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Mahmoud S, Bennett J, Jones B, Hosni M. A comparative analysis of potential aerosol exposure in a wide-body aircraft cabin using tracer gas and fluorescent particles. THE INTERNATIONAL JOURNAL OF VENTILATION 2024; 23:104-124. [PMID: 38799196 PMCID: PMC11120351 DOI: 10.1080/14733315.2023.2290920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 11/28/2023] [Indexed: 05/29/2024]
Abstract
We compare two aerosol surrogate tracers in aircraft cabins for breathing and coughing sources: tracer gas collected in the ACER Boeing 767 mock-up and fluorescent particles collected in an actual Boeing 767 aircraft by the US Transportation Command (TRANSCOM). Each source was located individually in window and middle seats. Exposure generally decreased with source distance. A window seat breathing source resulted in good agreement between datasets for exposure (as percent of release) for the TRANSCOM hangar-AFT testing mode, which corresponds to the 11-row cabin ACER laboratory space. Average tracer gas exposure for a middle seat breathing source was higher in the ACER study than the fluorescent particle tracer exposure in the TRANSCOM study. Using a coughing source in a window seat, the exposure for the TRANSCOM data was higher within the first two rows from the source before decreasing to and tracking with the ACER levels, until increasing after about 5 m away. A similar trend was recorded for a middle seat coughing source with higher overall exposure for the TRANSCOM data. Sources of exposure variation between the studies include particle deposition. This work helps optimize aerosol dispersion research in aircraft cabins and provides some validation to the existing studies.
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Affiliation(s)
- Seif Mahmoud
- National Institute for Occupational Safety and Health, Centres for Disease Control and Prevention, U.S. Department of Health and Human Services, Division of Field Studies and Engineering, Cincinnati, OH, USA
| | - James Bennett
- National Institute for Occupational Safety and Health, Centres for Disease Control and Prevention, U.S. Department of Health and Human Services, Division of Field Studies and Engineering, Cincinnati, OH, USA
| | - Byron Jones
- Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS, USA
| | - Mohammad Hosni
- Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS, USA
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Lovey T, Hasler R, Gautret P, Schlagenhauf P. Travel-related respiratory symptoms and infections in travellers (2000-22): a systematic review and meta-analysis. J Travel Med 2023; 30:taad081. [PMID: 37310895 PMCID: PMC10481419 DOI: 10.1093/jtm/taad081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/15/2023]
Abstract
BACKGROUND Respiratory tract infections (RTIs) are common in travellers due to the year-round or seasonal presence of respiratory pathogen and exposure to crowded environments during the itinerary. No study has systematically examined the burden of RTI infections among travellers. The aim of this systematic review and meta-analysis is to evaluate the prevalence of RTIs and symptoms suggestive of RTIs among travellers according to risk groups and/or geographic region, and to describe the spectrum of RTIs. METHODS The systematic review and meta-analysis was registered in PROSPERO (CRD42022311261). We searched Medline, Embase, Scopus, Cochrane Central, Web of Science, Science Direct and preprint servers MedRxiv, BioRxiv, SSRN and IEEE Xplore on 1 February 2022. Studies reporting RTIs or symptoms suggestive of RTIs in international travellers after 1 January 2000 were eligible. Data appraisal and extraction were performed by two authors, and proportional meta-analyses were used to obtain estimates of the prevalence of respiratory symptoms and RTIs in travellers and predefined risk groups. FINDINGS A total of 429 articles on travellers' illness were included. Included studies reported 86 841 symptoms suggestive of RTIs and 807 632 confirmed RTIs. Seventy-eight percent of reported respiratory symptoms and 60% of RTIs with available location data were acquired at mass gatherings events. Cough was the most common symptom suggestive of respiratory infections, and the upper respiratory tract was the most common site for RTIs in travellers. The prevalence of RTIs and respiratory symptoms suggestive of RTIs were 10% [8%; 14%] and 37% [27%; 48%], respectively, among travellers. Reporting of RTIs in travellers denoted by publication output was found to correlate with global waves of new respiratory infections. INTERPRETATION This study demonstrates a high burden of RTIs among travellers and indicates that travellers' RTIs reflect respiratory infection outbreaks. These findings have important implications for understanding and managing RTIs among travellers.
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Affiliation(s)
- Thibault Lovey
- Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Hirschengraben 84, 8001 Zürich Switzerland
| | - Robin Hasler
- HFR Fribourg – Cantonal Hospital, 1708 Fribourg, Switzerland
| | | | - Patricia Schlagenhauf
- Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Hirschengraben 84, 8001 Zürich Switzerland
- Department of Global and Public Health, MilMedBiol Competence Centre, Epidemiology Biostatistics and Prevention Institute, WHO Collaborating Centre for Travellers’ Health, Hirschengraben 84, 8001 Zürich, Switzerland
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Rafferty AC, Bofkin K, Hughes W, Souter S, Hosegood I, Hall RN, Furuya-Kanamori L, Liu B, Drane M, Regan T, Halder M, Kelaher C, Kirk MD. Does 2x2 airplane passenger contact tracing for infectious respiratory pathogens work? A systematic review of the evidence. PLoS One 2023; 18:e0264294. [PMID: 36730309 PMCID: PMC9894495 DOI: 10.1371/journal.pone.0264294] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 01/18/2023] [Indexed: 02/03/2023] Open
Abstract
We critically appraised the literature regarding in-flight transmission of a range of respiratory infections to provide an evidence base for public health policies for contact tracing passengers, given the limited pathogen-specific data for SARS-CoV-2 currently available. Using PubMed, Web of Science, and other databases including preprints, we systematically reviewed evidence of in-flight transmission of infectious respiratory illnesses. A meta-analysis was conducted where total numbers of persons on board a specific flight was known, to calculate a pooled Attack Rate (AR) for a range of pathogens. The quality of the evidence provided was assessed using a bias assessment tool developed for in-flight transmission investigations of influenza which was modelled on the PRISMA statement and the Newcastle-Ottawa scale. We identified 103 publications detailing 165 flight investigations. Overall, 43.7% (72/165) of investigations provided evidence for in-flight transmission. H1N1 influenza A virus had the highest reported pooled attack rate per 100 persons (AR = 1.17), followed by SARS-CoV-2 (AR = 0.54) and SARS-CoV (AR = 0.32), Mycobacterium tuberculosis (TB, AR = 0.25), and measles virus (AR = 0.09). There was high heterogeneity in estimates between studies, except for TB. Of the 72 investigations that provided evidence for in-flight transmission, 27 investigations were assessed as having a high level of evidence, 23 as medium, and 22 as low. One third of the investigations that reported on proximity of cases showed transmission occurring beyond the 2x2 seating area. We suggest that for emerging pathogens, in the absence of pathogen-specific evidence, the 2x2 system should not be used for contact tracing. Instead, alternate contact tracing protocols and close contact definitions for enclosed areas, such as the same cabin on an aircraft or other forms of transport, should be considered as part of a whole of journey approach.
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Affiliation(s)
- Anna C. Rafferty
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australian Capital Territory, Australia
- National Incident Centre, The Australian Government Department of Health, Canberra, Australian Capital Territory, Australia
| | - Kelly Bofkin
- Qantas Airways Limited, Mascot, New South Wales, Australia
- Virgin Australia Airlines, South Brisbane, Queensland, Australia
| | - Whitney Hughes
- Qantas Airways Limited, Mascot, New South Wales, Australia
| | - Sara Souter
- Qantas Airways Limited, Mascot, New South Wales, Australia
- Virgin Australia Airlines, South Brisbane, Queensland, Australia
| | - Ian Hosegood
- Qantas Airways Limited, Mascot, New South Wales, Australia
| | - Robyn N. Hall
- National Incident Centre, The Australian Government Department of Health, Canberra, Australian Capital Territory, Australia
| | - Luis Furuya-Kanamori
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Bette Liu
- School of Population Health, University of New South Wales, Kensington, New South Wales, Australia
| | | | - Toby Regan
- New Zealand Ministry of Health, Wellington, New Zealand
| | - Molly Halder
- New Zealand Ministry of Health, Wellington, New Zealand
| | - Catherine Kelaher
- National Incident Centre, The Australian Government Department of Health, Canberra, Australian Capital Territory, Australia
| | - Martyn D. Kirk
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australian Capital Territory, Australia
- National Incident Centre, The Australian Government Department of Health, Canberra, Australian Capital Territory, Australia
- * E-mail:
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4
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Guo Q, Wang J, Estill J, Lan H, Zhang J, Wu S, Yao J, Yan X, Chen Y. Risk of COVID-19 Transmission Aboard Aircraft: An Epidemiological Analysis Based on the National Health Information Platform. Int J Infect Dis 2022; 118:270-276. [PMID: 35331931 PMCID: PMC8935959 DOI: 10.1016/j.ijid.2022.03.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 02/23/2022] [Accepted: 03/15/2022] [Indexed: 12/26/2022] Open
Abstract
Objectives This study aims to investigate the risk of COVID-19 transmission on aircraft. Methods We obtained data on all international flights to Lanzhou, China, from June 1, 2020, to August 1, 2020, through the Gansu Province National Health Information Platform and the official website of the Gansu Provincial Center for Disease Control and Prevention. We then performed the statistical analysis. Results Three international flights arrived in Lanzhou. The flights had a total of 700 passengers, of whom 405 (57.9%) were male, and 80 (11.4%) were children under the age of 14 years. Twenty-seven (3.9%) passengers were confirmed to have COVID-19. Confirmed patients were primarily male (17, 65.4%) with a median age of 27.0 years. Most confirmed cases were seated in the middle rows of economy class or near public facility areas such as restrooms and galleys. The prevalence of COVID-19 did not differ between passengers sitting in the window, aisle, or middle seats. However, compared with passengers sitting in the same row up to 2 rows behind a confirmed case, passengers seated in the 2 rows in front of a confirmed case were at a slightly higher risk of being infected. Conclusions COVID-19 may be transmitted during a passenger flight, although there is still no direct evidence.
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Affiliation(s)
- Qiangqiang Guo
- School of Public Health, Lanzhou University, Lanzhou, China; Lanzhou University Institute of Health Data Science, Lanzhou, China; Lanzhou University, an Affiliate of the Cochrane China Network, Lanzhou, China; WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou, China
| | - Jianjian Wang
- School of Public Health, Lanzhou University, Lanzhou, China; Lanzhou University Institute of Health Data Science, Lanzhou, China; Lanzhou University, an Affiliate of the Cochrane China Network, Lanzhou, China; WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou, China
| | - Janne Estill
- Institute of Global Health, University of Geneva, Geneva, Switzerland; Institute of Mathematical Statistics and Actuarial Science, University of Bern, Bern, Switzerland
| | - Hui Lan
- School of Public Health, Lanzhou University, Lanzhou, China; Lanzhou University Institute of Health Data Science, Lanzhou, China; Lanzhou University, an Affiliate of the Cochrane China Network, Lanzhou, China; WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou, China
| | - Juanjuan Zhang
- School of Public Health, Lanzhou University, Lanzhou, China; Lanzhou University Institute of Health Data Science, Lanzhou, China; Lanzhou University, an Affiliate of the Cochrane China Network, Lanzhou, China; WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou, China
| | - Shouyuan Wu
- School of Public Health, Lanzhou University, Lanzhou, China; Lanzhou University Institute of Health Data Science, Lanzhou, China; Lanzhou University, an Affiliate of the Cochrane China Network, Lanzhou, China; WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou, China
| | - Jingwen Yao
- Health Statistics Information Center of Health Commission of Gansu Province, Lanzhou, China
| | - Xuanchen Yan
- Health Statistics Information Center of Health Commission of Gansu Province, Lanzhou, China.
| | - Yaolong Chen
- School of Public Health, Lanzhou University, Lanzhou, China; Lanzhou University Institute of Health Data Science, Lanzhou, China; Lanzhou University, an Affiliate of the Cochrane China Network, Lanzhou, China; WHO Collaborating Centre for Guideline Implementation and Knowledge Translation, Lanzhou, China.
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5
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Zhuang Z, Cao P, Zhao S, Han L, He D, Yang L. The shortage of hospital beds for COVID-19 and non-COVID-19 patients during the lockdown of Wuhan, China. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:200. [PMID: 33708827 PMCID: PMC7940947 DOI: 10.21037/atm-20-5248] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Background The 76-day lockdown of Wuhan city has successfully contained the first wave of the coronavirus disease 2019 (COVID-19) outbreak. However, to date few studies have evaluated the hospital bed shortage for COVID-19 during the lockdown and none for non-COVID-19 patients, although such data are important for better preparedness of the future outbreak. Methods We built a compartmental model to estimate the daily numbers of hospital bed shortage for patients with mild, severe and critical COVID-19, taking account of underreport and diagnosis delay. Results The maximal daily shortage of inpatient beds for mild, severe and critical COVID-19 patients was 43,960 (95% confidence interval: 35,246, 52,929), 2,779 (1,395, 4,163) and 196 (143, 250) beds in early February 2020. An earlier or later lockdown would have greatly increased the shortage of hospital beds in Wuhan. The overwhelmed healthcare system might have delayed the provision of health care to both COVID-19 and non-COVID-19 patients during the lockdown. The second wave in Wuhan could have occurred in June 2020 if social distancing measures had waned in early March 2020. The hospital bed shortage was estimated much smaller in the potential second wave than in the first one. Conclusions Our findings suggest that the timing and strength of lockdown is important for the containment of the COVID-19 outbreaks. The healthcare needs of non-COVID-19 patients in the pandemic warrant more investigations.
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Affiliation(s)
- Zian Zhuang
- Department of Applied Mathematics, Hong Kong Polytechnic University, Hong Kong, China
| | - Peihua Cao
- Clinical Research Center, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Shi Zhao
- JC School of Public Health and Primary Care, Chinese University of Hong Kong, Hong Kong, China.,Shenzhen Research Institute of Chinese University of Hong Kong, Shenzhen, China
| | - Lefei Han
- School of Nursing, Hong Kong Polytechnic University, Hong Kong, China
| | - Daihai He
- Department of Applied Mathematics, Hong Kong Polytechnic University, Hong Kong, China
| | - Lin Yang
- School of Nursing, Hong Kong Polytechnic University, Hong Kong, China
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Li J, Huang C, Wang Z, Yuan B, Peng F. The airline transport regulation and development of public health crisis in megacities of China. JOURNAL OF TRANSPORT & HEALTH 2020; 19:100959. [PMID: 33020730 PMCID: PMC7527282 DOI: 10.1016/j.jth.2020.100959] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 05/10/2023]
Abstract
BACKGROUND The Civil Aviation Administration of China (CAAC) declares the airline transport regulation in January 2020 to help retard the spread of the novel coronavirus disease in China. This study is to examine the effect of airline transport regulation on confirmed cases of the novel coronavirus disease in megacities in China. METHODS This study combines the multi-source data from the health data platform DXY, the airline data platform Airsavvi, the China Economic Internet Statistical Database and the China Railway website. The megacities whose airports have a passenger throughput of over 30 million per year (11 megacities: Wuhan, Beijing, Shanghai, Guangzhou, Chengdu, Shenzhen, Kunming, Xi'an, Chongqing, Hangzhou, Nanjing) are included in the analysis. The regression analysis is conducted in this study. RESULTS The curvilinear relationship between the limitation on air traffic and confirmed cases of the novel coronavirus disease is identified (coefficient of the linear term = -4.650, p-value < 0.01; coefficient of the quadratic term = 4.089, p-value < 0.01). CONCLUSIONS This study confirms the effectiveness of airline transport regulation in suppressing the development of this pandemic. The limitation on air traffic is found to negatively affect the confirmed cases in China's megacities. However, such effect marginally recedes as the strength of limitation intensifies. It suggests that comprehensive policy intervention is in need and air traffic can be one of important determinants that affect the epidemic development.
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Affiliation(s)
- Jiannan Li
- International School of Business & Finance, Sun Yat-sen University, Guangzhou, China
| | - Chulan Huang
- School of Tourism Management, Sun Yat-sen University, Guangzhou, China
| | - Zhaoguo Wang
- School of Economics and Management, Shenyang Agricultural University, Shenyang, China
| | - Bocong Yuan
- School of Tourism Management, Sun Yat-sen University, Guangzhou, China
| | - Fei Peng
- School of Tourism Management, Sun Yat-sen University, Guangzhou, China
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Ho HJ, Zhang ZX, Huang Z, Aung AH, Lim WY, Chow A. Use of a Real-Time Locating System for Contact Tracing of Health Care Workers During the COVID-19 Pandemic at an Infectious Disease Center in Singapore: Validation Study. J Med Internet Res 2020; 22:e19437. [PMID: 32412416 PMCID: PMC7252199 DOI: 10.2196/19437] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/14/2020] [Accepted: 05/14/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND In early 2020, coronavirus disease (COVID-19) emerged and spread by community and nosocomial transmission. Effective contact tracing of potentially exposed health care workers is crucial for the prevention and control of infectious disease outbreaks in the health care setting. OBJECTIVE This study aimed to evaluate the comparative effectiveness of contact tracing during the COVID-19 pandemic through the real-time locating system (RTLS) and review of the electronic medical record (EMR) at the designated hospital for COVID-19 response in Singapore. METHODS Over a 2-day study period, all admitted patients with COVID-19, their ward locations, and the health care workers rostered to each ward were identified to determine the total number of potential contacts between patients with COVID-19 and health care workers. The numbers of staff-patient contacts determined by EMR reviews, RTLS-based contact tracing, and a combination of both methods were evaluated. The use of EMR-based and RTLS-based contact tracing methods was further validated by comparing their sensitivity and specificity against self-reported staff-patient contacts by health care workers. RESULTS Of 796 potential staff-patient contacts (between 17 patients and 162 staff members), 104 (13.1%) were identified by both the RTLS and EMR, 54 (6.8%) by the RTLS alone, and 99 (12.4%) by the EMR alone; 539 (67.7%) were not identified through either method. Compared to self-reported contacts, EMR reviews had a sensitivity of 47.2% and a specificity of 77.9%, while the RTLS had a sensitivity of 72.2% and a specificity of 87.7%. The highest sensitivity was obtained by including all contacts identified by either the RTLS or the EMR (sensitivity 77.8%, specificity 73.4%). CONCLUSIONS RTLS-based contact tracing showed higher sensitivity and specificity than EMR review. Integration of both methods provided the best performance for rapid contact tracing, although technical adjustments to the RTLS and increasing user compliance with wearing of RTLS tags remain necessary.
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Affiliation(s)
- Hanley J Ho
- Department of Clinical Epidemiology, Office of Clinical Epidemiology, Analytics, and Knowledge (OCEAN), Tan Tock Seng Hospital, Singapore
| | - Zoe Xiaozhu Zhang
- Department of Clinical Epidemiology, Office of Clinical Epidemiology, Analytics, and Knowledge (OCEAN), Tan Tock Seng Hospital, Singapore
| | - Zhilian Huang
- Department of Clinical Epidemiology, Office of Clinical Epidemiology, Analytics, and Knowledge (OCEAN), Tan Tock Seng Hospital, Singapore
| | - Aung Hein Aung
- Department of Clinical Epidemiology, Office of Clinical Epidemiology, Analytics, and Knowledge (OCEAN), Tan Tock Seng Hospital, Singapore
| | - Wei-Yen Lim
- Department of Clinical Epidemiology, Office of Clinical Epidemiology, Analytics, and Knowledge (OCEAN), Tan Tock Seng Hospital, Singapore
| | - Angela Chow
- Department of Clinical Epidemiology, Office of Clinical Epidemiology, Analytics, and Knowledge (OCEAN), Tan Tock Seng Hospital, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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Houghton F. Geography, global pandemics & air travel: Faster, fuller, further & more frequent. J Infect Public Health 2019; 12:448-449. [PMID: 30878442 PMCID: PMC7129534 DOI: 10.1016/j.jiph.2019.02.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 02/26/2019] [Indexed: 11/30/2022] Open
Affiliation(s)
- Frank Houghton
- HEALR Research Group, Limerick Institute of Technology, Limerick, Ireland.
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9
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Weiss H, Hertzberg VS, Dupont C, Espinoza JL, Levy S, Nelson K, Norris S. The Airplane Cabin Microbiome. MICROBIAL ECOLOGY 2019; 77:87-95. [PMID: 29876609 PMCID: PMC6318343 DOI: 10.1007/s00248-018-1191-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/11/2018] [Indexed: 05/07/2023]
Abstract
Serving over three billion passengers annually, air travel serves as a conduit for infectious disease spread, including emerging infections and pandemics. Over two dozen cases of in-flight transmissions have been documented. To understand these risks, a characterization of the airplane cabin microbiome is necessary. Our study team collected 229 environmental samples on ten transcontinental US flights with subsequent 16S rRNA sequencing. We found that bacterial communities were largely derived from human skin and oral commensals, as well as environmental generalist bacteria. We identified clear signatures for air versus touch surface microbiome, but not for individual types of touch surfaces. We also found large flight-to-flight beta diversity variations with no distinguishing signatures of individual flights, rather a high between-flight diversity for all touch surfaces and particularly for air samples. There was no systematic pattern of microbial community change from pre- to post-flight. Our findings are similar to those of other recent studies of the microbiome of built environments. In summary, the airplane cabin microbiome has immense airplane to airplane variability. The vast majority of airplane-associated microbes are human commensals or non-pathogenic, and the results provide a baseline for non-crisis-level airplane microbiome conditions.
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Affiliation(s)
- Howard Weiss
- School of Mathematics, The Georgia Institute of Technology, 686 Cherry St. NW, Atlanta, GA 30313 USA
| | - Vicki Stover Hertzberg
- Nell Hodgson Woodruff School of Nursing, Emory University, 1520 Clifton Rd. NE, Atlanta, GA 30322 USA
| | - Chris Dupont
- J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA 92037 USA
| | - Josh L. Espinoza
- J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA 92037 USA
| | - Shawn Levy
- HudsonAlpha Institute for Biotechnology, 601 Genome Way, Huntsville, AL 35806 USA
| | - Karen Nelson
- J. Craig Venter Institute, 9714 Medical Center Drive, Rockville, MD 20850 USA
| | - Sharon Norris
- Boeing Health Services, The Boeing Company, 3156 160th Ave. NE, Bellevue, WA 98008-2245 USA
| | - The FlyHealthy Research Team
- School of Mathematics, The Georgia Institute of Technology, 686 Cherry St. NW, Atlanta, GA 30313 USA
- Nell Hodgson Woodruff School of Nursing, Emory University, 1520 Clifton Rd. NE, Atlanta, GA 30322 USA
- J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA 92037 USA
- HudsonAlpha Institute for Biotechnology, 601 Genome Way, Huntsville, AL 35806 USA
- J. Craig Venter Institute, 9714 Medical Center Drive, Rockville, MD 20850 USA
- Boeing Health Services, The Boeing Company, 3156 160th Ave. NE, Bellevue, WA 98008-2245 USA
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Abstract
Knowledge about the infection transmission routes is significant for developing effective intervention strategies. We searched the PubMed databases and identified 10 studies with 14 possible inflight influenza A(H1N1)pdm09 outbreaks. Considering the different mechanisms of the large-droplet and airborne routes, a meta-analysis of the outbreak data was carried out to study the difference in attack rates for passengers within and beyond two rows of the index case(s). We also explored the relationship between the attack rates and the flight duration and/or total infectivity of the index case(s). The risk ratios for passengers seated within and beyond the two rows of the index cases were 1.7 (95% confidence interval (CI) 0.98-2.84) for syndromic secondary cases and 4.3 (95% CI 1.25-14.54) for laboratory-confirmed secondary cases. Furthermore, with an increase of the product of the flight duration and the total infectivity of the index cases, the overall attack rate increased linearly. The study indicates that influenza A(H1N1)pdm09 may mainly be transmitted via the airborne route during air travel. A standardised approach for the reporting of such inflight outbreak investigations would help to provide more convincing evidence for such inflight transmission events.
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Abstract
Background With over two billion airline passengers annually, in-flight transmission of infectious diseases is an important global health concern. Many instances of in-flight transmission have been documented, but the relative influence of the many factors (see below) affecting in-flight transmission has not been quantified. Long-standing guidance by public health agencies is that the primary transmission risk associated with air travel for most respiratory infectious diseases is associated with sitting within two rows of an infectious passenger. The effect of proximity may be one of these factors. Objective The aim of this study was to determine the risk of infection within and beyond the 2-row rule given by public health guidance. Methods We searched the literature for reports of in-flight transmission of infection which included seat maps indicating where the infectious and infected passengers were seated. Findings There is a ∼ 6% risk to passengers seated within the 2-rows of infected individual(s) and there is ∼ 2% risk to passengers seated beyond 2-rows from the infectious individual. Discussion Contact tracing limited to passengers within 2-rows of the infectious individual(s) could fail to detect other cases of infections. This has important consequences for assessing the spread of infectious diseases. Conclusions Infection at a distance from the index case indicates other factors, such as airflow, movement of passenger/crew members, fomites and contacts between passengers in the departure gate before boarding, or after deplaning, are involved.
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Affiliation(s)
| | - Howard Weiss
- School of Mathematics, Georgia Institute of Technology, Atlanta, GA
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12
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Abstract
BACKGROUND Air travel is associated with the spread of influenza through infected passengers and potentially through in-flight transmission. Contact tracing after exposure to influenza is not performed systematically. We performed a systematic literature review to evaluate the evidence for influenza transmission aboard aircraft. METHODS Using PubMed and EMBASE databases, we identified and critically appraised identified records to assess the evidence of such transmission to passengers seated in close proximity to the index cases. We also developed a bias assessment tool to evaluate the quality of evidence provided in the retrieved studies. RESULTS We identified 14 peer-reviewed publications describing contact tracing of passengers after possible exposure to influenza virus aboard an aircraft. Contact tracing during the initial phase of the influenza A(H1N1)pdm09 pandemic was described in 11 publications. The studies describe the follow-up of 2,165 (51%) of 4,252 traceable passengers. Altogether, 163 secondary cases were identified resulting in an overall secondary attack rate among traced passengers of 7.5%. Of these secondary cases, 68 (42%) were seated within two rows of the index case. CONCLUSION We found an overall moderate quality of evidence for transmission of influenza virus aboard an aircraft. The major limiting factor was the comparability of the studies. A majority of secondary cases was identified at a greater distance than two rows from the index case. A standardized approach for initiating, conducting, and reporting contact tracing could help to increase the evidence base for better assessing influenza transmission aboard aircraft.
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Klaus J, Gnirs P, Hölterhoff S, Wirtz A, Jeglitza M, Gaber W, Gottschalk R. Disinfection of aircraft : Appropriate disinfectants and standard operating procedures for highly infectious diseases. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2017; 59:1544-1548. [PMID: 27785522 PMCID: PMC5122611 DOI: 10.1007/s00103-016-2460-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
For infectious diseases caused by highly pathogenic agents (e. g., Ebola/Lassa fever virus, SARS-/MERS-CoV, pandemic influenza virus) which have the potential to spread over several continents within only a few days, international Health Protection Authorities have taken appropriate measures to limit the consequences of a possible spread. A crucial point in this context is the disinfection of an aircraft that had a passenger on board who is suspected of being infected with one of the mentioned diseases. Although, basic advice on hygiene and sanitation on board an aircraft is given by the World Health Organization, these guidelines lack details on available and effective substances as well as standardized operating procedures (SOP). The purpose of this paper is to give guidance on the choice of substances that were tested by a laboratory of Lufthansa Technik and found compatible with aircraft components, as well as to describe procedures which ensure a safe and efficient disinfection of civil aircrafts. This guidance and the additional SOPs are made public and are available as mentioned in this paper.
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Affiliation(s)
- Joachim Klaus
- Occupational Safety Flight Operations, Department FRA PX/O, Lufthansa Basis - Tor 21, Lufthansa German Airlines, 60546, Frankfurt am Main, Germany.
| | - Peter Gnirs
- Lufthansa Technik AG, Frankfurt am Main, Germany
| | | | - Angela Wirtz
- Hesse Ministry of Social Affairs and Integration, Wiesbaden, Germany
| | - Matthias Jeglitza
- Federal Ministry of Transport and Digital Infrastructure, Berlin, Germany
| | - Walter Gaber
- Fraport AG Frankfurt Airport Services Worldwide, Frankfurt am Main, Germany
| | - Rene Gottschalk
- Health Protection Authority and Competence Network for Highly Pathogenic Agents, Frankfurt am Main, Germany
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Goeijenbier M, van Genderen P, Ward BJ, Wilder-Smith A, Steffen R, Osterhaus ADME. Travellers and influenza: risks and prevention. J Travel Med 2017; 24:taw078. [PMID: 28077609 PMCID: PMC5505480 DOI: 10.1093/jtm/taw078] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/14/2016] [Indexed: 02/03/2023]
Abstract
BACKGROUND Influenza viruses are among the major causes of serious human respiratory tract infection worldwide. In line with the high disease burden attributable to influenza, these viruses play an important, but often neglected, role in travel medicine. Guidelines and recommendations regarding prevention and management of influenza in travellers are scarce. Of special interest for travel medicine are risk populations and also circumstances that facilitate influenza virus transmission and spread, like travel by airplane or cruise ship and mass gatherings. METHODS We conducted a PUBMED/MEDLINE search for a combination of the MeSH terms Influenza virus, travel, mass gathering, large scale events and cruise ship. In addition we gathered guidelines and recommendations from selected countries and regarding influenza prevention and management in travellers. By reviewing these search results in the light of published knowledge in the fields of influenza prevention and management, we present best practice advice for the prevention and management of influenza in travel medicine. RESULTS Seasonal influenza is among the most prevalent infectious diseases in travellers. Known host-associated risk factors include extremes of age and being immune-compromised, while the most relevant environmental factors are associated with holiday cruises and mass gatherings. CONCLUSIONS Pre-travel advice should address influenza and its prevention for travellers, whenever appropriate on the basis of the epidemiological situation concerned. Preventative measures should be strongly recommended for travellers at high-risk for developing complications. In addition, seasonal influenza vaccination should be considered for any traveller wishing to reduce the risk of incapacitation, particularly cruise ship crew and passengers, as well as those participating in mass gatherings. Besides advice concerning preventive measures and vaccination, advice on the use of antivirals may be considered for some travellers.
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Affiliation(s)
- M Goeijenbier
- Institute for Tropical Diseases, Havenziekenhuis, Rotterdam, The Netherlands
| | - P van Genderen
- Institute for Tropical Diseases, Havenziekenhuis, Rotterdam, The Netherlands
| | - B J Ward
- Research institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - A Wilder-Smith
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
- Institute of Public Health, University of Heidelberg, Germany
| | - R Steffen
- Epidemiology, Biostatistics and Prevention Institute, WHO Collaborating Centre for Travelers Health, University of Zurich Travel Health Centre, Zurich, Switzerland
| | - A D M E Osterhaus
- ARTEMIS One Health Research Institute Utrecht, The Netherlands
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine, Hannover, Germany
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Browne A, Ahmad SSO, Beck CR, Nguyen-Van-Tam JS. The roles of transportation and transportation hubs in the propagation of influenza and coronaviruses: a systematic review. J Travel Med 2016; 23:tav002. [PMID: 26782122 PMCID: PMC7539332 DOI: 10.1093/jtm/tav002] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/10/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND Respiratory viruses spread in humans across wide geographical areas in short periods of time, resulting in high levels of morbidity and mortality. We undertook a systematic review to assess the evidence that air, ground and sea mass transportation systems or hubs are associated with propagating influenza and coronaviruses. METHODS Healthcare databases and sources of grey literature were searched using pre-defined criteria between April and June 2014. Two reviewers screened all identified records against the protocol, undertook risk of bias assessments and extracted data using a piloted form. Results were analysed using a narrative synthesis. RESULTS Forty-one studies met the eligibility criteria. Risk of bias was high in the observational studies, moderate to high in the reviews and moderate to low in the modelling studies. In-flight influenza transmission was identified substantively on five flights with up to four confirmed and six suspected secondary cases per affected flight. Five studies highlighted the role of air travel in accelerating influenza spread to new areas. Influenza outbreaks aboard cruise ships affect 2-7% of passengers. Influenza transmission events have been observed aboard ground transport vehicles. High heterogeneity between studies and the inability to exclude other sources of infection means that the risk of influenza transmission from an index case to other passengers cannot be accurately quantified. A paucity of evidence was identified describing severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus transmission events associated with transportation systems or hubs. CONCLUSION Air transportation appears important in accelerating and amplifying influenza propagation. Transmission occurs aboard aeroplanes, at the destination and possibly at airports. Control measures to prevent influenza transmission on cruise ships are needed to reduce morbidity and mortality. There is no recent evidence of sea transport accelerating influenza or coronavirus spread to new areas. Further investigation is required regarding the roles of ground transportation systems and transport hubs in pandemic situations.
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Affiliation(s)
- Annie Browne
- Division of Epidemiology and Public Health, University of Nottingham, Nottingham, UK, Field Epidemiology Service, Public Health England, Bristol, UK and
| | - Sacha St-Onge Ahmad
- Division of Epidemiology and Public Health, University of Nottingham, Nottingham, UK
| | - Charles R Beck
- Field Epidemiology Service, Public Health England, Bristol, UK and School of Social and Community Medicine, University of Bristol, Bristol, UK
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Priest PC, Jennings LC, Duncan AR, Brunton CR, Baker MG. Effectiveness of border screening for detecting influenza in arriving airline travelers. Am J Public Health 2015; 105 Suppl 4:S607-13, S600-6. [PMID: 26313050 DOI: 10.2105/ajph.2012.300761r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES We measured symptom and influenza prevalence, and the effectiveness of symptom and temperature screening for identifying influenza, in arriving international airline travelers. METHODS This cross-sectional study collected data from travelers to Christchurch International Airport, New Zealand, in winter 2008, via a health questionnaire, temperature testing, and respiratory sampling. RESULTS Forms were returned by 15 976 (68%) travelers. Of these, 17% reported at least 1 influenza symptom, with runny or blocked nose (10%) and cough (8%) most common. Respiratory specimens were obtained from 3769 travelers. Estimated prevalence of influenza was 1.1% (4% among symptomatic, 0.2% among asymptomatic). The sensitivity of screening criteria ranged from 84% for "any symptom" to 3% for a fever of 37.8 °C or greater. The positive predictive value was low for all criteria. CONCLUSIONS Border screening using self-reported symptoms and temperature testing has limitations for preventing pandemic influenza from entering a country. Using "any symptom" or cough would lead to many uninfected people being investigated, yet some infected people would remain undetected. If more specific criteria such as fever were used, most infected people would enter the country despite screening.
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Affiliation(s)
- Patricia C Priest
- Patricia C. Priest is with the Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand. Lance C. Jennings is with the Department of Pathology, University of Otago Christchurch and Canterbury Health Laboratories, Christchurch, New Zealand. Alasdair R. Duncan and Cheryl R. Brunton are with the Department of Public Health and General Practice, University of Otago Christchurch. Michael G. Baker is with the Department of Public Health, University of Otago Wellington, Wellington, New Zealand
| | - Lance C Jennings
- Patricia C. Priest is with the Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand. Lance C. Jennings is with the Department of Pathology, University of Otago Christchurch and Canterbury Health Laboratories, Christchurch, New Zealand. Alasdair R. Duncan and Cheryl R. Brunton are with the Department of Public Health and General Practice, University of Otago Christchurch. Michael G. Baker is with the Department of Public Health, University of Otago Wellington, Wellington, New Zealand
| | - Alasdair R Duncan
- Patricia C. Priest is with the Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand. Lance C. Jennings is with the Department of Pathology, University of Otago Christchurch and Canterbury Health Laboratories, Christchurch, New Zealand. Alasdair R. Duncan and Cheryl R. Brunton are with the Department of Public Health and General Practice, University of Otago Christchurch. Michael G. Baker is with the Department of Public Health, University of Otago Wellington, Wellington, New Zealand
| | - Cheryl R Brunton
- Patricia C. Priest is with the Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand. Lance C. Jennings is with the Department of Pathology, University of Otago Christchurch and Canterbury Health Laboratories, Christchurch, New Zealand. Alasdair R. Duncan and Cheryl R. Brunton are with the Department of Public Health and General Practice, University of Otago Christchurch. Michael G. Baker is with the Department of Public Health, University of Otago Wellington, Wellington, New Zealand
| | - Michael G Baker
- Patricia C. Priest is with the Department of Preventive and Social Medicine, University of Otago, Dunedin, New Zealand. Lance C. Jennings is with the Department of Pathology, University of Otago Christchurch and Canterbury Health Laboratories, Christchurch, New Zealand. Alasdair R. Duncan and Cheryl R. Brunton are with the Department of Public Health and General Practice, University of Otago Christchurch. Michael G. Baker is with the Department of Public Health, University of Otago Wellington, Wellington, New Zealand
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Priest PC, Jennings LC, Duncan AR, Brunton CR, Baker MG. Eficacia de la detección sistemática de la gripe en las fronteras en los viajeros que llegan por vía aérea. Am J Public Health 2015. [DOI: 10.2105/ajph.2012.300761s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Objetivos. Se midieron los síntomas y la prevalencia de la gripe (también llamada influenza), así como la eficacia del mecanismo de detección sistemática basado en los síntomas y la temperatura para diagnosticar la gripe en viajeros internacionales que llegaban por vía aérea. Métodos. El presente estudio transversal recopiló datos de viajeros que llegaron al aeropuerto internacional de Christchurch (Nueva Zelandia) en el invierno del 2008 mediante un cuestionario de salud, medición de la temperatura y toma de muestras de las vías respiratorias. Resultados. De los viajeros, 15 976 (68%) entregaron los formularios completos. De ellos, 17% notificaron al menos un síntoma de gripe; los síntomas más comunes fueron rinorrea o congestión nasal (10%) y tos (8%). Se tomaron muestras de las vías respiratorias de 3 769 viajeros. La prevalencia estimada de la gripe fue de 1,1% (4% en las personas sintomáticas, 0,2% en las asintomáticas). La sensibilidad de los criterios de detección varió de 84% para “cualquier síntoma” a 3% para la fiebre de 37,8 °C o mayor. El valor predictivo positivo fue bajo para todos los criterios. Conclusiones. El método de detección sistemática en las fronteras mediante la autonotificación de síntomas y la toma de la temperatura presenta limitaciones para impedir que una gripe pandémica entre en un país. Basarse en criterios como “cualquier síntoma” o la tos haría que se investigara a varias personas no infectadas, mientras que algunas personas infectadas pasarían inadvertidas. Si se usaran criterios más específicos como la fiebre, la mayoría de las personas infectadas entrarían en el país a pesar del mecanismo de detección.
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Affiliation(s)
- Patricia C. Priest
- Patricia C. Priest, DPhil, MPH, MBChB, Departamento de Medicina Preventiva y Social, Universidad de Otago, Dunedin, Nueva Zelandia. La correspondencia se debe dirigir a Patricia Priest,
- Lance C. Jennings, PhD, MSc, BSc, Departamento de Anatomía Patológica, Laboratorios de Salud de la Universidad de Otago en Christchurch y Canterbury, Christchurch, Nueva Zelandia
- Alasdair R. Duncan, MPH, BSc, y Cheryl R. Brunton, MBChB, DipComH, Departamento de Salud Pública y Práctica General, Universidad de Otago en Christchurch, Nueva Zelandia
- Michael G. Baker, MBChB, DPH, Departamento de Salud Pública, Universidad de Otago en Wellington, Wellington, Nueva Zelandia
| | - Lance C. Jennings
- Patricia C. Priest, DPhil, MPH, MBChB, Departamento de Medicina Preventiva y Social, Universidad de Otago, Dunedin, Nueva Zelandia. La correspondencia se debe dirigir a Patricia Priest,
- Lance C. Jennings, PhD, MSc, BSc, Departamento de Anatomía Patológica, Laboratorios de Salud de la Universidad de Otago en Christchurch y Canterbury, Christchurch, Nueva Zelandia
- Alasdair R. Duncan, MPH, BSc, y Cheryl R. Brunton, MBChB, DipComH, Departamento de Salud Pública y Práctica General, Universidad de Otago en Christchurch, Nueva Zelandia
- Michael G. Baker, MBChB, DPH, Departamento de Salud Pública, Universidad de Otago en Wellington, Wellington, Nueva Zelandia
| | - Alasdair R. Duncan
- Patricia C. Priest, DPhil, MPH, MBChB, Departamento de Medicina Preventiva y Social, Universidad de Otago, Dunedin, Nueva Zelandia. La correspondencia se debe dirigir a Patricia Priest,
- Lance C. Jennings, PhD, MSc, BSc, Departamento de Anatomía Patológica, Laboratorios de Salud de la Universidad de Otago en Christchurch y Canterbury, Christchurch, Nueva Zelandia
- Alasdair R. Duncan, MPH, BSc, y Cheryl R. Brunton, MBChB, DipComH, Departamento de Salud Pública y Práctica General, Universidad de Otago en Christchurch, Nueva Zelandia
- Michael G. Baker, MBChB, DPH, Departamento de Salud Pública, Universidad de Otago en Wellington, Wellington, Nueva Zelandia
| | - Cheryl R. Brunton
- Patricia C. Priest, DPhil, MPH, MBChB, Departamento de Medicina Preventiva y Social, Universidad de Otago, Dunedin, Nueva Zelandia. La correspondencia se debe dirigir a Patricia Priest,
- Lance C. Jennings, PhD, MSc, BSc, Departamento de Anatomía Patológica, Laboratorios de Salud de la Universidad de Otago en Christchurch y Canterbury, Christchurch, Nueva Zelandia
- Alasdair R. Duncan, MPH, BSc, y Cheryl R. Brunton, MBChB, DipComH, Departamento de Salud Pública y Práctica General, Universidad de Otago en Christchurch, Nueva Zelandia
- Michael G. Baker, MBChB, DPH, Departamento de Salud Pública, Universidad de Otago en Wellington, Wellington, Nueva Zelandia
| | - Michael G. Baker
- Patricia C. Priest, DPhil, MPH, MBChB, Departamento de Medicina Preventiva y Social, Universidad de Otago, Dunedin, Nueva Zelandia. La correspondencia se debe dirigir a Patricia Priest,
- Lance C. Jennings, PhD, MSc, BSc, Departamento de Anatomía Patológica, Laboratorios de Salud de la Universidad de Otago en Christchurch y Canterbury, Christchurch, Nueva Zelandia
- Alasdair R. Duncan, MPH, BSc, y Cheryl R. Brunton, MBChB, DipComH, Departamento de Salud Pública y Práctica General, Universidad de Otago en Christchurch, Nueva Zelandia
- Michael G. Baker, MBChB, DPH, Departamento de Salud Pública, Universidad de Otago en Wellington, Wellington, Nueva Zelandia
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Tang JW, Wilson P, Shetty N, Noakes CJ. Aerosol-Transmitted Infections-a New Consideration for Public Health and Infection Control Teams. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2015; 7:176-201. [PMID: 32226323 PMCID: PMC7100085 DOI: 10.1007/s40506-015-0057-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Since the emergence of the 2003 severe acute respiratory syndrome (SARS), the 2003 reemergence of avian A/H5N1, the emergence of the 2009 pandemic influenza A/H1N1, the 2012 emergence of Middle East respiratory syndrome (MERS), the 2013 emergence of avian A/H7N9 and the 2014 Ebola virus outbreaks, the potential for the aerosol transmission of infectious agents is now routinely considered in the investigation of any outbreak. Although many organisms have traditionally been considered to be transmitted by only one route (e.g. direct/indirect contact and/or faecal-orally), it is now apparent that the aerosol transmission route is also possible and opportunistic, depending on any potentially aerosol-generating procedures, the severity of illness and the degree and duration of pathogen-shedding in the infected patient, as well as the environment in which these activities are conducted.This article reviews the evidence and characteristics of some of the accepted (tuberculosis, measles, chickenpox, whooping cough) and some of the more opportunistic (influenza, Clostridium difficile, norovirus) aerosol-transmitted infectious agents and outlines methods of detecting and quantifying transmission.
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Affiliation(s)
- Julian W. Tang
- Clinical Microbiology, Leicester Royal Infirmary, University Hospitals Leicester, Leicester NHS Trust, Leicester, LE1 5WW UK
| | - Peter Wilson
- Clinical Microbiology, University College London Hospitals NHS Trust, London, UK
| | - Nandini Shetty
- Clinical Microbiology, University College London Hospitals NHS Trust, London, UK
| | - Catherine J. Noakes
- Institute for Public Health and Environmental Engineering, School of Civil Engineering, University of Leeds, Leeds, UK
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Jennings LC, Priest PC, Psutka RA, Duncan AR, Anderson T, Mahagamasekera P, Strathdee A, Baker MG. Respiratory viruses in airline travellers with influenza symptoms: Results of an airport screening study. J Clin Virol 2015; 67:8-13. [PMID: 25959149 PMCID: PMC7106445 DOI: 10.1016/j.jcv.2015.03.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 03/08/2015] [Accepted: 03/12/2015] [Indexed: 01/25/2023]
Abstract
A symptom screening tool was used at the border to predict which travellers were more likely to have respiratory virus infections. The most frequently identified viruses were rhinoviruses, enteroviruses and influenza B. The positive predictive value (PPV) of any symptom for any respiratory virus infection was low at 26%. There was a substantial overlap in the symptom profiles between the respiratory viruses found in the study participants. It is unlikely that clinical symptoms alone can be used to predict infections with specific respiratory viruses.
Background There is very little known about the prevalence and distribution of respiratory viruses, other than influenza, in international air travellers and whether symptom screening would aid in the prediction of which travellers are more likely to be infected with specific respiratory viruses. Objectives In this study, we investigate whether, the use of a respiratory symptom screening tool at the border would aid in predicting which travellers are more likely to be infected with specific respiratory viruses. Study design Data were collected from travellers arriving at Christchurch International Airport, New Zealand, during the winter 2008, via a symptom questionnaire, temperature testing, and respiratory sampling. Results Respiratory viruses were detected in 342 (26.0%) of 1313 samples obtained from 2714 symptomatic travellers. The most frequently identified viruses were rhinoviruses (128), enteroviruses (77) and influenza B (48). The most frequently reported symptoms were stuffy or runny nose (60%), cough (47%), sore throat (27%) and sneezing (24%). Influenza B infections were associated with the highest number of symptoms (mean of 3.4) followed by rhinoviruses (mean of 2.2) and enteroviruses (mean of 1.9). The positive predictive value (PPV) of any symptom for any respiratory virus infection was low at 26%. Conclusions The high prevalence of respiratory virus infections caused by viruses other than influenza in this study, many with overlapping symptotology to influenza, has important implications for any screening strategies for the prediction of influenza in airline travellers.
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Affiliation(s)
- Lance C Jennings
- Virology Section, Canterbury Health Laboratories, and Pathology Department, University of Otago, Christchurch 8011, New Zealand.
| | - Patricia C Priest
- Department of Preventive and Social Medicine, University of Otago, Dunedin 9054, New Zealand
| | - Rebecca A Psutka
- Department of Preventive and Social Medicine, University of Otago, Dunedin 9054, New Zealand
| | - Alasdair R Duncan
- Planning and Funding, Canterbury District Health, Christchurch 8011, New Zealand
| | - Trevor Anderson
- Virology Section, Canterbury Health Laboratories, Christchurch 8011, New Zealand
| | | | - Andrew Strathdee
- Virology Section, Canterbury Health Laboratories, Christchurch 8011, New Zealand
| | - Michael G Baker
- Department of Public Health, University of Otago, Wellington 6242, New Zealand
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Shankar AG, Janmohamed K, Olowokure B, Smith GE, Hogan AH, De Souza V, Wallensten A, Oliver I, Blatchford O, Cleary P, Ibbotson S. Contact tracing for influenza A(H1N1)pdm09 virus-infected passenger on international flight. Emerg Infect Dis 2014; 20:118-20. [PMID: 24377724 PMCID: PMC3884702 DOI: 10.3201/eid2001.120101] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In April 2009, influenza A(H1N1)pdm09 virus infection was confirmed in a person who had been symptomatic while traveling on a commercial flight from Mexico to the United Kingdom. Retrospective public health investigation and contact tracing led to the identification of 8 additional confirmed cases among passengers and community contacts of passengers.
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Young N, Pebody R, Smith G, Olowokure B, Shankar G, Hoschler K, Galiano M, Green H, Wallensten A, Hogan A, Oliver I. International flight-related transmission of pandemic influenza A(H1N1)pdm09: an historical cohort study of the first identified cases in the United Kingdom. Influenza Other Respir Viruses 2013; 8:66-73. [PMID: 24373291 PMCID: PMC4177799 DOI: 10.1111/irv.12181] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2013] [Indexed: 12/01/2022] Open
Abstract
Background Transporting over two billion passengers per year, global airline travel has the potential to spread emerging infectious diseases, both via transportation of infectious cases and through in-flight transmission. Current World Health Organization (WHO) guidance recommends contact tracing of passengers seated within two rows of a case of influenza during air travel. Objectives The objectives of this study were to describe flight-related transmission of influenza A(H1N1)pdm09 during a commercial flight carrying the first cases reported in the United Kingdom and to test the specific hypothesis that passengers seated within two rows of an infectious case are at greater risk of infection. Methods An historical cohort study, supplemented by contact tracing, enhanced surveillance data and laboratory testing, was used to establish a case status for passengers on board the flight. Results Data were available for 239 of 278 (86·0%) of passengers on the flight, of whom six were considered infectious in-flight and one immune. The attack rate (AR) was 10 of 232 (4·3%; 95% CI 1·7–6·9%). There was no evidence that the AR for those seated within two rows of an infectious case was different from those who were not (relative risk 0·9; 95% CI 0·2–3·1; P = 1·00). Laboratory testing using PCR and/or serology, available for 118 of 239 (49·4%) of the passengers, was largely consistent with clinically defined case status. Conclusions This study of A(H1N1)pdm09 does not support current WHO guidance regarding the contact tracing of passengers seated within two rows of an infectious case of influenza during air travel.
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Abstract
The threat of a virulent, highly transmissible pandemic virus has motivated an escalating research effort to identify the transmissible genotypes of animal viruses that cross over into the human population (animal–human transmission) and sustain human–human transmission. In addition to the pursuit of the viral genotype, a greater understanding of the host-virus phenotype of infectiousness, transmissibility and susceptibility will be required. This review examines experimental animal transmission of influenza for insights into human influenza transmission. Transmission is viewed as sequential steps that the virus must pass critical thresholds to achieve transmission and ultimately survival in the human host. In particular, a quantitative understanding in animal models of viral replication efficiency, airway viral load, exhaled viral aerosol load, environmental virus survival and host susceptibility will likely yield important insights. Computational modeling will enhance animal model data, as well as guide the use of pandemic mitigation strategies.
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Affiliation(s)
- Frederick Koster
- Department of Computer Science, University of New Mexico, Albuquerque, NM, USA and The Lovelace Respiratory Research Institute, Albuquerque, NM, USA
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Zhang L, Peng Z, Ou J, Zeng G, Fontaine RE, Liu M, Cui F, Hong R, Zhou H, Huai Y, Chuang SK, Leung YH, Feng Y, Luo Y, Shen T, Zhu BP, Widdowson MA, Yu H. Protection by face masks against influenza A(H1N1)pdm09 virus on trans-Pacific passenger aircraft, 2009. Emerg Infect Dis 2013; 19. [PMID: 23968983 PMCID: PMC3810906 DOI: 10.3201/eid1909.121765] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
In response to several influenza A(H1N1)pdm09 infections that developed in passengers after they traveled on the same 2 flights from New York, New York, USA, to Hong Kong, China, to Fuzhou, China, we assessed transmission of influenza A(H1N1)pdm09 virus on these flights. We defined a case of infection as onset of fever and respiratory symptoms and detection of virus by PCR in a passenger or crew member of either flight. Illness developed only in passengers who traveled on the New York to Hong Kong flight. We compared exposures of 9 case-passengers with those of 32 asymptomatic control-passengers. None of the 9 case-passengers, compared with 47% (15/32) of control-passengers, wore a face mask for the entire flight (odds ratio 0, 95% CI 0-0.71). The source case-passenger was not identified. Wearing a face mask was a protective factor against influenza infection. We recommend a more comprehensive intervention study to accurately estimate this effect.
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Affiliation(s)
- Lijie Zhang
- Chinese Center for Disease Control and Prevention, Beijing, China
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Priest PC, Jennings LC, Duncan AR, Brunton CR, Baker MG. Effectiveness of border screening for detecting influenza in arriving airline travelers. Am J Public Health 2012; 103:1412-8. [PMID: 23237174 DOI: 10.2105/ajph.2012.300761] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES We measured symptom and influenza prevalence, and the effectiveness of symptom and temperature screening for identifying influenza, in arriving international airline travelers. METHODS This cross-sectional study collected data from travelers to Christchurch International Airport, New Zealand, in winter 2008, via a health questionnaire, temperature testing, and respiratory sampling. RESULTS Forms were returned by 15 976 (68%) travelers. Of these, 17% reported at least 1 influenza symptom, with runny or blocked nose (10%) and cough (8%) most common. Respiratory specimens were obtained from 3769 travelers. Estimated prevalence of influenza was 1.1% (4% among symptomatic, 0.2% among asymptomatic). The sensitivity of screening criteria ranged from 84% for "any symptom" to 3% for a fever of 37.8 °C or greater. The positive predictive value was low for all criteria. CONCLUSIONS Border screening using self-reported symptoms and temperature testing has limitations for preventing pandemic influenza from entering a country. Using "any symptom" or cough would lead to many uninfected people being investigated, yet some infected people would remain undetected. If more specific criteria such as fever were used, most infected people would enter the country despite screening.
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Affiliation(s)
- Patricia C Priest
- Department of Preventive and Social Medicine, University of Otago, PO Box 913, Dunedin 9054, New Zealand.
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Chowell G, Nishiura H, Viboud C. Modeling rapidly disseminating infectious disease during mass gatherings. BMC Med 2012; 10:159. [PMID: 23217051 PMCID: PMC3532170 DOI: 10.1186/1741-7015-10-159] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 12/07/2012] [Indexed: 11/25/2022] Open
Abstract
We discuss models for rapidly disseminating infectious diseases during mass gatherings (MGs), using influenza as a case study. Recent innovations in modeling and forecasting influenza transmission dynamics at local, regional, and global scales have made influenza a particularly attractive model scenario for MG. We discuss the behavioral, medical, and population factors for modeling MG disease transmission, review existing model formulations, and highlight key data and modeling gaps related to modeling MG disease transmission. We argue that the proposed improvements will help integrate infectious-disease models in MG health contingency plans in the near future, echoing modeling efforts that have helped shape influenza pandemic preparedness plans in recent years.
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Affiliation(s)
- Gerardo Chowell
- School of Human Evolution and Social Change, Arizona State University, 900 S. Cady Mall, Tempe, AZ 85287-2402, USA.
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Graf J, Stüben U, Pump S. In-flight medical emergencies. DEUTSCHES ARZTEBLATT INTERNATIONAL 2012; 109:591-601; quiz 602. [PMID: 23093989 DOI: 10.3238/arztebl.2012.0591] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 07/25/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND One in every 10 000 to 40 000 passengers on commercial aircraft will have a medical incident while on board. Many physicians are unaware of the special features of the cabin atmosphere, the medical equipment available on airplanes, and the resulting opportunities for medical intervention. METHODS A selective literature search was performed and supplemented with international recommendations and guidelines and with data from the Lufthansa registry. RESULTS Data on in-flight medical emergencies have been collected in various ways, with varying results; it is generally agreed, however, that the more common incidents include gastrointestinal conditions (diarrhea, nausea, vomiting), circulatory collapse, hypertension, stroke, and headache (including migraine). Data from the Lufthansa registry for the years 2010 and 2011 reveal the rarity of cardiopulmonary resuscitation (mean: 8 cases per year), death (12 cases per year), childbirth (1 case per year), and psychiatric incidents (81 cases per year). If one assumes that one medical incident arises for every 10 000 passengers, and that there are 400 passengers on board each flight, then one can calculate that the probability of experiencing at least one medical incident reaches 95% after 24 intercontinental flights. CONCLUSION An in-flight medical emergency is an exceptional event for the physician and all other persons involved. Physician passengers can act more effectively if they are aware of the framework conditions, the available medical equipment, and the commonly encountered medical conditions.
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Affiliation(s)
- Jürgen Graf
- Lufthansa Medical Service, Frankfurt am Main, Germany.
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Castilla J, Godoy P, Domínguez Á, Martín V, Delgado-Rodríguez M, Martínez-Baz I, Baricot M, Soldevila N, Mayoral JM, Astray J, Quintana JM, Cantón R, Castro A, González-Candelas F, Alonso J, Saez M, Tamames S, Pumarola T. Risk factors and effectiveness of preventive measures against influenza in the community. Influenza Other Respir Viruses 2012; 7:177-83. [PMID: 22458533 PMCID: PMC5780759 DOI: 10.1111/j.1750-2659.2012.00361.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Please cite this paper as: Castilla et al. (2013) Risk factors and effectiveness of preventive measures against influenza in the community. Influenza and Other Respiratory Viruses 7(2) 177–183. Background The role of different risk exposures and preventive measures against influenza has not been well established. Objective The aim of this study was to evaluate risk factors and measures to prevent influenza infection in the community. Methods We conducted a multicenter case–control study. Cases were 481 outpatients aged 18 years or older with laboratory‐confirmed influenza A(H1N1)09 in the 2009–2010 season in Spain. A control was selected for each case from outpatients from the same area matched by age and date of consultation. Information on risk situations, preventive measures and other variables was obtained by interview and review of the medical record. Results In the multivariate conditional logistic regression analysis, the risk of a diagnosis of influenza increased with the number of cohabitants (compared with <3 cohabitants, three cohabitants had an OR = 1·80, 95% CI 1·12–2·89, and ≥5 cohabitants had an OR = 2·66, 95% CI 1·31–5·41) and for health care workers (OR = 2·94, 95% CI 1·53–5·66). The use of metropolitan public transport was associated with a lower frequency of a diagnosis of influenza (OR = 0·45, 95% CI 0·30–0·68) but not the use of taxis or long‐distance transport. The influenza A(H1N1)09 vaccine had a protective effect (OR = 0·13, 95% CI 0·04–0·48), unlike hand washing after touching contaminated surfaces or the use of alcohol‐based hand sanitizers. Conclusion The home environment appears to play an important role in the spread of influenza in adults, but not the use of public transport. Health care workers have a higher risk of contracting influenza. Vaccination was the most effective preventive measure.
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Affiliation(s)
- Jesús Castilla
- Instituto de Salud Pública de Navarra, 31003 Pamplona, Spain.
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Sakaguchi H, Tsunoda M, Wada K, Ohta H, Kawashima M, Yoshino Y, Aizawa Y. Assessment of border control measures and community containment measures used in Japan during the early stages of Pandemic (H1N1) 2009. PLoS One 2012; 7:e31289. [PMID: 22355354 PMCID: PMC3280294 DOI: 10.1371/journal.pone.0031289] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 01/05/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In the early stages of Pandemic (H1N1) 2009, border control measures were taken by quarantine stations to block the entry of infected individuals into Japan and community containment measures were implemented to prevent the spreading. The objectives of this study were to describe these measures and the characteristics of infected individuals, and to assess the measures' effectiveness. METHODOLOGY/PRINCIPAL FINDINGS Border control and community containment measures implemented from April to June (Period I: April 28-May 21, Period II: May 22-June 18) 2009 were described. Number of individuals identified and disease characteristics were analyzed. For entry screening, a health declaration form and an infrared thermoscanner were used to detect symptomatic passengers. Passengers indicated for the rapid influenza test underwent the test followed by RT-PCR. Patients positive for H1N1 were isolated, and close contacts were quarantined. Entry cards were handed out to all asymptomatic passengers informing them about how to contact a health center in case they developed symptoms. Nine individuals were identified by entry screening and 1 during quarantine to have Pandemic (H1N1) 2009. Health monitoring by health centers was performed in period I for passengers arriving from affected countries and in period II for those who had come into contact with the individuals identified by entry screening. Health monitoring identified 3 infected individuals among 129,546 in Period I and 5 among 746 in Period II. Enhanced surveillance, which included mandatory reporting of details of the infected individuals, identified 812 individuals, 141 (18%) of whom had a history of international travel. Twenty-four of these 141 passengers picked up by enhanced surveillance had been developing symptoms on entry and were missed at screening. CONCLUSION/SIGNIFICANCE Symptomatic passengers were detected by the various entry screening measures put in place. Enhanced surveillance provided data for the improvement of public health measures in future pandemics.
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Affiliation(s)
- Hiroko Sakaguchi
- Department of Occupational Health, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Masashi Tsunoda
- Department of Preventive Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Koji Wada
- Department of Public Health, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Hiroshi Ohta
- Department of Public Health, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Masatoshi Kawashima
- Department of Occupational Health, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Yae Yoshino
- Department of Occupational Health, Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Yoshiharu Aizawa
- Department of Preventive Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
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