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. 2010 May 21:340:c2424.
doi: 10.1136/bmj.c2424.

Transmission of pandemic A/H1N1 2009 influenza on passenger aircraft: retrospective cohort study

Michael G Baker  1 , Craig N Thornley, Clair Mills, Sally Roberts, Shanika Perera, Julia Peters, Anne Kelso, Ian Barr, Nick Wilson
Affiliations

Transmission of pandemic A/H1N1 2009 influenza on passenger aircraft: retrospective cohort study

Michael G Baker et al. BMJ. .

Abstract

Objectives: To assess the risk of transmission of pandemic A/H1N1 2009 influenza (pandemic A/H1N1) from an infected high school group to other passengers on an airline flight and the effectiveness of screening and follow-up of exposed passengers.

Design: Retrospective cohort investigation using a questionnaire administered to passengers and laboratory investigation of those with symptoms.

Setting: Auckland, New Zealand, with national and international follow-up of passengers.

Participants: Passengers seated in the rear section of a Boeing 747-400 long haul flight that arrived on 25 April 2009, including a group of 24 students and teachers and 97 (out of 102) other passengers in the same section of the plane who agreed to be interviewed.

Main outcome measures: Laboratory confirmed pandemic A/H1N1 infection in susceptible passengers within 3.2 days of arrival; sensitivity and specificity of influenza symptoms for confirmed infection; and completeness and timeliness of contact tracing.

Results: Nine members of the school group were laboratory confirmed cases of pandemic A/H1N1 infection and had symptoms during the flight. Two other passengers developed confirmed pandemic A/H1N1 infection, 12 and 48 hours after the flight. They reported no other potential sources of infection. Their seating was within two rows of infected passengers, implying a risk of infection of about 3.5% for the 57 passengers in those rows. All but one of the confirmed pandemic A/H1N1 infected travellers reported cough, but more complex definitions of influenza cases had relatively low sensitivity. Rigorous follow-up by public health workers located 93% of passengers, but only 52% were contacted within 72 hours of arrival.

Conclusions: A low but measurable risk of transmission of pandemic A/H1N1 exists during modern commercial air travel. This risk is concentrated close to infected passengers with symptoms. Follow-up and screening of exposed passengers is slow and difficult once they have left the airport.

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Conflict of interest statement

Competing interests: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: (1) MGB was partly supported by a grant from the Centers for Disease Control and Prevention (USA) for research on pandemic influenza (1 U01 CI000445-01); all other authors declare no financial support for the submitted work from anyone other than their employer; (2) No financial relationships with commercial entities that might have an interest in the submitted work; (3) No spouses, partners, or children with relationships with commercial entities that might have an interest in the submitted work; (4) No non-financial interests that may be relevant to the submitted work.

Figures

None
Seating plan of rear section of aircraft showing passengers according to their infection category and seating position
See this image and copyright information in PMC

References

    1. Ministry of Health. New Zealand influenza pandemic action plan. Ministry of Health, 2006.
    1. McLeod M, Kelly H, Wilson N, Baker MG. Border control measures in the influenza pandemic plans of six South Pacific nations: a critical review. N Z Med J 2008;121:62-72. - PubMed
    1. Mangili A, Gendreau MA. Transmission of infectious diseases during commercial air travel. Lancet 2005;365:989-96. - PMC - PubMed
    1. Marsden AG. Outbreak of influenza-like illness related to air travel. Med J Aust 2003;179:172-3. - PubMed
    1. Moser MR, Bender TR, Margolis HS, Noble GR, Kendal AP, Ritter DG. An outbreak of influenza aboard a commercial airliner. Am J Epidemiol 1979;110:1-6. - PubMed

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