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2.
Travel Med Infect Dis ; 47: 102313, 2022.
Article in English | MEDLINE | ID: covidwho-1740219

ABSTRACT

BACKGROUND: Despite commercial airlines mandating masks, there have been multiple documented events of COVID-19 superspreading on flights. Conventional models do not adequately explain superspreading patterns on flights, with infection spread wider than expected from proximity based on passenger seating. An important reason for this is that models typically do not consider the movement of passengers during the flight, boarding, or deplaning. Understanding the risks for each of these aspects could provide insight into effective mitigation measures. METHODS: We modeled infection risk from seating and fine-grained movement patterns - boarding, deplaning, and inflight movement. We estimated infection model parameters from a prior superspreading event. We validated the model and the impact of interventions using available data from three flights, including cabin layout and seat locations of infected and uninfected passengers, to suggest interventions to mitigate COVID-19 superspreading events during air travel. Specifically, we studied: 1) London to Hanoi with 201 passengers, including 13 secondary infections among passengers; 2) Singapore to Hangzhou with 321 passengers, including 12 to 14 secondary infections; 3) a non-superspreading event on a private jet in Japan with 9 passengers and no secondary infections. RESULTS: Our results show that the inclusion of passenger movement better explains the infection spread patterns than conventional models do. We also found that FFP2/N95 mask usage would have reduced infection by 95-100%, while cloth masks would have reduced it by only 40-80%. Results indicate that leaving the middle seat vacant is effective in reducing infection, and the effectiveness increases when combined with good quality masks. However, with a good mask, the risk is quite low even without the middle seats being empty. CONCLUSIONS: Our results suggest the need for more stringent guidelines to reduce aviation-related superspreading events of COVID-19.


Subject(s)
Air Travel , COVID-19 , Coinfection , Aircraft , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Movement
3.
Pharmaceut Med ; 36(2): 131-142, 2022 04.
Article in English | MEDLINE | ID: covidwho-1712377

ABSTRACT

BACKGROUND: Many in-person congresses have shifted to a virtual format owing to coronavirus disease 2019 (COVID-19). We assessed carbon emissions savings associated with virtual attendance at international medical congresses for a mid-sized pharmaceutical company, to identify which aspects are driving the carbon cost. METHODS: We assessed carbon emissions that were the responsibility of company attendees (including their guests) for the most attended congresses by employees (American Society of Clinical Oncology [ASCO], European Neuroendocrine Tumor Society [ENETS], European Society for Medical Oncology [ESMO], World Congress for NeuroRehabilitation [WCNR]). For in-person estimates, we considered travel, accommodation and congress attendance; for online estimates, we considered office and internet-related energy use. Emissions were defined using recognised data sources. RESULTS: For 1723 anticipated in-person attendees, calculated total carbon emissions were 3,262,574 kgCO2e (mean per in-person company attendee, 1894 kgCO2e: ASCO, 4172; ESMO, 1479; WCNR, 1153; ENETS, 1009). For context, the average UK resident's annual carbon footprint is 5600 kgCO2e. Travel accounted for 91-96% of total emissions, mainly through long distance and business-class air travel. Calculated total carbon emissions associated with 1839 virtual attendees were 19,095 kgCO2e (mean per virtual company attendee, 10.4 kgCO2e; equivalent to approximately 0.3-1.1% of in-person attendance emissions across all four congresses assessed). CONCLUSION: Carbon emissions associated with virtual attendance were two orders of magnitude lower than for in-person attendance, and therefore the benefits of in-person attendance at medical congresses must be balanced against the carbon cost. Due diligence around who should attend and how they should travel to face-to-face meetings, and consideration of hybrid and domestic satellite options could be part of a balanced solution to reducing carbon emissions.


Subject(s)
Air Travel , COVID-19 , Carbon , Drug Industry , Humans , Pandemics
5.
Mayo Clin Proc ; 96(11): 2856-2860, 2021 11.
Article in English | MEDLINE | ID: covidwho-1492385

ABSTRACT

Although there have been several case reports and simulation models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission associated with air travel, there are limited data to guide testing strategy to minimize the risk of SARS-CoV-2 exposure and transmission onboard commercial aircraft. Among 9853 passengers with a negative SARS-CoV-2 polymerase chain reaction test performed within 72 hours of departure from December 2020 through May 2021, five (0.05%) passengers with active SARS-CoV-2 infection were identified with rapid antigen tests and confirmed with rapid molecular test performed before and after an international flight from the United States to Italy. This translates to a case detection rate of 1 per 1970 travelers during a time of high prevalence of active infection in the United States. A negative molecular test for SARS-CoV-2 within 72 hours of international airline departure results in a low probability of active infection identified on antigen testing during commercial airline flight.


Subject(s)
Air Travel , COVID-19 Testing/standards , COVID-19/diagnosis , SARS-CoV-2/isolation & purification , COVID-19/transmission , COVID-19 Nucleic Acid Testing/standards , Humans , Italy , Risk Assessment , United States
7.
Nature ; 600(7887): 127-132, 2021 12.
Article in English | MEDLINE | ID: covidwho-1483136

ABSTRACT

Considerable uncertainty surrounds the timeline of introductions and onsets of local transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) globally1-7. Although a limited number of SARS-CoV-2 introductions were reported in January and February 2020 (refs.8,9), the narrowness of the initial testing criteria, combined with a slow growth in testing capacity and porous travel screening10, left many countries vulnerable to unmitigated, cryptic transmission. Here we use a global metapopulation epidemic model to provide a mechanistic understanding of the early dispersal of infections and the temporal windows of the introduction of SARS-CoV-2 and onset of local transmission in Europe and the USA. We find that community transmission of SARS-CoV-2 was likely to have been present in several areas of Europe and the USA by January 2020, and estimate that by early March, only 1 to 4 in 100 SARS-CoV-2 infections were detected by surveillance systems. The modelling results highlight international travel as the key driver of the introduction of SARS-CoV-2, with possible introductions and transmission events as early as December 2019 to January 2020. We find a heterogeneous geographic distribution of cumulative infection attack rates by 4 July 2020, ranging from 0.78% to 15.2% across US states and 0.19% to 13.2% in European countries. Our approach complements phylogenetic analyses and other surveillance approaches and provides insights that can be used to design innovative, model-driven surveillance systems that guide enhanced testing and response strategies.


Subject(s)
COVID-19/epidemiology , COVID-19/transmission , SARS-CoV-2/isolation & purification , Air Travel/statistics & numerical data , COVID-19/mortality , COVID-19/virology , China/epidemiology , Disease Outbreaks/statistics & numerical data , Europe/epidemiology , Humans , Population Density , Time Factors , United States/epidemiology
10.
Influenza Other Respir Viruses ; 16(1): 63-71, 2022 01.
Article in English | MEDLINE | ID: covidwho-1455560

ABSTRACT

BACKGROUND: Coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2), has rapidly spread globally. Potentially infected individuals travel on commercial aircraft. Thus, this study aimed to investigate and test the association between the use of face masks, physical distance, and COVID-19 among passengers and flight attendants exposed to a COVID-19 passenger in a domestic flight. METHODS: This observational study investigated passengers and flight attendants exposed to COVID-19 on March 23, 2020, on board a flight to Naha City, Japan. Secondary attack rates were calculated. Whole-genome sequencing of SARS-CoV-2 was used to identify the infectious linkage between confirmed cases in this clustering. The association between confirmed COVID-19 and proximity of passengers' seats to the index case and/or the use of face masks was estimated using logistic regression. RESULTS: Fourteen confirmed and six probable cases were identified among passengers and flight attendants. The secondary attack rate was 9.7%. Twelve of 14 SARS-CoV-2 genome sequences in confirmed cases were identical to that of the index case or showed only one nucleotide mutation. Risk factors for infection included not using a face mask (adjusted odds ratio [aOR]: 7.29, 95% confidence interval [95% CI]: 1.86-28.6), partial face mask use (aOR: 3.0, 95% CI: 0.83-10.8), and being seated within two rows from the index patient (aOR: 7.47, 95% CI: 2.06-27.2). CONCLUSION: SARS-CoV-2 was transmitted on the airplane. Nonuse of face masks was identified as an independent risk factor for contracting COVID-19 on the airplane.


Subject(s)
Air Travel , COVID-19 , Humans , Japan/epidemiology , Masks , SARS-CoV-2
12.
J Travel Med ; 28(8)2021 12 29.
Article in English | MEDLINE | ID: covidwho-1429273

ABSTRACT

BACKGROUND: A large cluster of 59 cases were linked to a single flight with 146 passengers from New Delhi to Hong Kong in April 2021. This outbreak coincided with early reports of exponential pandemic growth in New Delhi, which reached a peak of > 400 000 newly confirmed cases on 7 May 2021. METHODS: Epidemiological information including date of symptom onset, date of positive-sample detection and travel and contact history for individual cases from this flight were collected. Whole genome sequencing was performed, and sequences were classified based on the dynamic Pango nomenclature system. Maximum-likelihood phylogenetic analysis compared sequences from this flight alongside other cases imported from India to Hong Kong on 26 flights between June 2020 and April 2021, as well as sequences from India or associated with India-related travel from February to April 2021 and 1217 reference sequences. RESULTS: Sequence analysis identified six lineages of SARS-CoV-2 belonging to two variants of concern (Alpha and Delta) and one variant of public health interest (Kappa) involved in this outbreak. Phylogenetic analysis confirmed at least three independent sub-lineages of Alpha with limited onward transmission, a superspreading event comprising 37 cases of Kappa and transmission of Delta to only one passenger. Additional analysis of another 26 flights from India to Hong Kong confirmed widespread circulation of all three variants in India since early March 2021. CONCLUSIONS: The broad spectrum of disease severity and long incubation period of SARS-CoV-2 pose a challenge for surveillance and control. As illustrated by this particular outbreak, opportunistic infections of SARS-CoV-2 can occur irrespective of variant lineage, and requiring a nucleic acid test within 72 hours of departure may be insufficient to prevent importation or in-flight transmission.


Subject(s)
Air Travel , COVID-19 , Travel-Related Illness , COVID-19/epidemiology , COVID-19/transmission , Disease Outbreaks , Hong Kong , Humans , India , Phylogeny
13.
Curr Opin Infect Dis ; 34(5): 415-422, 2021 10 01.
Article in English | MEDLINE | ID: covidwho-1408785

ABSTRACT

PURPOSE OF REVIEW: To examine the literature assessing safety of air travel relating to coronavirus disease 2019 (COVID-19) transmission from January 2020 to May 2021. The COVID-19 pandemic has had an unprecedented impact on air travel and global mobility, and various efforts are being implemented to determine a safe way forward. As the pandemic evolves, so do the challenges that force various stakeholders, including the aviation industry, health authorities, and governments, to reassess and adapt their practices to ensure the safety of travellers. RECENT FINDINGS: The literature was reviewed for multiple aspects of air travel safety during the COVID-19 pandemic. Recurring themes that surfaced included the pivotal role of commercial air travel in the geographic spread of COVID-19, the efficacy of travel restrictions and quarantines, inflight transmission risk and the role of preventive measures, the utility of pre and post flight testing, the development of effective vaccines and subsequent challenges of vaccine passports, and the ongoing threat of novel highly transmissible variants. SUMMARY: Much uncertainty lies ahead within the domains of these findings, and ongoing research, discourse and review will be necessary to navigate and determine the future direction and safety of air travel. Recovery will be slow, necessitating innovative, multipronged and collaborative solutions.


Subject(s)
COVID-19/transmission , Pandemics/prevention & control , Air Travel , Humans , SARS-CoV-2/pathogenicity , Travel , Uncertainty
14.
J Travel Med ; 28(7)2021 Oct 11.
Article in English | MEDLINE | ID: covidwho-1393299

ABSTRACT

RATIONALE FOR THE REVIEW: Air travel may be associated with viruses spread via infected passengers and potentially through in-flight transmission. Given the novelty of the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, transmission associated with air travel is based on transmission dynamics of other respiratory viruses. Our objective was to provide a rapid summary and evaluation of relevant data on SARS-CoV-2 transmission aboard aircraft, report policy implications and to highlight research gaps requiring urgent attention. METHODS: We searched four electronic databases (1 February 2020-27 January 2021) and included studies on SARS-CoV-2 transmission aboard aircraft. We assessed study quality based on five criteria and reported important findings. KEY FINDINGS: We included 18 studies on in-flight SARS-CoV-2 transmission (130 unique flights) and 2 studies on wastewater from aircraft. The quality of evidence from most published studies was low. Two wastewater studies reported PCR-positive samples with high cycle threshold values (33-39). Index case definition was heterogeneous across studies. The proportion of contacts traced ranged from 0.68 to 100%. Authors traced 2800/19 729 passengers, 140/180 crew members and 8/8 medical staff. Altogether, 273 index cases were reported, with 64 secondary cases. Three studies, each investigating one flight, reported no secondary cases. Secondary attack rate among studies following up >80% of passengers and crew (including data on 10 flights) varied between 0 and 8.2%. The studies reported on the possibility of SARS-CoV-2 transmission from asymptomatic, pre-symptomatic and symptomatic individuals. Two studies performed viral cultures with 10 positive results. Genomic sequencing and phylogenetic analysis were performed in individuals from four flights. CONCLUSION: Current evidence suggests SARS-CoV-2 can be transmitted during aircraft travel, but published data do not permit any conclusive assessment of likelihood and extent. The variation in design and methodology restricts the comparison of findings across studies. Standardized guidelines for conducting and reporting future studies of transmission on aircraft should be developed.


Subject(s)
Air Travel , COVID-19 , Aircraft , Humans , Phylogeny , SARS-CoV-2 , Travel
17.
Anatol J Cardiol ; 25(Suppl 1): 34-35, 2021 08.
Article in English | MEDLINE | ID: covidwho-1380054

ABSTRACT

Air traffic has been a main vector for the global spread of COVID-19. The risk of in-flight transmission can vary widely, depending on different parameters. Therefore, implementation of measures for air travel safety is very important.


Subject(s)
Air Travel , COVID-19 , Humans , SARS-CoV-2 , Safety
18.
Ann Med ; 53(1): 1569-1575, 2021 12.
Article in English | MEDLINE | ID: covidwho-1379398

ABSTRACT

OBJECTIVES: To explore the potential of SARS-CoV-2 spread during air travel and the risk of in-flight transmission. METHODS: We enrolled all passengers and crew suspected of being infected with SARS-CoV-2, who bounded for Beijing on international flights. We specified the characteristics of all confirmed cases of COVID-19 infection and utilised Wells-Riley equation to estimate the infectivity of COVID-19 during air travel. RESULTS: We screened 4492 passengers and crew with suspected COVID-19 infection, verified 161 confirmed cases (mean age 28.6 years), and traced two confirmed cases who may have been infected in the aircraft. The estimated infectivity was 375 quanta/h (range 274-476), while the effective infectivity was only 4 quanta/h (range 2-5). The risk of per-person infection during a 13 h air travel in economy class was 0.56‰ (95% CI 0.41‰-0.72‰). CONCLUSION: We found that the universal use of face masks on the flight, together with the plane's ventilation system, significantly decreased the infectivity of COVID-19.KEY MESSAGESThe COVID-19 pandemic is changing the lifestyle in the world, especially air travel which has the potential to spread SARS-CoV-2.The universal use of face masks on the flight, together with the plane's ventilation system, significantly decreased the infectivity of COVID-19 on an aircraft.Our findings suggest that the risk of infection in aircraft was negligible.


Subject(s)
Air Travel/statistics & numerical data , COVID-19/epidemiology , Disease Transmission, Infectious/statistics & numerical data , Environmental Exposure/statistics & numerical data , COVID-19/diagnosis , COVID-19/prevention & control , Disease Transmission, Infectious/prevention & control , Female , Humans , Male , Models, Theoretical , Risk Factors , Risk Reduction Behavior , SARS-CoV-2/isolation & purification
20.
Global Health ; 17(1): 93, 2021 Aug 21.
Article in English | MEDLINE | ID: covidwho-1365366

ABSTRACT

International air travel has been highlighted as a concern since the beginning of the COVID-19 pandemic with respect to importation of cases. We summarise the available evidence for in-flight transmission of wild type SARS-CoV-2 during 2020, and for imported COVID-19 clusters to cause outbreaks. This paper provides a data baseline prior to the emergence of new mutations causing SARS-CoV-2 variants of concern, whose characteristics may increase the potential risk of in-flight transmission and imported outbreaks. The evidence on in-flight transmission of wild-type SARS-CoV-2 is limited, and is described in a small number of published reports. Most of the available evidence pertains to the early phase of the COVID-19 pandemic, during a period without non-pharmaceutical interventions such as distancing and in-flight mask wearing. There is considerable potential for outbreaks of COVID-19 from imported cases or clusters when public health guidance around quarantine of travellers and self-isolation of cases is not adhered to. Risks can be mitigated by measures such as: avoiding non-essential travel, targeted testing and quarantine of travellers from high incidence regions or regions of concern, managed quarantine processes, and protocols for rapid investigation and control of transmission from a possible variant of concern. Measures should be dynamically assessed and proportionate to the level of risk.


Subject(s)
Air Travel , COVID-19/transmission , COVID-19/virology , Communicable Diseases, Imported/epidemiology , Disease Outbreaks , COVID-19/epidemiology , Humans , SARS-CoV-2/genetics
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