No bat infestation at Madison airport

MILWAUKEE — Federal and state investigators found no evidence to substantiate reports of a bat infestation at the Madison airport and have closed their investigation, officials said Thursday.

The inquiry followed an Aug. 5 incident in which a bat made its way onto a Delta flight from Madison to Atlanta. Authorities interviewed baggage handlers in Madison afterward who reported seeing live bats in the area as well as dead bats on the ground. Their comments raised concerns that a colony had taken up residence at the airport.

However, investigators found nothing to support either report.

“There was no evidence of a bat infestation,” Danielle Buttke, a spokeswoman for the Centers for Disease Control and Prevention, told The Associated Press. “At this point it appears this was an isolated incident.”

The Delta flight was bound for Atlanta but returned to Madison after the winged intruder emerged. A YouTube video showed the bat flitting around the plane’s cabin. Passengers trapped the animal in a jet bathroom, but after the plane landed it eventually escaped.

Health officials have since tried to track down all 50 passengers to ask about possible exposure. Buttke said 45 passengers had been reached as of Thursday, and none had a level of contact with the wayward bat that would require a rabies vaccination as a precautionary measure.

She said the CDC was still trying to track down the other five passengers.

Jim Kazmierczak, the state public health veterinarian with Wisconsin’s Division of Public Health, helped lead the investigation at the Dane County Regional Airport. He said officials had scoured the airport grounds but found neither bat droppings nor urine stains, two telltale signs of a bat infestation.

Airport spokesman Brent McHenry said officials there keep meticulous records of all animals spotted around runways and the terminal. The records did list five dead bats, but he said those reports spanned at least five years.

“We don’t know what (the baggage handlers) were referring to,” he said. “We’re confident there’s no challenge with any sort of wildlife inside Dane County Regional Airport facilities.”

The CDC had previously noted that bats sometimes congregate in short-term colonies comprised of mothers who had given birth. When asked whether it was possible that such a colony had taken up temporary residence but dispersed by the time the investigation began, Buttke said it wasn’t likely.

Besides leaving droppings, she said, bats have oil in their skin and fur that leaves obvious stains on walls and crevices when they roost. Investigators didn’t see any such stains, she said.

Despite the lack of evidence, Kazmierczak said he wasn’t surprised that baggage handlers reported seeing live bats. The airport is in a somewhat rural area and has conditions that bats find favorable, he noted.

“They’re pretty ubiquitous critters,” he said. “Any time you have an open area next to woods or wetlands you’re going to have bats.”