bites, he said.
Although testing is encouraged for animals displaying symptoms, Dr. Caver said the owners will end up paying for the test results now that the virus has been reclassified as endemic, meaning it has become prevalent in the region.
DHEC, which tests dead birds for West Nile, is not accepting any more of those samples for the year.
Aiken County has not had any confirmed cases of humans contracting West Nile.
Reach Eric Williamson at (803) 279-6895 or firstname.lastname@example.org.