Mr. Emil Pavlík MD
Future Forces Forum
Faculty of Biomedical Engineering
Czech Technical University in Prague
Does current maintenance of commertial aircraft cabin aircondition filters limit or support the risk of infectious agent transmission?
Daily, Tens of thousands local, regional, international, continental and intercontinental commertial flights are performed to carry passengers to desired destinations. Flying became an integral part of or traveling and, based on number of accident victims, it is concidered as most safety way of transportation. In recent years decreased also the number of terrorist attacs on aircraft due to significant improvement of safety control mechanisms impleemented by both the carriers and airport authorities. The chance to bring gun, explosive , toxic gas or liquid to the aircraft is close to zero.
But – can we say the same about microbes – bacteria, fungi and viruses? Is it easy or difficult to place a person with itransmittable infectious disease in the aircraft?
Contemporary Migration with 70 million refugees all over the world changes significantly global epidemiological situation. Emerging Infections of different origin present a great challenge for Health Care systems of different countries, including the most developed ones. Migrants suffer different diseases, which are uncommon in desired asyl countries. Therefor infectious diseases could be dangerous. Terrestral transit routes usualy filter sick people, air transport does not. For developed european countries presents the only way, how to bring in epidemiologically dangerous infections.
The most frequently used commertial aircrafts – Boeing B 737 series and Airbus A 319/320 – their producers equipe with cabin air-condition HEPA-filtres (0.03 micrometer micropores) Recommended life is 500 flight hours. This should decrease the number of microbes significantly – except viruses of less than 30 nanometer size. There is no official ICAO guideline determining interval for cabin air-condition filter change and the filter type to be used. It is completely on airline decission. So changing filters and cleaning the system as an integral part of regular aircraft control service is common practice.
We have analysed filter microbial content on both sides of the filter , taken out of the system after more than 4.500 flight hours. On the blow-out surface (after filtration) we detected 14 bacterial pathogens, out of which 5 with aerogenic transmission. Concerning the size of bacteria having passed through the micropore filter (several micrometers) it is evident that cabin-air filtration in this aircraft has been insufficient and – besides bacteria, filter has been penetrable for all viruses.
If such long period of filter usage is a common practice, antiepidemiological impediments in case of passenger with infectious disease abord – testing and observation of passengers seated two rows in front and two rows behind is insufficient. Complains of crew members on frequent respiratory infections are fully legitimate.
Assistant Professor Charles University, 1st Faculty of Medicine, Department of Immunology and Microbiology, Assistant Professor Czech Technical University in Prague, Faculty of Biomedical Engineering, 36 years experience on teaching microbiology in pregradual studies, examiner since 1998, 23 years in postgraduate studies
Head of the Diagnostic Laboratory on Serology and Molecular Biology Techniques and STDs, Department of Medical Biochemistry and Laboratory Diagnostics, General Faculty Hospital in Prague
Licence for Chief Physician – Head of the Diagnostic Laboratory (Czech Chambre of Physicians, 2000, exspires 2020)