Traveling by plane doesn’t necessarily increase the risk of contracting a communicable disease more than another kind of mass transit, according to the World Health Organization, as ventilation systems on aircraft use filters to trap bacteria and viruses before air is recirculated.
“Ventilation rates provide a total change of air 20 to 30 times per hour. Most modern aircraft have re-circulation systems, which recycle up to 50% of cabin air. The recirculated air is usually passed through HEPA (high-efficiency particulate air) filters, of the type used in hospital operating theaters and intensive care units, which trap dust particles, bacteria, fungi and viruses.”
Airplane air is usually recirculated through the kind of filters used in ICUs.
“Transmission of infection may occur between passengers who are seated in the same area of an aircraft, usually as a result of the infected individual coughing or sneezing or by touch,” WHO noted on its website. “This is no different from any other situation in which people are close to each other, such as on a train or bus or in a theatre.”
Others say such filters are imperfect. “HEPA filters are commonly thought to be impenetrable, but in fact they are only 99.97% efficient at collecting the most-penetrating particle,” one 2009 study concluded. “While this is an impressive collection efficiency, HEPA filters may not provide adequate protection for all threats: viruses are sub-micron in size and have small minimum infections doses.”
Travelers should still disinfect where they are seated, wash their hands often, avoid touching their face and try to stay away from people who are coughing or sneezing, regardless of where or how they travel. Travel experts recommend that travelers bring all necessary documentation including health-insurance cards, hand sanitizer and additional doses of medication.