Alligators Found to Transmit West Nile Virus

BOISE, Idaho, November 13, 2003 (ENS) - Health officials from Idaho to Louisiana are reporting that West Nile virus is being transmitted from alligators to humans.

The Louisiana State University Veterinary Diagnostic Laboratory has confirmed West Nile Virus infections in farm raised alligators from three farms in Louisiana this year. In 2002, similar findings occurred on alligator farms in Georgia and Florida.

These alligator farms are not considered a public health threat, Louisiana officials say, since humans have a "minimal risk of catching West Nile from alligators." Mosquitoes still are considered the primary vector for spreading the virus to humans.

But on November 6, Idaho state laboratory results identified Idaho’s first probable human case of West Nile virus infection in a man who works with a Twin Falls County alligator farm. His only known exposure to the virus came when he worked with sick alligators later determined to be carrying the virus.

Lab tests conducted at the Idaho Department of Health and Welfare’s Bureau of Laboratories were positive for West Nile virus, but health officials say the man, in his 40s, has completely recovered from the infection and poses no health threat to other Idaho residents.

Idaho health officials have not determined how the man picked up the virus. They said he does not recall being bitten by mosquitoes, by far the most common way in which humans pick up the disease.

But his recent work involved using bare hands to handle ill juvenile alligators that later were identified as carrying the virus.

Alligators, like these in a Florida facility, can transmit West Nile virus to humans, researchers have found. (Photo courtesy Roy Peters)

Idaho officials from the departments of Health and Welfare, Agriculture and South Central District Health are working with the farm operator to assure public safety.

The farmer voluntarily had the remaining alligators humanely destroyed and safely disposed of, under guidance from the wildlife section of the Idaho Department of Agriculture. Following recommendations from South Central District Health officials, the farmer also has disinfected the enclosed building where the infected alligators were being raised.

Peter Brazaitis, former curator of animals at the Central Park Zoo in New York City and the superintendent of reptiles at the New York Zoological Park/Bronx Zoo, reported to the International Society for Infectious Diseases on conditions in Louisiana alligator farms that appear to be spreading the disease.

"There are now a great many cases of West Nile virus among alligator farmers, workers, and especially captive farmed alligators," said Brazaitis. "To save money on heating water, the farmers have gone to only cleaning their tanks once a week and are overcrowding the tanks by three times or more capacity. The tanks are breeding grounds for mosquitoes, filthy, and badly contaminated with decaying food and feces."

"Worse," said Brazaitis, "they are taking infected animals and releasing them back into the wild. We are talking 10s of thousands of animals on these farms."

Brazaitis explained that mosquitoes are transmitting West Nile virus between animals and people.

"The state does not enforce or inspect as they did in the past for fear of law suits. Farmers fear that a finding of contamination on the farms may result in their getting closed down. Thus, they will not allow inspections and threaten to sue the state if they do and they lose revenue because of it."

"As the alligator farmers and their taxes are a big source of revenue to the state management program, and farmers are pretty much running the state program, the state does not want to rock the farmers' boat," Brazaitis said.