Plane speaking: airports a hotbed of infectious diseases
From security trays to infected passengers on aircraft, flying puts us at risk of contracting a host of respiratory viruses
“Plastic security trays, which we all have to handle, were found to have the highest concentration of viruses.” Photograph: iStock
Fingers crossed – early indications are that this won’t be an especially virulent flu season. But there are plenty of other seasonal bugs whose prevalence peaks in the coming months. They enjoy near perfect conditions for transmission as we huddle together on trains and buses, sneezing and coughing helplessly.
The increasingly cramped conditions in economy-class air travel are also bug-friendly. And according to recent research, airports have their own infection challenges.
Researchers from the University of Nottingham and the Finnish National Institute for Health and Welfare in Helsinki wanted to see which airport surfaces harboured the highest number of respiratory viruses. Dr Niina Ikonen, a virology expert, and her team collected surface and air samples from Helsinki-Vantaa airport during the peak of the 2015-2016 flu season.
Some 20 million passengers pass through Finland’s busiest airport every year, making contact with surfaces such as armrests, escalator handrails, toys in the children’s play area, trolley handles and luggage trays. Researchers swabbed these surfaces and tested them for viruses such as influenza, respiratory syncytial virus, adenovirus, rhinovirus, and coronavirus.
The results, published in the journal BMC Infectious Diseases, showed viruses were present on 10 per cent of the surfaces examined. Plastic security trays, which we all have to handle, were found to have the highest concentration of viruses. Perhaps the most unusual positive swab location was the buttons on the credit card payment pad at the airport pharmacy. Rhinoviruses – the culprit for the common cold – were the most widespread. But all of the viruses, including influenza A, were present to some degree.
Study co-author Jonathan Van Tam said: “People can help to minimise contagion by hygienic hand-washing and coughing into a handkerchief, tissue, or sleeve at all times, but especially in public places.
“These simple precautions can help prevent pandemics and are most important in crowded areas like airports that have a high volume of people travelling to and from many different parts of the world,” he added.
The continuous growth in air travel, especially ultra long-haul flights, increases the likelihood of rapid spread of infectious diseases between countries and continents. Air travel made possible the spread of severe acute respiratory syndrome (SARS) from Hong Kong in 2003 to several countries in a very short time. And SARS was the first disease to really highlight the risk of respiratory infection being spread between airplane passengers.
We breathe recycled air when travelling in aircraft. Older aeroplanes were designed to supply fresh air through the cabin. Newer aircraft, in an effort to cut airlines’ fuel bills, use a system of recirculating air.
Although rare, there have been reports of TB being transmitted to fellow passengers by an air traveller with an actively infectious form of the disease. Caused by the bacteria mycobacterium tuberculosis, TB is spread by droplets in the air. A person with infectious TB can expel TB germs when they cough or sneeze and people in the surrounding area can then inhale these. Each person with active infectious TB infects on average 10-15 people a year. Investigations of in-flight transmission of tuberculosis suggest the risk of disease transmission to other symptom-free passengers within the aircraft cabin is associated with sitting within two rows of a contagious passenger for a flight time of more than eight hours.
But back to the airport security trays, into which we are obliged to decant hand luggage and personal items. These plastic boxes typically cycle with high frequency to subsequent passengers, and are usually grabbed with a wide palm surface area and strong grip. Are security trays routinely disinfected? And should it be mandatory to sanitise our hands with alcohol hand rub before and after security screening?
Good hand hygiene has been proven to reduce the risk of disease transmission, and, as air travellers, we should make it part of our normal travel routine.
Here’s to a healthy new year.