Airport Screening Research Articles

Assessing exit screening of SARS-CoV-2 in Japan: an analysis of the airport screening data of passengers from the United Kingdom, 2020–2022

BackgroundJapan implemented strict border control measures and all incoming passengers were subject to entry screening with reverse transcription–polymerase chain reaction or antigen testing. From late 2020, exit screening within 72 h of departure to Japan also became mandatory. In this study, we evaluated the effectiveness of the exit screening policy in Japan by analyzing airport screening data from October 2020 to April 2022.MethodsIn addition to assessing entry screening data over time of passengers from the United Kingdom, we examined the prevalence of coronavirus disease 2019 (COVID-19) in the United Kingdom based on the Office of National Statistics infection survey. We constructed a statistical model that described entry screening positivity over time using Office of National Statistics prevalence data as the explanatory variable. Ideally, the time-dependent patterns of entry screening and Office of National Statistics prevalence data should resemble each other; however, we found that, sometimes, they were different and regarded the difference to statistically partly reflect the effectiveness of exit screening.ResultsThe average proportion positive in one month before mandatory exit screening was implemented among Japanese passengers was 0.67% (95% confidence interval [CI]: 0.45, 0.98), whereas the proportion positive decreased to 0.49% (95% CI: 0.21, 1.15) in the first month of exit screening. Adjusting for time-dependent prevalence at the origin, we concluded that exit screening contributed to reducing passenger positivity by 59.3% (95% CI: 19.6, 81.3). The overall positivity values among passengers during the Delta and Omicron variant periods were 3.46 times and 1.46 times that during the pre-Delta variant period, respectively.ConclusionsWe used a simplistic statistical model and empirical data from passengers arriving in Japan from the United Kingdom to support that exit screening helped to reduce the proportion positive by 59%. Although the proportion positive later increased considerably and precluded preventing the introduction of imported cases, submitting a certificate for a negative test result contributed to reducing the positivity among travelers.

Assessment of fever screening at airports in detecting domestic passengers infected with SARS-CoV-2, 2020–2022, Okinawa prefecture, Japan

BackgroundWhile airport screening measures for COVID-19 infected passengers at international airports worldwide have been greatly relaxed, observational studies evaluating fever screening alone at airports remain scarce. The purpose of this study is to retrospectively assess the effectiveness of fever screening at airports in preventing the influx of COVID-19 infected persons.MethodsWe conducted a retrospective epidemiological analysis of fever screening implemented at 9 airports in Okinawa Prefecture from May 2020 to March 2022. The number of passengers covered during the same period was 9,003,616 arriving at 9 airports in Okinawa Prefecture and 5,712,983 departing passengers at Naha Airport. The capture rate was defined as the proportion of reported COVID-19 cases who would have passed through airport screening to the number of suspected cases through fever screening at the airport, and this calculation used passengers arriving at Naha Airport and surveillance data collected by Okinawa Prefecture between May 2020 and March 2021.ResultsFrom May 2020 to March 2021, 4.09 million people were reported to pass through airports in Okinawa. During the same period, at least 122 people with COVID-19 infection arrived at the airports in Okinawa, but only a 10 suspected cases were detected; therefore, the capture rate is estimated to be up to 8.2% (95% CI: 4.00-14.56%). Our result of a fever screening rate is 0.0002% (95%CI: 0.0003–0.0006%) (10 suspected cases /2,971,198 arriving passengers). The refusal rate of passengers detected by thermography who did not respond to temperature measurements was 0.70% (95% CI: 0.19–1.78%) (4 passengers/572 passengers).ConclusionsThis study revealed that airport screening based on thermography alone missed over 90% of COVID-19 infected cases, indicating that thermography screening may be ineffective as a border control measure. The fact that only 10 febrile cases were detected after screening approximately 3 million passengers suggests the need to introduce measures targeting asymptomatic infections, especially with long incubation periods. Therefore, other countermeasures, e.g. preboarding RT-PCR testing, are highly recommended during an epidemic satisfying World Health Organization (WHO) Public Health Emergency of International Concern (PHEIC) criteria with pathogen characteristics similar or exceeding SARS-CoV-2, especially when traveling to rural cities with limited medical resources.

Cost effectiveness and decision analysis for national airport screening options to reduce risk of COVID-19 introduction in Uganda, 2020

IntroductionEarly during the COVID-19 outbreak, various approaches were utilized to prevent COVID-19 introductions from incoming airport travellers. However, the costs and effectiveness of airport-specific interventions have not been evaluated.MethodsWe evaluated policy options for COVID-19-specific interventions at Entebbe International Airport for costs and impact on COVID-19 case counts, we took the government payer perspective. Policy options included; (1)no screening, testing, or mandatory quarantine for any incoming traveller; (2)mandatory symptom screening for all incoming travellers with RT-PCR testing only for the symptomatic and isolation of positives; and (3)mandatory 14-day quarantine and one-time testing for all, with 10-day isolation of persons testing positive. We calculated incremental cost-effectiveness ratios (ICERs) in US$ per additional case averted.ResultsExpected costs per incoming traveller were $0 (Option 1), $19 (Option 2), and $766 (Option 3). ICERs per case averted were $257 for Option 2 (which averted 4,948 cases), and $10,139 for Option 3 (which averted 5,097 cases) compared with Option I. Two-week costs were $0 for Option 1, $1,271,431 Option 2, and $51,684,999 Option 3. The per-case ICER decreased with increase in prevalence. The cost-effectiveness of our interventions was modestly sensitive to the prevalence of COVID-19, diagnostic test sensitivity, and testing costs.ConclusionScreening all incoming travellers, testing symptomatic persons, and isolating positives (Option 2) was the most cost-effective option. A higher COVID-19 prevalence among incoming travellers increased cost-effectiveness of airport-specific interventions. This model could be used to evaluate prevention options at the airport for COVID-19 and other infectious diseases with similar requirements for control.

Reconstructing the COVID-19 incidence in India using airport screening data in Japan.

A major epidemic of COVID-19 caused by the Delta variant (B.1.617.2) occurred in India from March to July 2021, resulting in 19 million documented cases. Given the limited healthcare and testing capacities, the actual number of infections is likely to have been greater than reported, and several modelling studies and excess mortality research indicate that this epidemic involved substantial morbidity and mortality. To estimate the incidence during this epidemic, we used border entry screening data in Japan to estimate the daily incidence and cumulative incidence of COVID-19 infection in India. Analysing the results of mandatory testing among non-Japanese passengers entering Japan from India, we calculated the prevalence and then backcalculated the incidence in India from February 28 to July 3, 2021. The estimated number of infections ranged from 448 to 576 million people, indicating that 31.8% (95% confidence interval (CI): 26.1, 37.7) - 40.9% (95% CI: 33.5, 48.4) of the population in India had experienced COVID-19 infection from February 28 to July 3, 2021. In addition to obtaining cumulative incidence that was consistent with published estimates, we showed that the actual incidence of COVID-19 infection during the 2021 epidemic in India was approximately 30 times greater than that based on documented cases, giving a crude infection fatality risk of 0.47%. Adjusting for test-negative certificate before departure, the quality control of which was partly questionable, the cumulative incidence can potentially be up to 2.3-2.6 times greater than abovementioned estimates. Our estimate of approximately 32-41% cumulative infection risk from February 28 to July 3, 2021 is roughly consistent with other published estimates, and they can potentially be greater, given an exit screening before departure. The present study results suggest the potential utility of border entry screening data to backcalculate the incidence in countries with limited surveillance capacity owing to a major surge in infections.

Efficient Thorax Disease Classification and Localization Using DCNN and Chest X-ray Images.

Thorax disease is a life-threatening disease caused by bacterial infections that occur in the lungs. It could be deadly if not treated at the right time, so early diagnosis of thoracic diseases is vital. The suggested study can assist radiologists in more swiftly diagnosing thorax disorders and in the rapid airport screening of patients with a thorax disease, such as pneumonia. This paper focuses on automatically detecting and localizing thorax disease using chest X-ray images. It provides accurate detection and localization using DenseNet-121 which is foundation of our proposed framework, called Z-Net. The proposed framework utilizes the weighted cross-entropy loss function (W-CEL) that manages class imbalance issue in the ChestX-ray14 dataset, which helped in achieving the highest performance as compared to the previous models. The 112,120 images contained in the ChestX-ray14 dataset (60,412 images are normal, and the rest contain thorax diseases) were preprocessed and then trained for classification and localization. This work uses computer-aided diagnosis (CAD) system that supports development of highly accurate and precise computer-aided systems. We aim to develop a CAD system using a deep learning approach. Our quantitative results show high AUC scores in comparison with the latest research works. The proposed approach achieved the highest mean AUC score of 85.8%. This is the highest accuracy documented in the literature for any related model.

Intelligent Eye-Tracker-Based Methods for Detection of Deception: A Survey

Over the last few years, a large number of studies have been conducted on the monitoring of human behavior remaining beyond conscious control. One area of application for such monitoring systems is lie detection. The most popular method currently used for this purpose is polygraph examination, which has proven its usefulness in the field and in laboratories, but it is not without its drawbacks. Technological advances in data acquisition and automated analysis have ensured that contactless tools are in high demand in security fields like airport screening or pre-employment procedures. As a result, there has been a shift in interest away from traditional polygraph examinations toward the analysis of facial expressions, voice, and speech patterns, as well as eye-tracking signals to detect deceptive behavior. In this paper, we focus on the last aspect, offer a comprehensive overview of two distinct lie detection methodologies based on eye tracking, and examine the commonly used oculomotor feature analysis. Furthermore, we explore current research directions and their results within the context of their potential applications in the field of forensics. We also highlight future research prospects, suggesting the utilization of eye tracking and scan path interpretation methodologies as a potential fully functional alternative for the conventional polygraph in the future. These considerations refer to legal and ethical issues related to the use of new technology to detect lies.

The impact of modern airport security protocols on patients with total shoulder replacements.

Advancements in airport screening measures in response to 9/11 have resulted in increased false alarm rates for patients with orthopedic and metal implants. With the implementation of millimeter-wave scanning technology, it is important to assess the changes in airport screening experiences of patients who underwent total shoulder arthroplasty (TSA). Here, 197 patients with prior anatomic and reverse TSA completed between 2013 and 2020 responded to a questionnaire regarding their experiences with airport travel screening after their operation. Of these patients, 86 (44%) stated that they had traveled by plane, while 111 (56%) had not. The questionnaire addressed several measures including the number of domestic and international flights following the operation, number of false alarm screenings by the millimeter-wave scanner, patient body habitus, and presence of additional metal implants. A total of 53 patients (62%) responded "yes" to false screening alarms due to shoulder arthroplasty. The odds of a false screening alarm for patients with other metal implants was 5.87 times that of a false screening alarm for patients with no other metal implants (P<0.1). Of a reported 662 flights, 303 (45.8%) resulted in false screening alarms. Greater body mass index was not significantly lower in patients who experienced false screening alarms (P=0.30). Patients with anatomic and reverse TSA trigger false alarms with millimeter-wave scanners during airport screening at rates consistent with prior reports following 9/11. Patient education on the possibility of false alarms during airport screening is important until improvements in implant identification are made. Level of evidence: IV.

Vaccination Approach Toward Monkeypox: An Urgent Call

Vaccination Approach Toward Monkeypox: An Urgent Call

Barriers and facilitators to COVID-19 screening at Jaipur International Airport, India.

Airports pose a possible threat in facilitating global disease transmission within the community which may be prevented by rigorous systematic entry-exit screening. This study captures the perception of stakeholders on barriers and facilitators of coronavirus disease 2019 (COVID-19) screening. Further, key outcomes viz. total passengers screened, suspected cases, and confirmed cases were assessed. An inductive-deductive mix-method thematic analysis was conducted to capture qualitative data of key stakeholders on COVID-19 disease screening at Jaipur International Airport. Additionally, secondary data retrieved from Rajasthan Medical & Health Department team deployed for COVID-19 airport screening were analyzed. Jaipur International Airport screened 4565 passengers (Males = 4073 and Females = 492) with 23 suspected cases during an outlined period of declaration of Pandemic to Lockdown in India (11 to 24 March 2020). Total 65 passengers had travel history from China (3 from Wuhan). The mean average age of passengers was 40.95 ± 7.8 years. The average screening time per passenger was 2-3 min with a load of 25-90 passengers per team per flight. Fishbone analysis of screening challenges revealed poor cooperation of passengers, masking symptoms, apprehension, and stigma related to quarantine. Moreover, inadequate human resources and changing guidelines overburdened healthcare providers. But, perception of risk, and social responsibility of travelers together with supportive organization behavior act as facilitators. Overall, groundwork on airport screening was insightful to propose key action areas for screening. Globally, COVID-19 has an impact on health infrastructure and international travel. International coordination with streamlined screening will go an extended way in virus containment.

Strategies for South Pacific Region to address future pandemics: Implications for the aviation and tourism sectors based on a systematic literature review (2010–2021)

This study systematically reviewed the literature on travel-related measures and policies for controlling and mitigating the adverse impacts of pandemics, with a focus on the air transport and tourism sectors. The key findings are applied to the South Pacific Region (SPR) so that appropriate business strategies and industrial policies can be developed to safeguard the sustained development of aviation and tourism. In total, 159 publications were selected and examined using descriptive analysis, content and thematic analyses and a meta-analysis. Our findings suggest that short-term policies and measures (e.g., border closures and travel restrictions, quarantine and isolation, hygiene measures, virus testing, contact tracing, airport screening and other measures) and a long-term strategy (vaccination) should both be implemented to address future pandemics in the SPR. A risk-based approach is recommended, which calls for effective coordination and collaboration across different governments in the region. In addition, the SPR governments should provide financial support for the recovery of the air transport and tourism sectors, both of which are the pillar industries of the SPR.

COVID-19 in Japan, January–March 2020: insights from the first three months of the epidemic

BackgroundUnderstanding the characteristics and natural history of novel pathogens is crucial to inform successful control measures. Japan was one of the first affected countries in the COVID-19 pandemic reporting their first case on 14 January 2020. Interventions including airport screening, contact tracing, and cluster investigations were quickly implemented. Here we present insights from the first 3 months of the epidemic in Japan based on detailed case data.MethodsWe conducted descriptive analyses based on information systematically extracted from individual case reports from 13 January to 31 March 2020 including patient demographics, date of report and symptom onset, symptom progression, travel history, and contact type. We analysed symptom progression and estimated the time-varying reproduction number, Rt, correcting for epidemic growth using an established Bayesian framework. Key delays and the age-specific probability of transmission were estimated using data on exposures and transmission pairs.ResultsThe corrected fitted mean onset-to-reporting delay after the peak was 4 days (standard deviation: ± 2 days). Early transmission was driven primarily by returning travellers with Rt peaking at 2.4 (95% CrI: 1.6, 3.3) nationally. In the final week of the trusted period (16–23 March 2020), Rt accounting for importations diverged from overall Rt at 1.1 (95% CrI: 1.0, 1.2) compared to 1.5 (95% CrI: 1.3, 1.6), respectively. Household (39.0%) and workplace (11.6%) exposures were the most frequently reported potential source of infection. The estimated probability of transmission was assortative by age with individuals more likely to infect, and be infected by, contacts in a similar age group to them. Across all age groups, cases most frequently onset with cough, fever, and fatigue. There were no reported cases of patients < 20 years old developing pneumonia or severe respiratory symptoms.ConclusionsInformation collected in the early phases of an outbreak are important in characterising any novel pathogen. The availability of timely and detailed data and appropriate analyses is critical to estimate and understand a pathogen’s transmissibility, high-risk settings for transmission, and key symptoms. These insights can help to inform urgent response strategies.

Positive security screening episodes of patients with spinal implants are influenced by detector type and not implant material

Previous research on rates of spinal detection showed a low frequency of patients (5%) experienced delays and additional screening going through airport security. With continuous technology advances in screenings and the rise in cobalt chrome implantation, updated data on patient experiences was needed. 1) Assess the rates of detection and additional screening by traditional metal detectors and full body scanners in patients with metal spinal implants, 2) Compare the rates of detection of various metal types (Titanium and cobalt-chrome, titanium only, and stainless steel) STUDY DESIGN: Retrospective PATIENT SAMPLE: All spine surgical follow-ups over survey period. Self-reported open questionnaire; frequency of airport screening, patients' feelings and attitudes towards screening. Patients were surveyed in the outpatient setting on exposure to metal detectors (Traditional and full-body scanners) after spinal surgery with metallic implants at a single institution. A total of 182 patients were identified and consented. The medical records were reviewed for details on implant material and location. Mean age at surgery was 53 years (range=12-88) with a mean 5.9 levels fused (range 2-20). Mean time from surgery to survey was 34 months (range=2-351) and number of airport screenings was 5.8 (range=0-54). The most common implants were titanium/cobalt-chrome (Ti/CoCr) (n=96, 53%) and titanium only (n=72, 40%). Overall, 40% of patients reported a detector alert at an airport requiring processing delay and additional screening: 86% from full body scanners, 54% from traditional metal detectors, and 41% of patients reporting both. Full body scanners were more likely to detect implants compared to traditional metal detectors (OR 5.1, p<.0001). No significant difference in number of screenings between patients who set off detectors and patients who did not (p=.185). Twenty percent of patients reported trouble at non-airport locations with detectors due to their spinal implants, with 70% of these patients reporting additional manual screenings. There was no correlation between levels spanned by the construct and number of times detected by traditional metal detectors or full body scanners, and no significant difference between levels spanned by constructs, or construct locations, in patients who set off detectors and those who did not. There was no significant difference between Ti/CoCr vs. titanium or other constructs in positive screenings. Subanalysis of fusions <5 levels demonstrated Ti/CoCr implants did not have an impact on positive screenings vs. other metal types (OR 0.88, p=.756). Interestingly, there was a significant difference in age and the positive screenings (p=.0025). Patients 60+ years of age had statistically significant greater positive screening than patients 0 to 40 years and 41 to 60 years. This data raises the possibility the presence of total joint arthroplasties (Mean age of patients with arthroplasty 65.5 years, range 50-88) likely play a significant role in the frequency of positive screenings. 40% of patients had their spinal implants detected at airports and 20% reported detections at other non-airport locations. Full body scanners detect spinal implants more frequently compared to traditional metal detectors (86% vs. 54% of detections, respectively). There was no difference in rate of airport and non-airport detection in patients with cobalt chrome implants compared to other materials. The presence of total joint arthroplasties likely has a significant contribution to the detector alerts.

Modeling the effects of preventive measures and vaccination on the COVID-19 spread in Benin Republic with optimal control

Coronavirus disease (COVID-19) onset in December 2019 is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since, the spread of the virus and mortality due to COVID-19 have continued to increase daily leading to a pandemic. In absence of approved medicine and vaccines, many countries imposed policies such as social distancing, mask wearing, hand washing, airport screening, quarantine and others. But rapidly, they were confronted with the high economic and social cost resulting from those policies. Many vaccines have been proposed but their efficiency is still controversial. Now, governments and scholars search for how manage with preventives measures policies and vaccination campaigns to stop the COVID-19 spread. This work studied the effects of these different strategies as time-dependent interventions using mathematical modeling and optimal control approach to ascertain their contribution in the dynamic transmission of COVID-19. The model was proven to have an invariant region and was well-posed. The basic reproduction number was computed with and without respect of preventives measures. The optimal control analysis was carried out using the Pontryagin’s maximum principle to figure out the optimal strategy necessary to curtail the disease. The findings revealed that the optimal implementation of preventive measures reduce highly the number of infected individuals but zero infection was not achieved in the population. That was obtained with the optimal implementation of vaccination campaigns which reduce the number of infected individuals. But the optimal and combined implementation of the two interventions performed better with less costs than the two singular implementations.

Epidemiological Characteristics of Infectious Diseases Among Travelers Between China and Foreign Countries Before and During the Early Stage of the COVID-19 Pandemic.

Background: International travel during the Coronavirus disease 2019 (COVID-19) pandemic carries a certain magnitude of infection risk both to travelers and their destination, which may be difficult to assess in the early stage. The characteristics of common infectious diseases of tourists may provide some clues to identify the high-risk travelers and protect susceptible population.Methods: From among 48,444 travelers screened at Shanghai Port, we analyzed 577 travelers with 590 infectious diseases for age, sex, disease type, and World Health Organization (WHO) regions. We used the Joinpoint Regression Program to identify the average percent changes (APC) in the various trends among these individuals.Results: Hepatitis B, syphilis, and HIV were the most common infectious diseases in travelers entering China, and Hepatitis B, pulmonary tuberculosis, and syphilis in Chinese nationals traveling abroad (overall detection rates, 1.43 and 0.74%, respectively; P < 0.05). Africa (2.96%), the Americas (1.68%), and the Western Pacific (1.62%) exhibited the highest detection rates. This trend did not decrease since the COVID-19 pandemic (P > 0.05) and rather showed an upward trend with increasing age [APC 95% CI = 5.46 (3.41,7.56)%, P < 0.05]. However, there were no evident trends in monthly infection rates of travelers exiting and entering China from different WHO regions (all P > 0.05).Conclusion: Travelers always carry a transmission risk of common infectious diseases. It may be reasonable to adjust strategies for airport screening and quarantine according to the age and departure area of travelers to prevent and control new infectious diseases.

Simulation Model of Airport Security Lanes with Power Consumption Estimation

The purpose of this paper was to develop a simulation model that allows simultaneous analysis of airport screening lane performance and power consumption per passenger served. These two issues have not yet been considered simultaneously in the scientific literature. So far, the focus has been placed on process performance. However, this paper shows, by performing an empirical study and applying the proposed model, that it is important to consider these two issues simultaneously. This will allow for the sustainable development of air transport. As a case study, three system configurations for single, dual and single fast screening lanes were analyzed. For each configuration, 3 different types of X-ray devices were checked, and the results were compared. The results showed that for example calculations with 2 million passengers handled per year, the gains could be as high as 4614 kWh/year. This article therefore shows that it is important to manage the process with power consumption in mind.

Barriers and Facilitators to COVID-19 screening at Jaipur International Airport, India.

Airports pose a possible threat in facilitating global disease transmission within the community which may be prevented by rigorous systematic entry-exit screening. Rajasthan Government has taken precautionary action at Jaipur International airport by screening passengers. The present article describes the entry-exit screening along with stakeholder perception on the barriers and facilitators associated with the screening. Secondary data was obtained from the Rajasthan Medical & Health Department team to categorize passengers for risk of COVID-19. A mix-method inductive-deductive thematic analysis was conducted. A total of 4565 passengers (Males=4073 and Females=492) with 23 suspected cases were screened during an outlined period of declaration of Pandemic to Lockdown in India (11 th to 24 th March 2020). The mean age of passengers was 40.95 ± 7.8 years. The average screening time per passenger was 2-3 minutes with a load of 25-90 passengers per team per flight. Fishbone analysis of screening revealed barriers like poor cooperation of passengers, masking symptoms, apprehension, and stigma related to quarantine. Inadequate human resources and changing guidelines overburdened healthcare providers. Perception of risk, and social responsibility of travelers together with supportive organization behavior act as facilitators. Overall, groundwork on airport screening was insightful to propose key action areas for streamlined screening in limiting transmission.

Non-contact breathing monitoring by integrating RGB and thermal imaging via RGB-thermal image registration

Altered breathing rate is an important sign of disease status. Currently used machine-based monitoring of the breathing rate includes contact with the body, which may result in pain and discomfort. In this paper, a non-contact breathing monitoring technique is proposed by integrating RGB and thermal imaging systems with RGB-thermal image registration. This method provides a linear mapping for automated selection of the region of interest (ROI) followed by tracking to extract the breathing rate. To evaluate the efficacy of the proposed approach and its robustness against motion, talking, varying breathing rate or rhythm, and high ambient temperature, this study was conducted in three phases. Validation of the proposed approach demonstrated a strong agreement with the reference method of breathing rate monitoring using a respiration belt. During normal breathing, the mean absolute error (MAE) reached 0.11 bpm (breaths per minute). While in more challenging conditions, defined by three phases, the MAE reached 1.46, 2.08, and 1.69 bpm, respectively. In short, the proposed method performance is a promising alternative to a contact-based method due to its strong agreement and might be useful in diverse applications such as sport studies, rehabilitation centres, quarantine centres, and in hospital or airport screening during the COVID 19 pandemic.

Risk Assessment of Importation and Local Transmission of COVID-19 in South Korea: Statistical Modeling Approach.

BackgroundDespite recent achievements in vaccines, antiviral drugs, and medical infrastructure, the emergence of COVID-19 has posed a serious threat to humans worldwide. Most countries are well connected on a global scale, making it nearly impossible to implement perfect and prompt mitigation strategies for infectious disease outbreaks. In particular, due to the explosive growth of international travel, the complex network of human mobility enabled the rapid spread of COVID-19 globally.ObjectiveSouth Korea was one of the earliest countries to be affected by COVID-19. In the absence of vaccines and treatments, South Korea has implemented and maintained stringent interventions, such as large-scale epidemiological investigations, rapid diagnosis, social distancing, and prompt clinical classification of severely ill patients with appropriate medical measures. In particular, South Korea has implemented effective airport screenings and quarantine measures. In this study, we aimed to assess the country-specific importation risk of COVID-19 and investigate its impact on the local transmission of COVID-19.MethodsThe country-specific importation risk of COVID-19 in South Korea was assessed. We investigated the relationships between country-specific imported cases, passenger numbers, and the severity of country-specific COVID-19 prevalence from January to October 2020. We assessed the country-specific risk by incorporating country-specific information. A renewal mathematical model was employed, considering both imported and local cases of COVID-19 in South Korea. Furthermore, we estimated the basic and effective reproduction numbers.ResultsThe risk of importation from China was highest between January and February 2020, while that from North America (the United States and Canada) was high from April to October 2020. The R0 was estimated at 1.87 (95% CI 1.47-2.34), using the rate of α=0.07 for secondary transmission caused by imported cases. The Rt was estimated in South Korea and in both Seoul and Gyeonggi.ConclusionsA statistical model accounting for imported and locally transmitted cases was employed to estimate R0 and Rt. Our results indicated that the prompt implementation of airport screening measures (contact tracing with case isolation and quarantine) successfully reduced local transmission caused by imported cases despite passengers arriving from high-risk countries throughout the year. Moreover, various mitigation interventions, including social distancing and travel restrictions within South Korea, have been effectively implemented to reduce the spread of local cases in South Korea.

First Identified Cases of SARS-CoV-2 Variant P.1 in the United States - Minnesota, January 2021.

Since December 2020, the Minnesota Department of Health (MDH) Public Health Laboratory has been receiving 100 specimens per week (50 from each of two clinical partners) with low cycle threshold (Ct) values for routine surveillance for SARS-CoV-2, the virus that causes COVID-19. On January 25, 2021, MDH identified the SARS-CoV-2 variant P.1 in one specimen through this surveillance system using whole genome sequencing, representing the first identified case of this variant in the United States. The P.1 variant was first identified in travelers from Brazil during routine airport screening in Tokyo, Japan, in early January 2021 (1). This variant has been associated with increased transmissibility (2), and there are concerns that mutations in the spike protein receptor-binding domain might disrupt both vaccine-induced and natural immunity (3,4). As of February 28, 2021, a total of 10 P.1 cases had been identified in the United States, including the two cases described in this report, followed by one case each in Alaska, Florida, Maryland, and Oklahoma (5).

Definitions for coronavirus disease 2019 reinfection, relapse and PCR re-positivity

Definitions for coronavirus disease 2019 reinfection, relapse and PCR re-positivity