Research on the Transmission of Disease in Airports and on Aircraft (2010)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

12 SESSIoN 2 Practical Case-Response Approaches to Investigating the Spread of Disease in Airports and on Aircraft Dan fishbein, Centers for Disease Control and Prevention (Presenter) Hannah L. Kirking, Centers for Disease Control and Prevention Jennifer Cortes, Centers for Disease Control and Prevention Sherry Burrer, Centers for Disease Control and Prevention and New Hampshire Department of Health and Human Services Aron Hall, Centers for Disease Control and Prevention Nicole J. Cohen, Centers for Disease Control and Prevention Harvey Lipman, Centers for Disease Control and Prevention Curi Kim, Centers for Disease Control and Prevention Elizabeth R. Daly, New Hampshire Department of Health and Human Services Itamar Grotto, Israel Ministry of Health (Presenter) Shepherd Roee Singer Emilia Anis norovirus TrAnsmission on AircrAfT Dan Fishbein (Presenter), Hannah L. Kirking, Jennifer Cortes, Sherry Burrer, Aron Hall, Nicole J. Cohen, Harvey Lipman, Curi Kim, and Elizabeth R. Daly An outbreak of gastroenteritis among members of a tour group on an airplane resulted in an emergency diversion. An investigation was conducted to determine the etiology of the outbreak, assess whether transmis- sion occurred onboard the airplane, and describe risk factors for transmission. Case patients, defined as pas- sengers or crew members with vomiting or diarrhea, were asked to submit stool samples for norovirus labo- ratory testing. Fifteen (41%) tour group members met the case definition, with most illnesses occurring before or during the flight. Seven (8%) passengers who were not tour group members met the case definition after the flight. Norovirus genogroup II was detected by reverse transcription–polymerase chain reaction (PCR) in stools from case patients in both groups. Multivari- ate logistic regression analysis showed that sitting in an aisle seat and sitting near any tour group member were associated with developing illness. Transmission of norovirus likely occurred during the flight, despite its short duration. swine flu A/h1n1 TrAnsmission viA The AviATion secTor Itamar Grotto (Presenter), Shepherd Roee Singer, and Emilia Anis Pandemic influenza A/H1N1 2009 is now well estab- lished in all countries. While the northern hemisphere prepares to mitigate the effects of an anticipated “second wave,” it is informative to look back at the early stages of the pandemic when containment was still a central strategy. This presentation describes the case of an Israeli traveler returning from Central America with influenza A/H1N1 2009 and considers the implications of in-flight transmission. The first case of influenza A/H1N1 2009 was diag- nosed in Israel on April 24, 2009, in a 26-year-old man who returned that day from Mexico. Israel was the sixth country in the world to confirm a case of the disease. The first steps taken by the Israeli Ministry of Health were defined as the “containment phase.” They included

13PRACTICAL CASE-RESPoNSE APPRoACHES mainly hospitalization and treating all patients with osel- tamivir, adding swine flu to the list of notifiable diseases in Israel, and epidemiologic investigation of each case. The objectives of the investigation were to identify the possible source of infection as well as contact tracing. As for travelers, a special clinic was opened at Israel’s only international airport, and travelers from Mexico were examined routinely and asked to stay in voluntary quar- antine for 7 days and to go to an emergency room if they developed fever. The Israeli Ministry of Health recom- mended that people postpone travels to Mexico. Case A This case involves a 22-year-old Israeli woman who returned from Mexico through Madrid (May 2, 2009). on a flight from Madrid to Tel Aviv, she had fever, shiv- ers, cough, sore throat, rhinorrhea, weakness, and head- ache. Upon landing, she did not report to the airport clinic but went directly to an emergency room, where she tested positive for influenza A/H1N1 2009 by using the PCR technique on her nasopharyngeal specimen. The Ministry of Health control measures included a recommendation to all travelers on Case A’s Madrid to Tel Aviv flight to stay at home for 7 days (voluntary quarantine) and to report to an emergency room imme- diately if they had influenza-like symptoms and fever. The recommendation was publicized in the Israeli media (television, radio, and Internet). Case B This case involves a 59-year-old Israeli woman who became ill in Israel on May 4, 2009. She had fever, cough, sneezing, and joint pain. She tested positive for influenza A/H1N1 2009 by PCR on May 5, 2009. The epidemiologic investigation disclosed that the woman had left Israel traveling to Guatemala via Madrid on April 10, 2009. After touring Guatemala, she flew to Havana, Cuba, on April 22. Her return flight to Israel left Cuba on April 30 and she made a brief stop- over in Madrid. After spending 9 h on May 1 in the city of Madrid and at various locations in the Madrid air- port, including 90 min in the preflight waiting area, she boarded a 23:30 flight to Israel that arrived in Tel Aviv on the morning of May 2. on the flight from Madrid to Tel Aviv, she sat one row in front of Case A. Outcome Both women were hospitalized for 7 days with mild ill- ness, were treated with oseltamivir, and fully recovered. No additional transmission from the two patients was identified (including Case A’s boyfriend, who sat next to her during the flight). Discussion Case A was symptomatic during the flight and was therefore certainly infectious at that time. Given her close proximity to Case B, and the lack of any other purported sources of contagion, in-flight transmission is viewed as the most likely cause of the infection spread- ing to Case B. Contagion in Havana or Madrid or in the waiting rooms of the respective airports cannot be ruled out; however, no sustained community transmission was recorded in Cuba or Madrid at the time, and the epidemiologic investigation did not uncover any known contact with potentially infectious individuals in those settings. Aircraft manufacturers have made great advances in cabin safety, and the risk of transmission of infectious disease aboard aircraft is very low. Cabin air systems in modern aircraft provide about 50% of the air from outside; the remainder is from recirculated air. Airflow is supplied at a rate of 20 to 30 air changes per hour. High-efficiency particulate air filters, similar to those used in hospital operating theatres and intensive care units, capture >99% of bacteria, fungi, and viruses (1, 2). However, no ventilation can completely prevent air- borne transmission of infectious particles, particularly from passengers sitting in close proximity. Thus, despite the effectiveness of modern filtration systems, airline passengers remain at some risk of direct infection in the cabin as well as in preflight waiting areas and on shuttle buses. Though rare, tuberculosis transmission has been documented (3, 4) and remains a long-standing con- cern among public health officials. More recently, five flights were associated with probable in-flight transmis- sion of severe acute respiratory syndrome, affecting 37 people (5, 6). In-flight transmission of measles has been reported (7), as has influenza (8–10). However, Han and colleagues demonstrated a lack of airborne transmission during an outbreak of influenza A/H1N1 2009 among tour group members in China (11). Conclusion Airlines have undertaken a variety of measures over the years to minimize the risk of in-flight transmission of infectious agents. These measures cannot eliminate that risk entirely. Passengers should consult travel experts, ensure that they have completed recommended pre- travel immunizations, and inquire about current health

14 RESEARCH oN THE TRANSMISSIoN of DISEASE IN AIRPoRTS AND oN AIRCRAfT guidelines for travelers. People who are unwell should always consult a doctor before traveling. There is a need for international guidelines to deal with medical and ethical issues related to pretravel screening and restrictions. References Cabin Air Quality—Risk of Contagious Viruses1. . Inter- national Air Transport Association, Montreal, Quebec, Canada. www.iata.org/NR/rdonlyres/E81DEB5C-f3C5- 4Cf7-8208-9E96123D4781/0/cabin_air_quality.pdf. International Travel and Health2. . World Health organiza- tion, Geneva, Switzerland, 2009. www.who.int/ith/chap ters/en/index.html. Kenyon, t. A., S. E. Valway, w. w. ihle, i. m. onorato, 3. and K. G. Castro. Transmission of Multidrug Resistant Mycobacterium tuberculosis During a Long Airplane flight. New England Journal of Medicine, Vol. 334, 1996, pp. 933–938. Exposure of Passengers and flight Crew to 4. Mycobacte- rium tuberculosis on Commercial Aircraft, 1992–1995. Morbidity and Mortality Weekly Report, Vol. 44, 1995, pp. 137–40. olsen, J. A., H.-L. Chang, T. Y.-Y. Cheung, A. f.-U. Tang, 5. T. L. fisk, S. P.-L. ooi, H.-W. Kuo, D. D.-S. Jiang, K.-T. Chen, J. Lando, K.-H. Hsu, T.-J. Chen, and S. f. Dowell. Transmission of the Severe Acute Respiratory Syndrome on Aircraft. New England Journal of Medicine, Vol. 349, 2003, pp. 2416–2422. Vogt, t. m., m. A. guerra, E. w. Flagg, t. g. Ksiazek, S. 6. A. Lowther, and P. M. Arguin. Risk of Severe Acute Respi- ratory Syndrome–Associated Coronavirus Transmission Aboard Commercial Aircraft. Journal of Travel Medicine, Vol. 13, 2006, pp. 268–272. Slater, P. E., E. Anis, and A. Bashary. An outbreak of 7. Measles Associated with a New York–Tel Aviv flight. Travel Medicine International, Vol. 13, 1995, pp. 92–95. Marsden, A. G. Influenza outbreak Related to Air Travel. 8. Medical Journal of Australia, Vol. 179, 2003, pp. 172– 173. Moser, M. R., T. R. Bender, H. S. Margolis, G. R. Noble, 9. A. P. Kendal, and D. G. Ritter. An outbreak of Influenza Aboard a Commercial Airline. American Journal of Epi- demiology, Vol. 110, 1979, pp. 1–6. Klontz, K. C., N. A. Hynes, R. A. Gunn, M. H. Wilder, M. 10. W. Harmon, and A. P. Kendal. An outbreak of Influenza A/Taiwan/1/86 Infections at a Naval Base and Its Associa- tion with Airplane Travel. American Journal of Epidemi- ology, Vol. 129, 1989, pp. 341–348. Han, K., X. Zhu, f. He, L. Liu, L. Zhang, H. Ma, X. Tang, 11. T. Huang, G. Zeng, and B.-P. Zhu. Lack of Airborne Transmission During outbreak of Pandemic (H1N1) 2009 Among Tour Group Members, China, June 2009. Emerging Infectious Diseases, Vol. 15, No. 10, 2009.