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Objective: To examine the impact of COVID-19 pandemic on the epidemic status of imported malaria and national malaria control program in China, so as to provide insights into post-elimination malaria surveillance., Methods: All data pertaining to imported malaria cases were collected from Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 through December 31, 2021. The number of malaria cases, species of malaria parasites, country where malaria parasite were infected, diagnosis and treatment after returning to China, and response were compared before (from January 1, 2018 to January 22, 2020) and after the COVID-19 pandemic (from January 23, 2020 to December 31, 2021)., Results: A total of 2 054 imported malaria cases were reported in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region during the period from January 1, 2018 to December 31, 2021, and there were 1 722 cases and 332 cases reported before and after the COVID-19 pandemic, respectively. All cases were reported within one day after definitive diagnosis. The annual mean number of reported malaria cases reduced by 79.30% in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region after the COVID-19 pandemic (171 cases) than before the pandemic (826 cases), and the number of monthly reported malaria cases significantly reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region since February 2020. There was a significant difference in the constituent ratio of species of malaria parasites among the imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic ( χ 2 = 146.70, P malaria was predominant before the COVID-19 pandemic (72.30%), while P. falciparum malaria (44.28%) was predominant after the COVID-19 pandemic, followed by P. ovale malaria (37.65%). There was a significant difference in the constituent ratio of country where malaria parasites were infected among imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic ( P. falciparum malaria (37.65%). There was a significant difference in the constituent ratio of country where malaria parasites were infected among imported malaria cases in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region before and after the COVID-19 pandemic ( χ 2 infections in western Africa reduced after the COVID-19 pandemic that before the pandemic (44.13% vs. 37.95%; P < 0.05), and the proportion of malaria cases that acquired Plasmodium infections in western Africa reduced after the COVID-19 pandemic that before the pandemic (44.13% vs. 37.95%; χ infections in eastern Africa increased after the COVID-19 pandemic that before the pandemic (9.58% vs. 15.36%; 2 = 4.34, P = 0.02). The proportion of completing case investigation within 3 days was significantly lower after the COVID-19 pandemic than before the pandemic (96.69% vs. 98.32%; Plasmodium infections in eastern Africa increased after the COVID-19 pandemic that before the pandemic (9.58% vs. 15.36%; χ < 0.05), while the proportion of finishing foci investigation and response within 7 days was significantly higher after the COVID-19 pandemic than before the pandemic (100.00% vs. 98.43%; 2 = 9.88, P = 0.02). The proportion of completing case investigation within 3 days was significantly lower after the COVID-19 pandemic than before the pandemic (96.69% vs. 98.32%; χ 2 = 3.87, P < 0.05), while the proportion of finishing foci investigation and response within 7 days was significantly higher after the COVID-19 pandemic than before the pandemic (100.00% vs. 98.43%; χ 2 = 3.95, P < 0.05)., Conclusions: The number of imported malaria cases remarkably reduced in Anhui Province, Hubei Province, Henan Province, Zhejiang Province and Guangxi Zhuang Autonomous Region of China during the COVID-19 pandemic, with a decreased proportion of completing case investigations within 3 days. The sensitivity of the malaria surveillance-response system requires to be improved to prevent the risk of secondary transmission of malaria due to the sharp increase in the number of imported malaria cases following the change of the COVID-19 containment policy.

This article presents a severe cerebral malaria patient in shock with a close contact of COVID-19 that was successfully cured in a negative pressure ward during the global pandemic of COVID-19. The patient experienced a sudden onset of high fever and coma in a designated isolation hotel after returning from Africa, and was transferred to a designated hospital. Following antimalarial therapy, blood pressure elevation, increase of blood volume, bedside hemodialysis, mechanical ventilation, plasma and platelet transfusions, the case gradual recovered.

Background: Global transmission from imported cases to domestic cluster infections is often the origin of local community-acquired outbreaks when facing emerging SARS-CoV-2 variants., Objective: We aimed to develop new surveillance metrics for alerting emerging community-acquired outbreaks arising from new strains by monitoring the risk of small domestic cluster infections originating from few imported cases of emerging variants., Methods: We used Taiwanese COVID-19 weekly data on imported cases, domestic cluster infections, and community-acquired outbreaks. The study period included the D614G strain in February 2020, the Alpha and Delta variants of concern (VOCs) in 2021, and the Omicron BA.1 and BA.2 VOCs in April 2022. The number of cases arising from domestic cluster infection caused by imported cases (Dci/Imc) per week was used as the SARS-CoV-2 strain-dependent surveillance metric for alerting local community-acquired outbreaks. Its upper 95% credible interval was used as the alert threshold for guiding the rapid preparedness of containment measures, including nonpharmaceutical interventions (NPIs), testing, and vaccination. The 2 metrics were estimated by using the Bayesian Monte Carlo Markov Chain method underpinning the directed acyclic graphic diagram constructed by the extra-Poisson (random-effect) regression model. The proposed model was also used to assess the most likely week lag of imported cases prior to the current week of domestic cluster infections., Results: A 1-week lag of imported cases prior to the current week of domestic cluster infections was considered optimal. Both metrics of Dci/Imc and the alert threshold varied with SARS-CoV-2 variants and available containment measures. The estimates were 9.54% and 12.59%, respectively, for D614G and increased to 14.14% and 25.10%, respectively, for the Alpha VOC when only NPIs and testing were available. The corresponding figures were 10.01% and 13.32% for the Delta VOC, but reduced to 4.29% and 5.19% for the Omicron VOC when NPIs, testing, and vaccination were available. The rapid preparedness of containment measures guided by the estimated metrics accounted for the lack of community-acquired outbreaks during the D614G period, the early Alpha VOC period, the Delta VOC period, and the Omicron VOC period between BA.1 and BA.2. In contrast, community-acquired outbreaks of the Alpha VOC in mid-May 2021, Omicron BA.1 VOC in January 2022, and Omicron BA.2 VOC from April 2022 onwards, were indicative of the failure to prepare containment measures guided by the alert threshold., Conclusions: We developed new surveillance metrics for estimating the risk of domestic cluster infections with increasing imported cases and its alert threshold for community-acquired infections varying with emerging SARS-CoV-2 strains and the availability of containment measures. The use of new surveillance metrics is important in the rapid preparedness of containment measures for averting large-scale community-acquired outbreaks arising from emerging imported SARS-CoV-2 variants., (©Amy Ming-Fang Yen, Tony Hsiu-Hsi Chen, Wei-Jung Chang, Ting-Yu Lin, Grace Hsiao-Hsuan Jen, Chen-Yang Hsu, Sen-Te Wang, Huong Dang, Sam Li-Sheng Chen. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 25.11.2022.)

The importation of COVID-19 cases in China is due to the returning of Chinese citizens abroad, where the majority of cases stand. This study aimed to evaluate the risk of importing COVID-19 into the Sichuan Province of China and conduct a short-term risk prediction assessment and analysis. Data on COVID-19 cases in each country and Sichuan were collected, as well as visitors to Sichuan, population, area, and medical resources in each city in Sichuan province. According to different control strategies of entry aviation and quarantine control, we built models of epidemic transmission to estimate the risk for imported COVID-19 cases in 21 cities of Sichuan. Within 140 days of the policy change's implementation, the number of susceptible, infected, and recovered people in all cities followed the same pattern over time: (1) the number of susceptible people declined slowly at first, then accelerated to reach a stable value; (2) the number of infections gradually increased to a peak, then decreased; and (3) the number of recovered patients gradually increased to a stable value. Under the four different scenarios, there were no significant differences between the risk peaks because the social distance did not change. However, the peak time would be delayed due to the implementation of flight control and nucleic acid detection measures. The improvement of foreign epidemics (reduction of attenuation factors) all delayed the arrival of the peak risk value in Chengdu by about 20 days; however, the size of the peak value did not change significantly. The improvement of nucleic acid detection accuracy delayed the arrival of the peak risk value in Chengdu, but the size of the peak value did not change significantly. Therefore, flight control and the improvement of nucleic acid detection accuracy and overseas epidemic situations have positively affected the prevention and control of the epidemic in Sichuan., (© 2022 Wiley-VCH GmbH.)

Background: The goal of this study was to understand the epidemiological characteristics of imported malaria in Shanghai specifically during the epidemic period of novel corona-virus pneumonia (COVID-19), to provide a reference for preventing the transmission of imported malaria after this disease had been previously eliminated., Methods: The data of malaria cases reported in Shanghai from 2020 to 2021 were obtained from the China Information System for Disease Control and Prevention (CISDCP) and the Information System for Parasitic Disease Control and Prevention (ISPDCP). The characteristics of demographic and epidemiological distribution, travel-related information, diagnosis information, regions of infection acquisition and disposal information of epidemic situation were analysed with descriptive statistics., Results: A total of 112 cases of malaria were reported in Shanghai from January 2020 to December 2021. There were 18 cases and 94 cases in 2020 and 2021, respectively, reaching the lowest and highest levels in the past 10 years. The incidence of malaria associated with seasons had an increasing trend (χ 2  = 81.143, P < 0.05). These cases included Plasmodium falciparum (97, 86.61%), Plasmodium vivax (4, 3.57%), Plasmodium ovale (8, 7.14%) and Plasmodium malariae (3, 2.68%). The median age of patients with malaria was 38.0 years, the majority of these individuals were males (109, 97.32%), and most of them were labour personnel (93, 83.04%). Of the reported cases, 8 of these individuals (7.14%) reported experiencing malaria symptoms before their arrival in China after their stay overseas; 97 of these individuals (86.61%) reported experiencing symptoms within 14 days after their initial arrival from overseas; 15 of these individuals (13.39%) were diagnosed with 'severe malaria'; and 4 of these individuals (3.57%) were also diagnosed with COVID-19. All cases were imported from Africa, and there were no indigenous cases and deaths., Conclusion: Due to the impact of COVID-19, the number of imported malaria cases in Shanghai had greatly increased; however, prevention and control measures for imported malaria could be implemented to prevent re-transmission of this condition. Considering that the number of individuals returning from overseas labour is likely to increase in the next few years, it is necessary to strengthen the surveillance of imported malaria and to review the protocol for potential epidemic situations. Together, these measures could support the maintation of free-malaria status in Shanghai., (© 2022. The Author(s).)

Objectives: With the continuous generation of new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pressure of epidemic prevention and control continues to increase in China. Omicron with stronger infectiousness, immune escape ability and repeated infection ability spread to many countries and regions around the world in a short period of time. China has also successively reported cases of imported Omicron infections. This study aims to understand the epidemiological characteristics of Omicron variant via analyzing the epidemiological characteristics of imported patients with Omicron in Hunan Province, and to provide reference for preventing and controlling the imported epidemics., Methods: The clinical data of imported patients with coronavirus disease 2019 admitted to Hunan Province from December 16 to December 31, 2021 were retrospectively collected. The epidemiological information, general information, clinical classification, clinical symptoms, vaccination status, and lung CT were analyzed. Nasopharyngeal swabs and blood samples were collected. Virus nucleic acid was detected by magnetic beads method using SARS-CoV-2 detection kit. Ct values of ORF1ab gene and N gene were compared between asymptomatic infected patients and confirmed patients. The specific IgM and IgG antibodies were detected by chemiluminescence assay using SARS-CoV-2 IgM test kit and SARS-CoV-2 IgG test kit, respectively. Ct values of IgM and IgG antibodies were compared between asymptomatic infected patients and confirmed patients., Results: Seventeen patients with Omicron variant infection were treated in Hunan, including 15 confirmed patients (5 common type and 10 mild type) and 2 asymptomatic infection patients. The 17 patients were all Chinese, they were generally young, and 16 were male. There were 9 patients with diseases. Of them 3 patients had respiratory diseases. All 17 patients had completed the whole process of vaccination, but only one person received a booster shot of SARS-CoV-2 vaccine. The clinical manifestations of the patients were mild, mainly including dry/painful/itchy throat, cough, and fatigue. The total protein and creatine in the asymptomatic infection and confirmed cases infected with Omicron variant were all within the normal range, but other biochemical indicators were abnormal. There were the significant differences in C-reactive protein and fibrinogen between asymptomatic infection and confirmed patients (both P <0.05). There were more patients with elevated C-reactive protein in confirmed patients than without confirmed ones. The detection rate of specific IgM and IgG antibodies on admission was 100%, and there was no significant difference in the specific antibody levels between asymptomatic infection and confirmed patients ( P >0.05). There were no significant differences in Ct values of ORF1ab gene and N gene (21.35 and 18.39 vs 19.22 and 15.67) between the asymptomatic infection and the confirmed patients (both P >0.05). Only 3 patients had abnormal lung CT, showing a small amount of patchy and cord-like shadows. One of them had no abnormality on admission but had pulmonary lesions and migratory phenomenon after admission., Conclusions: The patients with Omicron variant tend to be young people and have milder clinical symptoms, but the viral load is high and the infectiveness is strong. Therefore, the timely identification and effective isolation and control for asymptomatic infections and confirmed patients with mild symptoms are extremely important. In terms of epidemic prevention and control, the government still needs to strengthen the risk control of overseas input, adhere to normalized epidemic prevention and control measures, to effectively control the source of infection, cut off the route of transmission, and protect vulnerable people.

Background: The COVID-19 pandemic has elicited imposition of some form of travel restrictions by almost all countries in the world. Most restrictions currently persist, although some have been gradually eased. It remains unclear if the trade-off from the unprecedented disruption to air travel was well worth for pandemic containment., Method: A comparative analysis was conducted on Singapore, Taiwan, Hong Kong and South Korea's COVID-19 response. Data on COVID-19 cases, travel-related and community interventions, socio-economic profile were consolidated. Trends on imported and local cases were analyzed using computations of moving averages, rate of change, particularly in response to distinct waves of travel-related interventions due to the outbreak in China, South Korea, Iran & Italy, and Europe., Results: South Korea's travel restrictions were observed to be consistently more lagged in terms of timeliness and magnitude, with their first wave of travel restrictions on flights departing from China implemented 34 days after the outbreak in Wuhan, compared to 22-26 days taken by Singapore, Taiwan and Hong Kong. South Korea's restrictions against all countries came after 91 days, compared to 78-80 days for the other three countries. The rate of change of imported cases fell by 1.08-1.43 across all four countries following the first wave of travel restrictions on departures from China, and by 0.22-0.52 in all countries except South Korea in the fifth wave against all international travellers. Delayed rate of change of local cases resulting from travel restrictions imposed by the four countries with intrinsic importation risk, were not observed., Conclusions: Travel restriction was effective in preventing COVID-19 case importation in early outbreak phase, but may still be limited in preventing general local transmission. The impact of travel restrictions, regardless of promptness, in containing epidemics likely also depends on the effectiveness of local surveillance and non-pharmaceutical interventions concurrently implemented., (© 2021. The Author(s).)

Objective: To explore clustered epidemic of COVID-19 in Liaocheng city and analyze infection status and chain of transmission of the cases. Methods: A joint investigation team of emergency response for COVID-19 epidemic by CDC professional workers of Liaocheng city and district at two levels on January 30, 2020. According to a indicator case from ZH supermarkets, close contacts and related subjects were tracked and screened on February 1, including ZH supermarket employees, family members having contact history with related cases during January 13-26, supermarket clients during January 16-30 and family members of related cases. an epidemiological investigation was carried on and their swab of nose/throat were collected and were sent to Liaocheng CDC laboratory, real-time fluorescence quantitative RT-PCR was used to detect nucleic acids of SARS-CoV-2. Results: a total of 8 437 people were screened during January 30 to February 9, 2020 (120 employees of supermarket, 93 family members, and 8224 clients of supermarket). The epidemic was caused by ZH cases and brought clustered cases in four families. A total 25 cases of SARS-CoV-2 infection, the total infection rate of subjects was 0.30% (25/8 437) with 22 confirmed cases (0.26%, 22/8 437) and 3 asymptomatic patients (0.04%, 3/8 437), asymptomatic patients accounted for 12.00% (3/25) of all infection cases. The infection rates of supermarket employees, family members of confirmed cases and supermarket clients were 9.17% (11/120), 12.90% (12/93) and 0.02% (2/8 224). Conclusions: This was a cluster epidemic caused by one imported case of COVID-19 in a supermarket of Liaocheng city. Prevention and control of cluster epidemic should be focused on chain of community transmission and family cluster cases. It must also be an attention for transmission risk of asymptomatic patients.

Objective: To understand the epidemiological characteristics of imported COVID-19 cases in Guangzhou and provide scientific basis for the prevention and control of the disease. Methods: The data of imported COVID-19 in Guangzhou reported as of April 1, 2020 were collected from National Notifiable Disease Report System of China. The software Excel 2010 and SPSS 19.0 were applied for data cleaning and statistical analysis. Results: As of April 1, 2020, a total of 103 imported COVID-19 cases had been reported in Guangzhou, in which 92 were confirmed cases and 11 were asymptomatic infection cases. The number of the confirmed imported cases accounted for 11.4 % (92/806) in of the total in China at the same time. The male to female ratio of the cases was 1.58∶1 (63∶40). The median age of the cases was 31 years ( P(25) - P(75) :22-40 years), range of age was 11-63 years. The main occupational distributions of the cases were business services (41/103, 39.8 % ) and students (36/103, 35.0 % ). The imported cases whose destinations were 19 provinces and municipalities rather than Guangdong after entering the country accounted for 43.7 % . The main source countries of infections were the United Kingdom (27/103, 26.2 % ), the Philippines (13/103, 12.6 % ), the United States (13/103, 12.6 % ) and Nigeria (7/103, 6.8 % ). There were 34 inbound flights from which the imported COVID-19 cases were detected, in which 10 flights (10/34, 29.4 % ) were found to carry more than 3 cases, with an average voyage time of (11.14±0.53) hours. A total of 29 imported cases(28.2 % ) showed symptoms before entering the country, and 65 cases (63.1 % ) had been isolated before the onset of the disease. The mean free activity time of the isolated cases after the onset was (6.76±0.79) days. The average number of the imported cases' close contacts was 53. There were 13 clusters of COVID-19 caused by the imported cases, involving 36 cases (including 1 imported associated case). Conclusions: The sources of the imported COVID-19 cases in Guangzhou were widely distributed, and no cases had been found to be infected on the flights. In the early stage of the imported epidemic, there was high risk for the spread of the epidemic. Strengthened prevention and control of imported COVID-19 effectively reduced the of transmission risk of COVID-19 in communities.

BACKGROUND: Hong Kong enforced stringent travel restrictions during the COVID-19 pandemic. Understanding the characteristics of imported COVID-19 cases is important for establishing evidence-based control measures. METHODS: Retrospective cohort study summarising the characteristics of imported cases detected in Hong Kong between 13 November 2020 and 31 January 2022, when compulsory quarantine was implemented. FINDINGS: A total of 2269 imported COVID-19 cases aged 0-85 years were identified, of which 48.6 % detected on arrival. A shorter median delay from arrival to isolation was observed in Delta and Omicron cases (3 days) than in ancestral strain and other variants cases (12 days; p

Background: Hong Kong enforced stringent travel restrictions during the COVID-19 pandemic. Understanding the characteristics of imported COVID-19 cases is important for establishing evidence-based control measures. Methods: Retrospective cohort study summarising the characteristics of imported cases detected in Hong Kong between 13 November 2020 and 31 January 2022, when compulsory quarantine was implemented. Findings: A total of 2269 imported COVID-19 cases aged 0–85 years were identified, of which 48.6 % detected on arrival. A shorter median delay from arrival to isolation was observed in Delta and Omicron cases (3 days) than in ancestral strain and other variants cases (12 days; p

ObjectiveTo estimate the optimal quarantine period for inbound travelers and identify key risk factors to provide scientific reference for emerging infectious diseases.MethodsA parametric survival analysis model was used to calculate the time interval between entry and first positive nucleic acid test of imported cases in Guangzhou, to identify the influencing factors. And the COVID-19 epidemic risk prediction model based on multiple risk factors among inbound travelers was constructed.ResultsThe approximate 95th percentile of the time interval was 14 days. Multivariate analysis found that the mean time interval for inbound travelers in entry/exit high-risk occupations was 29% shorter (OR 0.29, 95% CI 0.18–0.46, p

The study aimed to determine the trends in the manifestations and severity over the epidemic course of imported COVID-19 cases, with comparison to native cases. The clinical characteristics of imported and native Chinese COVID-19 cases included in the study were assessed and compared. The association was analyzed using Mann-Whitney U test for categorical variables, Kruskal-Wallis H test for continuous variables, and Spearman's correlation test for disease severity. A total of 247 imported patients were enrolled, with an average age of 29 years, and 41.3% were female. The imported patients were younger than the native patients (29 vs 47 years) and included a lower proportion of fever (44.1%), chills (5.3%), fatigue (10.1%), leukopenia (14.6%), lymphopenia (39.3%), elevated C-reactive protein (CRP) (7.3%), elevated D-dimer (16.3%), and pneumonia (65.6%). Among patients with moderate severity, imported cases had a lower proportion of fever (44.2%), dyspnea (8.3%), and increased CRP (7.7%) than native cases. COVID-19 infection was less severe in imported cases than that in native cases.

Abstract Background The goal of this study was to understand the epidemiological characteristics of imported malaria in Shanghai specifically during the epidemic period of novel corona-virus pneumonia (COVID-19), to provide a reference for preventing the transmission of imported malaria after this disease had been previously eliminated. Methods The data of malaria cases reported in Shanghai from 2020 to 2021 were obtained from the China Information System for Disease Control and Prevention (CISDCP) and the Information System for Parasitic Disease Control and Prevention (ISPDCP). The characteristics of demographic and epidemiological distribution, travel-related information, diagnosis information, regions of infection acquisition and disposal information of epidemic situation were analysed with descriptive statistics. Results A total of 112 cases of malaria were reported in Shanghai from January 2020 to December 2021. There were 18 cases and 94 cases in 2020 and 2021, respectively, reaching the lowest and highest levels in the past 10 years. The incidence of malaria associated with seasons had an increasing trend (χ2 = 81.143, P

Objective To compare the clinical features of Omicron and Delta cases, so as to provide scientific basis for the prevention and treatment of COVID-19. Methods The case-control study method was used to retrospectively analyze the clinical data of the Omicron cases admitted to the designated hospital for the treatment of COVID-19 in Xi’an from December 2021 to January 2022. and the Delta cases admitted during the same period were used as the control group. The demographic data, epidemiological history, vaccination status, clinical characteristics, laboratory tests, nucleic acid and antibody levels, and outcomes of patients in the two groups were collected and compared. Results A total of 21 patients were included in the study, 5 were Omicron patients and 16 were Delta cases. The mean age of the patients in the two groups were（38.20±15.07） and（37.69±10.39） years, respectively. The time interval between the last vaccination and the diagnosis was（145.40±77.92） days and （159.00±99.74）days,respectively.For the initial symptoms, the patients with Omicron were mainly characterized by throat discomfort（3,60%）,cough and sputum（2,40%）,and the patients with Delta were mainly characterized by throat discomfort（5,31.25%）,fatigue（5,31.25%）,cough and sputum（4,25%）.On admission, laboratory tests showed that 60% of Omicron patients had low lymphocytes and elevated erythrocyte sedimentation rate,and50% of patients in the delta group had elevated hemoglobin. The Ct values of ORFlab gene, N gene and E gene with Omicron were lower than those with Delta. And the difference of E gene between the two groups was statistically significant （t=-2.711,P=0.024）.IgG antibody levels increased in both groups. The time for nucleic acid to turn negative with Omicron was（28.20±5.89）days,and it was（18.50±7.73）days with Delta, and the difference between the groups was statistically significant （t=2.565,P=0.019）.The length of hospitalization with Omicron was（30.60±4.88）days,and that with Delta was（22.13±7.81）days,and the difference was statistically significant （t=2.270,P=0.035）.Conclusions The initial symptoms of Omicron patients are mainly throat discomfort, cough and sputum. The clinical manifestations are generally mild. The nucleic acid test Ct value is lower. The time for nucleic acid to turn negative and the time for hospitalization are longer, and the potential infectiousness is stronger. Those eligible for vaccination should complete the full course of vaccination and booster vaccination as soon as possible. At the same time,the management of “early detection, early reporting, early isolation, and early treatment” should be implemented. [ABSTRACT FROM AUTHOR]

Abstract Background The COVID-19 pandemic has elicited imposition of some form of travel restrictions by almost all countries in the world. Most restrictions currently persist, although some have been gradually eased. It remains unclear if the trade-off from the unprecedented disruption to air travel was well worth for pandemic containment. Method A comparative analysis was conducted on Singapore, Taiwan, Hong Kong and South Korea’s COVID-19 response. Data on COVID-19 cases, travel-related and community interventions, socio-economic profile were consolidated. Trends on imported and local cases were analyzed using computations of moving averages, rate of change, particularly in response to distinct waves of travel-related interventions due to the outbreak in China, South Korea, Iran & Italy, and Europe. Results South Korea’s travel restrictions were observed to be consistently more lagged in terms of timeliness and magnitude, with their first wave of travel restrictions on flights departing from China implemented 34 days after the outbreak in Wuhan, compared to 22–26 days taken by Singapore, Taiwan and Hong Kong. South Korea’s restrictions against all countries came after 91 days, compared to 78–80 days for the other three countries. The rate of change of imported cases fell by 1.08–1.43 across all four countries following the first wave of travel restrictions on departures from China, and by 0.22–0.52 in all countries except South Korea in the fifth wave against all international travellers. Delayed rate of change of local cases resulting from travel restrictions imposed by the four countries with intrinsic importation risk, were not observed. Conclusions Travel restriction was effective in preventing COVID-19 case importation in early outbreak phase, but may still be limited in preventing general local transmission. The impact of travel restrictions, regardless of promptness, in containing epidemics likely also depends on the effectiveness of local surveillance and non-pharmaceutical interventions concurrently implemented.

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic continues to expand. Herein, we report the epidemiological and clinical features of 478 patients with confirmed COVID-19 from a multicenter study conducted in four cities in China excluding Wuhan. Methods A total of 478 patients transferred by emergency medical services to designated hospitals in four major cities in China (Beijing, Chongqing, Jinan, and Nanning) were enrolled. We compared the characteristics of imported and indigenous cases and calculated the frequencies of fatal, severe, mild, and asymptomatic disease. The results were used to generate a pyramid of COVID-19 severity. Results The mean age of patients with COVID-19 was 46.9 years and 49.8% were male. The most common symptoms at onset were fever (69.7%), cough (47.5%), fatigue (24.5%), dyspnea (8.4%), and headache (7.9%). Most cases (313, 65.5%) were indigenous, while 165 (34.5%) were imported. Imported cases dominated during the early stages of the pandemic, but decreased from 1 February 2020 as indigenous cases rose sharply. Compared with indigenous cases, imported cases differed significantly in terms of sex (P = 0.002), severity of disease (P = 0.006), occurrence of fever (P

Background: The coronavirus disease of 2019 (COVID-19) pandemic shocked the world, overwhelming the health systems of even high-income countries. Predictably, the situation has elicited social and medical responses from the public and governments, respectively. Nigeria recorded an imported case from Italy on February 27, 2020. Hence, this paper assesses the early socio-medical response to COVID-19 in Nigeria in the first 100 days after the index case. The paper employs analytical methods and collates data from various media reports and official sources. Findings: The incidence of COVID-19 grew steadily in Nigeria, moving from an imported case and elitist pattern to community transmission. The case fatality stood at 2.8%. The country recorded an upsurge (52% of total cases) in the transmission of COVID-19 during the short period the lockdown was relaxed. This paper presents a concise response framework to highlight some specific multisectoral responses to the pandemic. A combination of social and medical responses to a large extent helped Nigeria curtail the spread of the virus. Conclusion: The potential of overwhelming COVID-19 is still imminent in Nigeria as the country is attempting to hurriedly open the economy, which could sacrifice public health gains for temporary economic gains.

This study aimed to observe the initial trend of imported COVID-19 cases in South Korea since the beginning of the outbreak. All imported cases were classified into 5 regions (China, Asia, Europe, Africa, and America) according to travel history and potential exposure to the COVID-19. The list of countries for which confirmed cases had a travel history (single visit, multiple visits) and presented, were used to estimate the potential “exposure countries” of confirmed cases. For better understanding of the overall imported cases, time differences (day) among 3 major steps (symptom onset, entry to South Korea, laboratory confirmation) were measured based on available data. From the first importation of a COVID-19 case on January 20th, a total of 171 imported cases have been officially reported in South Korea as of March 23rd 2020. The overall trend of importation has significantly changed during this period. Importation of confirmed cases were initially from China, and subsequently from other Asian countries. After that, importation from Europe rapidly increased, with importation from America also increasing. One hundred fifteen (81%) were confirmed within 7 days of symptom onset. One Hundred forty three (84.1%) imported cases were confirmed within a week after entry into South Korea. One hundred seven imported cases (75.9%) developed symptoms within 5 days before or after, entry to South Korea. Streamlined processes of detection, subsequent testing, isolation, and treatment by public health authority, was key in minimizing the risk of secondary transmission.

Background There is a global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Information on viral genomics is crucial for understanding global dispersion and for providing insight into viral pathogenicity and transmission. Here, we characterized the SARS-CoV-2 genomes isolated from five travelers who returned to Taiwan from the United States of America (USA) between March and April 2020. Methods Haplotype network analysis was performed using genome-wide single-nucleotide variations to trace potential infection routes. To determine the genetic variations and evolutionary trajectory of the isolates, the genomes of isolates were compared to those of global virus strains from GISAID. Pharyngeal specimens were confirmed to be SARS-CoV-2-positive by RT-PCR. Direct whole-genome sequencing was performed, and viral assemblies were subsequently uploaded to GISAID. Comparative genome sequence and single-nucleotide variation analyses were performed. Results The D614G mutation was identified in imported cases, which separated into two clusters related to viruses originally detected in the USA. Our findings highlight the risk of spreading SARS-CoV-2 variants through air travel and the need for continued genomic tracing for the epidemiological investigation and surveillance of SARS-CoV-2 using viral genomic data. Conclusions Continuous genomic surveillance is warranted to trace virus circulation and evolution in different global settings during future outbreaks.

Background: Overseas imported cases of COVID-19 continue to increase in China, so we conducted this study to review the epidemiological characteristics of these patients.Methods: From February 26 to April 4, 2020, the imported cases from abroad were enrolled in this study. The effect of prevention countermeasures in curbing the spread of COVID-19 was assessed in this study. Moreover, we defined incubation period and confirmed time as from the date of leaving the epicenter to date of symptom onset and date of final diagnosed, respectively, and the interval of symptom onset to final diagnosed time was defined as diagnostic time. Categorical variables were summarized as numbers and percentages, and the difference among the variables were analyzed.Results: For 670 cases imported from abroad, 555 were Chinese and 115 were foreigners. Apparently, confirmed cases had significantly decreased after China was compelled to temporarily suspend the entry of foreign passport holders with valid visas or residence permits; 6 days after implement of controlled measures, the daily new confirmed cases were reduced to 13 cases. Moreover, about 84.3% of patients (166/197) presented symptoms 1 week after leaving the epicenter, and notably seven patients (3.6%) had symptoms 2 weeks after leaving the epicenter. The median incubation period was 3.0 days (inter quartile range, 1.0 to 6.0), the 95th percentile was 11.6 days. Additionally, most of cases (92.9%) were detected positively of nucleic acid after symptom onset with 4 days, the median diagnostic time was 2.0 days (interquartile range, 1.0 to 3.0), and the 95th percentile of the distribution was 5.0 days. Finally, about 5.8% of patients were healthy carriers, and the median confirmed time of asymptomatic patients was 4.0 days (interquartile range, 2.0 to 9.0). The following variables might be associated with confirmed time: symptom type (P = 0.005), exported regions (P < 0.001), and symptom onset time (P < 0.001).Conclusions: The prevention countermeasures for imported cases implemented by the Chinese government played an indispensable role in curbing the spread of COVID-19; the time of departure from epicenter could provide an estimate of the incubation period; and a confirmed time, 2-week quarantine period might need to be prolonged, while asymptomatic patients should be closely monitored.

• This paper assesses the early socio-medical response to COVID-19 in Nigeria, with a focus on the first 100 days after the index case. • The incidence of COVID-19 grows steadily in Nigeria, moving from an imported case and elitist pattern to community transmission, spreading across the states of the federation. • The paper presents a concise response framework to highlight the various multisectoral responses to the pandemic. • The response is not without some challenges, including inadequate testing laboratories, under-testing, inadequate palliatives and economic stimuli. • The potential of an overwhelming COVID-19 upsurge is still imminent in Nigeria as the country is attempting to hurriedly open the economy. • A most important lesson is the impossibility of the usual medical tourism among Nigerian elites. The coronavirus disease of 2019 (COVID-19) pandemic shocked the world, overwhelming the health systems of even high-income countries. Predictably, the situation has elicited social and medical responses from the public and governments, respectively. Nigeria recorded an imported case from Italy on February 27, 2020. Hence, this paper assesses the early socio-medical response to COVID-19 in Nigeria in the first 100 days after the index case. The paper employs analytical methods and collates data from various media reports and official sources. The incidence of COVID-19 grew steadily in Nigeria, moving from an imported case and elitist pattern to community transmission. The case fatality stood at 2.8%. The country recorded an upsurge (52% of total cases) in the transmission of COVID-19 during the short period the lockdown was relaxed. This paper presents a concise response framework to highlight some specific multisectoral responses to the pandemic. A combination of social and medical responses to a large extent helped Nigeria curtail the spread of the virus. The potential of overwhelming COVID-19 is still imminent in Nigeria as the country is attempting to hurriedly open the economy, which could sacrifice public health gains for temporary economic gains. [ABSTRACT FROM AUTHOR]

This study aimed to observe the initial trend of imported COVID-19 cases in South Korea since the beginning of the outbreak. All imported cases were classified into 5 regions (China, Asia, Europe, Africa, and America) according to travel history and potential exposure to the COVID-19. The list of countries for which confirmed cases had a travel history (single visit, multiple visits) and presented, were used to estimate the potential "exposure countries" of confirmed cases. For better understanding of the overall imported cases, time differences (day) among 3 major steps (symptom onset, entry to South Korea, laboratory confirmation) were measured based on available data. From the first importation of a COVID-19 case on January 20th, a total of 171 imported cases have been officially reported in South Korea as of March 23rd 2020. The overall trend of importation has significantly changed during this period. Importation of confirmed cases were initially from China, and subsequently from other Asian countries. After that, importation from Europe rapidly increased, with importation from America also increasing. One hundred fifteen (81%) were confirmed within 7 days of symptom onset. One Hundred forty three (84.1%) imported cases were confirmed within a week after entry into South Korea. One hundred seven imported cases (75.9%) developed symptoms within 5 days before or after, entry to South Korea. Streamlined processes of detection, subsequent testing, isolation, and treatment by public health authority, was key in minimizing the risk of secondary transmission. [ABSTRACT FROM AUTHOR]

The impact of the drastic reduction in travel volume within mainland China in January and February 2020 was quantified with respect to reports of novel coronavirus (COVID-19) infections outside China. Data on confirmed cases diagnosed outside China were analyzed using statistical models to estimate the impact of travel reduction on three epidemiological outcome measures: (i) the number of exported cases, (ii) the probability of a major epidemic, and (iii) the time delay to a major epidemic. From 28 January to 7 February 2020, we estimated that 226 exported cases (95% confidence interval: 86,449) were prevented, corresponding to a 70.4% reduction in incidence compared to the counterfactual scenario. The reduced probability of a major epidemic ranged from 7% to 20% in Japan, which resulted in a median time delay to a major epidemic of two days. Depending on the scenario, the estimated delay may be less than one day. As the delay is small, the decision to control travel volume through restrictions on freedom of movement should be balanced between the resulting estimated epidemiological impact and predicted economic fallout. [ABSTRACT FROM AUTHOR]