Evaluated Potential For Passengers To Be Exposed To Rabies

The Centers for Disease Control (CDC) released a report Friday stemming from an incident in August of last year in which a bat was observed on board a commercial airliner shortly after takeoff. While the CDC determined that no one on the plane was exposed to rabies, it did lead to an environmental assessment of the Wisconsin airport where the flight originated.

According to the report, at 6:45 a.m. on August 5, 2011, a commercial airliner carrying 50 passengers, two pilots, and one flight attendant departed Madison, Wisconsin, bound for Atlanta, Georgia. Shortly after takeoff, a bat flew from the rear of the aircraft through the cabin several times before being trapped in the lavatory. The pilots were notified, and the aircraft returned to the airport. All passengers disembarked to allow maintenance crew members to remove the bat from the aircraft. The bat avoided capture and flew out the cabin door, through the airport terminal, and was seen exiting the building through automatic doors. After a search of the aircraft cabin for additional bats, 15 passengers reboarded the aircraft; 35 remaining passengers made alternative arrangements. Because the bat was not captured, the rabies status of the animal was unknown.

The Wisconsin Department of Public Health requested assistance from CDC to conduct a multistate investigation, assessing the potential risk for rabies and the need for rabies postexposure prophylaxis among passengers, the flight crew, and ground crew members associated with the flight. During this investigation, the airline's initial departure manifest could not be provided to public health officials because it was voided when the flight was rescheduled with 15 passengers. Consequently, reservation manifests and airline weight calculations were needed to determine the possible number of persons exposed.

All but five of the people on board the plane were eventually contacted and interviewed. None had physical contact with the bat or exposure to its saliva, and all were alert during the flight.

An assessment of the airport was also conducted after 10 ground crew members reported seeing bats at the facility. Several measures were recommended to minimize the potential for exposure of passengers and airline personnel to bats, including using netting to cover crevices where bats might roost, extending and retracting the jetways at each gate before the first flight of the morning, and training airport employees on correct procedures for bat capture and submission for testing. No more bat sightings have been reported at the airport.

A risk assessment tool was created to evaluate potential contact with the bat or its saliva, rabies vaccination history, and any circumstances during the flight that might have reduced the alertness of passengers and prevented an accurate description of events. The CDC says that even as air travel continues to increase, projected to be 3.3 billion passengers by 2014, transmission of infectious diseases before, during, and after a flight is an increasingly important public health concern. Transportation of animals, including exotic species, on aircraft has the theoretic potential for transmission of zoonotic pathogens. However, no air travel–associated zoonotic outbreaks resulting from direct animal-to-human transmission have been reported.

FMI: www.cdc.gov, www.dhs.wisconsin.gov