Aircraft cabins do not help spread infectious diseases, says report

It is only natural for one to assume that being inside an aircraft full of people could be an easy way to catch an infectious disease. But that assumption is wrong since the quality and quantity of filtered air inside the cabin of a modern aircraft is in fact far better than in other crowded places, a survey of data by the Australian Transport Safety Bureau (ATSB) has revealed.

The Australian Transport Safety Bureau is an operationally independent body within the Australian Government’s Department of Infrastructure, Transport, Regional Development and Local Government. It is also Australia’s prime agency for investigations into transport safety.

There have been cases of infectious diseases being transmitted in-flight, but the report says that those transmissions were probably caused by crowding in a confined space and not because of cabin conditions.

The health of a passenger is put at risk only when circulation and filtration systems do not work properly, the study said, and suggested that actually airports do offer more chances for the spread of infection than do aircraft.

The ATSB admitted that the increase in international air travel has enhanced the risk of infectious diseases spreading globally, and urged the aviation industry to play a role in dealing with that risk.

The Australian Transport Safety Bureau said “it conducted the study because of public concern about whether, or to what extent, aircraft cabins increased risk of transmission of infectious disease, and also reviewed current literature on the potential risk.”

The report concluded: “Despite the popular view that the risk of contracting an infectious disease during air travel is high, the available evidence suggests otherwise. Many passengers might be concerned that the high recirculation rates of cabin air on modern aircraft poses a particular risk for infection. However, outside air entering an aircraft cabin at altitude is essentially sterile, and the high airflow rates, laminar airflow pattern and frequent air exchanges of an aircraft cabin ventilation system minimises the spread of infection on board aircraft.”

The study came across the fact that filtration systems on modern aircraft should in fact remove the possibility of the transmission of infection.

Taking into account the fact that such a large number of flights are occurring each day across the world, reported cases of transmission of infection in an aircraft cabin have happened relatively infrequently, the report said, adding: “The evidence suggests that a passenger’s health is not greatly at risk through air travel and widespread infections are unlikely.”

And, even when transmission of an infectious disease was reported to have occurred in an aircraft cabin, the transmission of infection was caused owing to close contact with an infected passenger. “This fact suggests that the risk of transmission within an aircraft cabin is no greater than in other crowded and confined spaces, provided circulation and filtration systems are working properly,” the report by the Australian Transport Safety Bureau stressed.

It also brought to light the fact that though the increase in international air travel could facilitate the spread of an influenza pandemic in future, the aviation industry would be playing a critical role in easing the impact of such a pandemic.

“Australia,” the report promised, “will prevent or minimise the spread of an emerging pandemic through border control measures and also possibly through travel restrictions.”

However, the report warns passengers that “though the overall risk of transmission of infection in an aircraft cabin is low, passengers need to give sufficient thought to their fitness to fly –not only for their own health but also for that of the other passengers who will be travelling along with them.”

The Australian Transport Safety Bureau recommended in the report that information to help passengers make “more responsible decisions” on whether or not to travel could be given more prominence.