Reaching for the sky with infection prevention and disease control strategies

With millions of aircraft passengers crossing the globe every year, and this number set to reach over 8 billion by 2037, communicable disease prevention and infection control strategies are needed to mitigate global outbreaks.

In the 1970s, Continental Airlines CEO Robert F Six said, “I’ve never known an industry that can get into people’s blood the way aviation does.”

Since then, air travel has become incredibly popular and accessible, with high volumes of passengers moving from one side of the world to the other in less than 24 hours.¹

Passenger volume and risk

According to the Australian Government Department of Infrastructure, Transport, Cities and Regional Development, passengers made 42.3 million journeys to/from Australia in the year leading up to September 2019.² The International Air Transport Association forecasts that the number of airline passengers worldwide will reach 8.2 billion in 2037, with the Asia–Pacific region driving the biggest growth — more than half the total number of new passengers over the next 20 years are estimated to come from these markets.³

With air travel comes the rapid spread of pathogens and dissemination of infectious diseases. Documented outbreaks of serious airborne infectious diseases associated with commercial air travel include influenza, MERS-CoV, SARS and measles, all of which are facilitated by high volumes of human intercontinental movement.^4-7

The ability to travel from one continent to another in less than 24 hours presents significant challenges to public health. Travellers incubating infectious diseases, but not showing signs of infection, pass rudimentary health screening checkpoints and reach their destination undetected, having exposed many travellers in confined spaces within aircraft and airports.⁸

Certain travel destinations are particularly challenging. People travelling to countries with poor sanitation and a high burden of antimicrobial resistance such as the Western Pacific, Southeast Asia and Eastern Mediterranean regions are at a high risk of exposure to antibiotic-resistant microorganisms. One recent study estimated that over 300 million travellers visit these high-risk areas each year and more than 20% return as new carriers of resistant organisms.⁹ These popular destinations, as well as the Middle East, have high rates of extended-spectrum beta-lactamase (ESBL) resistance, one of the most commonly acquired resistance mechanisms worldwide.¹⁰

The spread of resistance

Australia is not exempt from the problem. A case of de novo drug-resistant Candida auris in a patient at a Melbourne hospital — likely acquired during the patient’s stay in a UK hospital — is a reminder of the growing pace and ease with which resistance spreads globally.¹¹

In traditional healthcare settings, infection prevention and disease control practices are deployed to break the chain of infection.¹² This risk-management approach provides patients, healthcare workers and others with protection from infection (Figure 1). Standard and transmission-based precautions, such as effective hand hygiene, surface cleaning and cough etiquette, are also relevant in non-healthcare settings.

Figure 1. Breaking the chain of infection.

Airlines provide passengers with a range of preventive travel-related health advice, predominately focused on the risks associated with oedema, jet lag, dehydration and venous thromboembolism.¹³ However, there is a growing body of research demonstrating an ongoing lack of passenger information with respect to infection control and the prevention of infectious diseases associated with air travel.

Raising passenger awareness via in-flight channels

Containing and preventing the spread of infectious disease is critical to global health, yet opportunities to provide passengers with advice and guidance via official airline media are missed. For example, basic, effective measures such as hand hygiene can help passengers stay healthy and avoid illness, as well as reduce the risk of infectious disease outbreaks.

Research conducted in 1997 by Australian researcher Professor Peter A Leggat, published in the Journal of Travel Medicine, indicated that commercial airline in-flight magazines were an underutilised source of health advice.¹⁴ More than 20 years later, our research team examined the content of in-flight magazines for the two leading global airline conglomerates for passenger health and wellbeing information relating to infection control and prevention of infectious diseases: very little has changed.¹⁵

Another recent study published in the journal Travel Medicine and Infectious Diseases indicates that most official websites for global commercial passenger airlines contain little to no information about infection control and the prevention of infectious diseases.¹

In terms of passenger health education and communicable disease prevention, in-flight media channels are an underutilised resource with potential for future air travel infection control strategies. Investigating how best to use these channels will be vital as the global population increases and with it, the volume of aircraft passengers.

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Editor’s note

The recent 2019 n-CoV coronavirus outbreak originating in Wuhan is another example highlighting how quickly an infection can spread across the globe via air travel.

Amending or suspending air travel forms an important part of infection control in the case of a health emergency, as demonstrated with the recent coronavirus outbreak. China has imposed rigid travel restrictions in an attempt to contain the epidemic. Many airlines have offered ticket refunds or discontinued or cut services to and from mainland China. In Australia, Tigerair is contacting hundreds of passengers from 13 different flights after two people who travelled on the same plane tested positive to coronavirus. The airline pulled the plane from service on Thursday after Queensland Health alerted it to a positive case of coronavirus on board. Tigerair said the plane was taken out of service as a precautionary measure for extra cleaning.

Experts in population mapping at the University of Southampton have identified cities and provinces within mainland China, and cities and countries worldwide, which are at high risk from the spread of 2019-nCoV.

The university’s WorldPop team reported that Bangkok is currently the city most at risk from a global spread of the virus, based on the number of air travellers predicted to arrive there from the worst affected cities in mainland China. Hong Kong is second on the list, followed by Taipei. Sydney (12), New York (16) and London (19) are among 30 other major international cities ranked in the research.

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*Dr Cristina Sotomayor-Castillo is a Research Fellow at the Susan Wakil School of Nursing and Midwifery and Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney.
**Mr. Jeremy Malik is a Research Affiliate at the Susan Wakil School of Nursing and Midwifery and Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney.
***Professor Ramon Shaban is the Clinical Chair and Professor of Infection Prevention and Disease Control within the Marie Bashir Institute for Infectious Diseases and Biosecurity and Susan Wakil School of Nursing and Midwifery at the University of Sydney and the Division of Infectious Diseases and Sexual Health at Westmead Hospital and Western Sydney Local Health District.

References

1. Shaban RZ, Sotomayor-Castillo CF, Malik J, Li C. Global commercial passenger airlines and travel health information regarding infection control and the prevention of infectious disease: What's in a website? Travel Med Infect Dis. 2019:101528.
2. Australian Government. Department of Infrastructure Regional Development and Cities. International airline activity. Available from: https://bitre.gov.au/statistics/aviation/international.aspx [Accessed 30 November 2019]
3. International Air Transport Association. IATA Forecast Predicts 8.2 billion Air Travelers in 2037. Available from: https://www.iata.org/pressroom/pr/Pages/2018-10-24-02.aspx. [Accessed 5 December 2019]
4. Regan JJ, Jungerman MR, Lippold SA, Washburn F, Roland E, Objio T, et al. Tracing Airline Travelers for a Public Health Investigation: Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Infection in the United States, 201 Public Health Reports. 2016;131(4):552-9.
5. Brannen DE, Alhammad A, Branum M, Schmitt A. International Air Travel to Ohio, USA, and the Impact on Malaria, Influenza, and Hepatitis A. Scientifica. 2016;2016:8258946.
6. Edelson PJ. Patterns of measles transmission among airplane travelers. Travel Med Infect Dis. 2012;10(5-6):230-5.
7. Goubar A, Bitar D, Cao WC, Feng D, Fang LQ, Desenclos JC. An approach to estimate the number of SARS cases imported by international air travel. Epidemiol Infect. 2009;137(7):1019-31.
8. Mangili A, Gendreau MA. Transmission of infectious diseases during commercial air travel. Lancet. 2005;365(9463):989-96.
9. Kuenzli E. Antibiotic resistance and international travel: Causes and consequences. Travel Med Infect Dis. 2016;14(6):595-8.
10. Woerther PL, Andremont A, Kantele A. Travel-acquired ESBL-producing Enterobacteriaceae: impact of colonization at individual and community level. J Travel Med. 2017;24(suppl_1):S29-s34.
11. Victoria Health. Candida auris case detected in Victoria: Health Victoria. Available from: https://www2.health.vic.gov.au/about/news-and-events/healthalerts/candida-auris-case-detected-in-victoria. [Accessed 22 November 2019]
12. National Health and Medical Research Council. Australian Guidelines for the Prevention and Control of Infection in Healthcare. 2019. Available from: https://www.nhmrc.gov.au/sites/default/files/documents/attachments/19269%20NHMRC%20-%20Infection%20Control%20Guidelines-accessible.pdf [Accessed 4 November 2019]
13. Belcaro G, Cornelli U, Dugall M, Hosoi M, Cotellese R, Feragalli B. Long-haul flights, edema, and thrombotic events: prevention with stockings and Pycnogenol(R) supplementation (LONFLIT Registry Study). Minerva Cardioangiologica Europea. 2018;66(2):152-9.
14. Leggat PA. Travel Health Advice Provided by In-flight Magazines of International Airlines in Australia. J Travel Med. 1997;4(2):102-3.
15. Shaban RZ, Sotomayor-Castillo CF, Jakrot H, Jiang P. Passenger travel health advice regarding infection control and the prevention of infectious diseases: What’s in airline inflight magazines? Travel Med Infect Dis. 2019.

Image credit: ©stock.adobe.com/au/den-belitsky