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1.
Cell Chem Biol ; 30(3): 261-277.e8, 2023 03 16.
Article in English | MEDLINE | ID: covidwho-2288731

ABSTRACT

Pulmonary fibrosis is a typical sequela of coronavirus disease 2019 (COVID-19), which is linked with a poor prognosis for COVID-19 patients. However, the underlying mechanism of pulmonary fibrosis induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Here, we demonstrated that the nucleocapsid (N) protein of SARS-CoV-2 induced pulmonary fibrosis by activating pulmonary fibroblasts. N protein interacted with the transforming growth factor ß receptor I (TßRI), to disrupt the interaction of TßRI-FK506 Binding Protein12 (FKBP12), which led to activation of TßRI to phosphorylate Smad3 and boost expression of pro-fibrotic genes and secretion of cytokines to promote pulmonary fibrosis. Furthermore, we identified a compound, RMY-205, that bound to Smad3 to disrupt TßRI-induced Smad3 activation. The therapeutic potential of RMY-205 was strengthened in mouse models of N protein-induced pulmonary fibrosis. This study highlights a signaling pathway of pulmonary fibrosis induced by N protein and demonstrates a novel therapeutic strategy for treating pulmonary fibrosis by a compound targeting Smad3.


Subject(s)
COVID-19 , Pulmonary Fibrosis , Animals , Mice , COVID-19/complications , Fibrosis , Nucleocapsid Proteins/therapeutic use , Pulmonary Fibrosis/complications , Pulmonary Fibrosis/drug therapy , SARS-CoV-2
2.
Vaccines (Basel) ; 11(3)2023 Mar 01.
Article in English | MEDLINE | ID: covidwho-2288476

ABSTRACT

This study aims to explore the relationship between the doses of inactivated COVID-19 vaccines received and SARS-CoV-2 Omicron infection in the real-world setting, so as to preliminarily evaluate the protective effect induced by COVID-19 vaccination. We conducted a test-negative case-control study and recruited the test-positive cases and test-negative controls in the outbreak caused by Omicron BA.2 in April 2022 in Guangzhou, China. All the participants were 3 years and older. The vaccination status between the case group and the control group was compared in the vaccinated and all participants, respectively, to estimate the immune protection of inactivated COVID-19 vaccines. After adjusting for sex and age, compared with a mere single dose, full vaccination of inactivated COVID-19 vaccines (OR = 0.191, 95% CI: 0.050 to 0.727) and booster vaccination (OR = 0.091, 95% CI: 0.011 to 0.727) had a more superior protective effect. Compared with one dose, the second dose was more effective in males (OR = 0.090), as well as two doses (OR = 0.089) and three doses (OR = 0.090) among individuals aged 18-59. Whereas, when compared with the unvaccinated, one dose (OR = 7.715, 95% CI: 1.904 to 31.254) and three doses (OR = 2.055, 95% CI: 1.162 to 3.635) could contribute to the increased risk of Omicron infection after adjusting for sex and age. Meanwhile, by contrast with unvaccinated individuals, the result of increased risk was also manifested in the first dose in males (OR = 12.400) and one dose (OR = 21.500), two doses (OR = 1.890), and a booster dose (OR = 1.945) in people aged 18-59. In conclusion, the protective effect of full and booster vaccination with inactivated COVID-19 vaccines exceeded the incomplete vaccination, of which three doses were more effective. Nevertheless, vaccination may increase the risk of Omicron infection compared with unvaccinated people. This may result from the transmission traits of BA.2, the particularity and stronger protection awareness of the unvaccinated population, as well as the ADE effect induced by the decrease of antibody titers after a long time of vaccination. It is crucial to explore this issue in depth for the formulation of future COVID-19 vaccination strategies.

3.
Sci Rep ; 13(1): 2779, 2023 02 16.
Article in English | MEDLINE | ID: covidwho-2276347

ABSTRACT

596 million SARS-CoV-2 cases have been reported and over 12 billion vaccine doses have been administered. As vaccination rates increase, a gap in knowledge exists regarding appropriate thresholds for escalation and de-escalation of workplace COVID-19 preventative measures. We conducted 133,056 simulation experiments, evaluating the spread of SARS-CoV-2 virus in hypothesized working environments subject to COVID-19 infections from the community. We tested the rates of workplace-acquired infections based on applied isolation strategies, community infection rates, methods and scales of testing, non-pharmaceutical interventions, variant predominance, vaccination coverages, and vaccination efficacies. When 75% of a workforce is vaccinated with a 70% efficacious vaccine against infection, then no masking or routine testing + isolation strategies are needed to prevent workplace-acquired omicron variant infections when the community infection rate per 100,000 persons is ≤ 1. A CIR ≤ 30, and ≤ 120 would result in no workplace-acquired infections in this same scenario against the delta and alpha variants, respectively. Workforces with 100% worker vaccination can prevent workplace-acquired infections with higher community infection rates. Identifying and isolating workers with antigen-based SARS-CoV-2 testing methods results in the same or fewer workplace-acquired infections than testing with slower turnaround time polymerase chain reaction methods. Risk migration measures such as mask-wearing, testing, and isolation can be relaxed, or escalated, in commensurate with levels of community infections, workforce immunization, and risk tolerance. The interactive heatmap we provide can be used for immediate, parameter-based case count predictions to inform institutional policy making. The simulation approach we have described can be further used for future evaluation of strategies to mitigate COVID-19 spread.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , COVID-19 Testing , COVID-19/epidemiology , COVID-19/prevention & control , Workplace
4.
J Med Virol ; 95(2): e28447, 2023 02.
Article in English | MEDLINE | ID: covidwho-2269954

ABSTRACT

Omicron BA.2.2 is the dominant variant in the Hong Kong outbreak since December 31, 2021. There is no study reporting the weekly symptom profile after infection. In this retrospective study, participants who tested positive for SARS-CoV-2 after December 31, 2021, and registered in the telemedicine system between March 14 and May 6, 2022, were analyzed. Among registered 12 950 self-quarantined COVID-19-positive patients, 11 776 symptomatic patients were included for weekly symptom profile analysis. A total of 4718 (40.1%) patients reported symptoms in the first week after a positive test, 2501 (21.2%) in the second week, 1498 (12.7%) in the third week, 1048 (8.9%) in the fourth week, and 2011 (17.1%) in over 4 weeks. Cough was the most common symptom in all participants. Patients in the first week had higher odds of reporting fever (0.206, 95% confidence interval [CI]: 0.161-0.263, p < 0.001) and sore throat (0.228, 95% CI: 0.208-0.252, p < 0.001). Patients in over 4 weeks had higher odds of reporting fatigue (1.263, 95% CI: 1.139-1.402, p < 0.001). Further, having at least two vaccine doses linked to lower odds of having fever (0.675, 95% CI: 0.562-0.811, p < 0.001), but not associated with the presence of cough and fatigue. Diabetic patients had higher odds of reporting diarrhea (1.637, 95% CI: 1.351-1.982, p < 0.001). Symptoms from Omicron infection may last for more than 4 weeks and symptom profiles vary from week to week. Vaccination and comorbidity affect the symptom profiles.


Subject(s)
COVID-19 , Telemedicine , Humans , SARS-CoV-2 , Cough , Hong Kong , Retrospective Studies , Disease Outbreaks , Fatigue , Fever
5.
Biosaf Health ; 2022 Oct 28.
Article in English | MEDLINE | ID: covidwho-2262536

ABSTRACT

We analyzed variations in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome during a flight-related cluster outbreak of coronavirus disease 2019 (COVID-19) in Shenzhen, China, to explore the characteristics of SARS-CoV-2 transmission and intra-host single nucleotide variations (iSNVs) in a confined space. Thirty-three patients with COVID-19 were sampled, and 14 were resampled 3-31 days later. All 47 nasopharyngeal swabs were deep sequenced. iSNVs and similarities in the consensus genome sequence were analyzed. Three SARS-CoV-2 variants of concern, Delta (n=31), Beta (n=1), and C.1.2 (n=1), were detected among the 33 patients. The viral genome sequences from 30 Delta-positive patients had similar SNVs; 14 of these patients provided two successive samples. Overall, the 47 sequenced genomes contained 164 iSNVs. Of the 14 paired (successive) samples, the second samples (T2) contained more iSNVs (median: 3; 95% confidence interval [95%CI]: 2.77-10.22) than did the first samples (T1; median: 2; 95%CI: 1.63-3.74; Wilcoxon test, P=0.021). 38 iSNVs were detected in T1 samples, and only seven were also detectable in T2 samples. Notably, T2 samples from two of the 14 paired samples had additional mutations than the T1 samples. The iSNVs of the SARS-CoV-2 genome exhibited rapid dynamic changes during a flight-related cluster outbreak event. Intra-host diversity increased gradually with time, and new site mutations occurred in vivo without a population transmission bottleneck. Therefore, we could not determine the generational relationship from the mutation site changes alone.

6.
Vaccines (Basel) ; 11(2)2023 Feb 17.
Article in English | MEDLINE | ID: covidwho-2246828

ABSTRACT

This study aims to analyze the serum neutralization capacity against Delta and Omicron variants in three clusters of individuals, including those who had recovered from COVID-19 and those who had received two and three doses of inactivated vaccine. Pseudovirus neutralization tests were performed on serum samples. The neutralizing titers between different groups were compared using the Wilcoxon's signed-rank test. Among the two-dose vaccinees, the neutralization titers of the Omicron variant were reduced by approximately 3.1-fold compared to the wild-type virus (p < 0.05). Meanwhile, among the three-dose vaccinees, the neutralization titers for Delta and Omicron variants were 3.5-fold (p < 0.05) and 5.0-fold (p < 0.05) lower, respectively, as compared to the wild-type virus. In addition, among the recovering patients, the neutralization titers for Delta and Omicron variants were 3.9-fold (p < 0.05) and 29.1-fold (p < 0.05) lower, respectively, as compared to the wild-type virus. Overall, only 12.0% (11/92) of participants showed neutralizing titers against Omicron above the detection limit. The ability to neutralize wild-type pseudovirus was significantly boosted in three-dose vaccinees as compared to two-dose vaccinees. Sera from recovered patients showed greater neutralizing titers for the wild-type and Delta pseudoviruses than the two- and three-dose inactivated vaccine groups. The present study revealed a loss of neutralizing activity against the Omicron variant in almost all samples. Moreover, the immunization effect obtained through natural infection is more robust than that from the active immunization method of vaccination.

7.
Journal of Tropical Medicine ; 21(9):1209-1213, 2021.
Article in Chinese | GIM | ID: covidwho-2046827

ABSTRACT

Objective: To understand the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) specific IgM, IgC and IgA responses in corona Virus disease 2019(COVID-19) patients. Method: The SARS-CoV-2-specific IgM and IgG levels were determined by the enzyme-linked immunosorbent assay while IgA 1evels were detected by the chemiluminescence immune detection systems.

8.
J Clin Lab Anal ; 36(11): e24727, 2022 Nov.
Article in English | MEDLINE | ID: covidwho-2047649

ABSTRACT

BACKGROUND: Many rapid nucleic acid testing systems have emerged to halt the development and spread of COVID-19. However, so far relatively few studies have compared the diagnostic performance between these testing systems and conventional detection systems. Here, we performed a retrospective analysis to evaluate the clinical detection performance between SARS-CoV-2 rapid and conventional nucleic acid detection system. METHODS: Clinical detection results of 63,352 oropharyngeal swabs by both systems were finally enrolled in this analysis. Sensitivity (SE), specificity (SP), and positive and negative predictive value (PPV, NPV) of both systems were calculated to evaluate their diagnostic accuracy. Concordance between these two systems were assessed by overall, positive, negative percent agreement (OPA, PPA, NPA) and κ value. Sensitivity of SARS-CoV-2 rapid nucleic acid detection system (Daan Gene) was further analyzed with respect to the viral load of clinical specimens. RESULTS: Sensitivity of Daan Gene was slightly lower than that of conventional detection system (0.86 vs. 0.979), but their specificity was equivalent. Daan Gene had ≥98.0% PPV and NPV for SARS-CoV-2. Moreover, Daan Gene demonstrated an excellent test agreement with conventional detection system (κ = 0.893, p = 0.000). Daan Gene was 99.31% sensitivity for specimens with high viral load (Ct < 35) and 50% for low viral load (Ct ≥ 35). CONCLUSIONS: While showing an analytical sensitivity slightly below than that of conventional detection system, rapid nucleic acid detection system may be a diagnostic alternative to rapidly identify SARS-CoV-2-infected individuals with high viral loads and a powerful complement to current detection methods.


Subject(s)
COVID-19 , Nucleic Acids , Humans , SARS-CoV-2/genetics , COVID-19 Testing , COVID-19/diagnosis , Clinical Laboratory Techniques/methods , Retrospective Studies
9.
Journal of Tropical Medicine ; 20(10):1380-1385, 2020.
Article in Chinese | GIM | ID: covidwho-2011589

ABSTRACT

Objective: To analysis the related factors that influenced the elimination of virus in patients with coronavirus disease 2019 (COVID-19), and help with its prevention and control.

10.
Chin Med ; 17(1): 99, 2022 Aug 22.
Article in English | MEDLINE | ID: covidwho-2002204

ABSTRACT

OBJECTIVES: This study aimed to evaluate the effects of Chinese Medicine (CM) on the health condition of the post-COVID-19 patients, particularly with the CM Syndrome diagnosis and Body Constitutions (BC), as well as related clinical characteristics. METHODS: 150 participants who had COVID-19 and discharged from Hong Kong public hospitals were recruited. They were provided with three to six months of CM treatments, during which assessments were made per month and at follow-up on their CM syndromes, BC, lung functions, and other medical conditions. This study was divided into two parts: (1) Retrospective survey: medical history of participants during COVID-19 hospitalization was collected during the baseline visit; (2) Prospective observation and assessments: clinical symptoms, lung functions, and BC status were evaluated in participants receiving CM treatment based on syndrome differentiation and clinical symptoms. RESULTS: The median hospitalization period was 16 days. Symptoms were presented in 145 (96.6%) patients at the day they were diagnosed with COVID-19. Fever, fatigue, and dry cough were the most common symptoms, exhibiting in 59.3% (89 of 150), 55.3% (83 of 150), and 46% (70 of 150) participants, respectively. Among the 150 post-COVID patients, majority (71.3%) were of the two particular post-COVID CM Syndromes (Qi Deficiency of Lung and Spleen, and Qi and Yin Deficiency). Upon CM treatment, there was an observable increase in participants reaching a balanced BC (i.e. healthy body conditions). The increase was observed to be more prominent in those without the particular CM Syndromes compared to those with the CM Syndromes. Main clinical symptoms in participants with the CM Syndromes decreased upon CM treatment. Occurrence of fatigue also dropped after CM treatment though not all accompanied clinical symptoms were resolved fully. Further to the improvement in terms of CM assessments, lung functions of the participants were found to show improvement after treatment. Both the performance in 6MWT and scores in the LFQ improved upon CM treatments (P < 0.05). CONCLUSION: This study provided evidence for individualized CM treatment on COVID-19 rehabilitation concerning the clinical symptoms improvements, lung functions improvement, and achieving a balanced BC. It is believed that CM may be a key to further promote rehabilitation and resolution of residual symptoms. Long-term large scale follow-up studies on sub-categorising post-COVID patients according to different CM syndromes would be required to further elucidate treatment of persistent symptoms that may be associated with long-COVID.

11.
ACS Synth Biol ; 11(7): 2229-2237, 2022 07 15.
Article in English | MEDLINE | ID: covidwho-1921556

ABSTRACT

Rapid and flexible plasmid construct generation at scale is one of the most limiting first steps in drug discovery projects. These hurdles can partly be overcome by adopting modular DNA design principles, automated sequence fragmentation, and plasmid assembly. To this end we have designed a robust, multimodule golden gate based cloning platform for construct generation with a wide range of applications. The assembly efficiency of the system was validated by splitting sfGFP and sfCherry3C cassettes and expressing them in E. coli followed by fluorometric assessment. To minimize timelines and cost for complex constructs, we developed a software tool named FRAGLER (FRAGment recycLER) that performs codon optimization, multiple sequence alignment, and automated generation of fragments for recycling. To highlight the flexibility and robustness of the platform, we (i) generated plasmids for SarsCoV2 protein reagents, (ii) automated and parallelized assemblies, and (iii) built modular libraries of chimeric antigen receptors (CARs) variants. Applying the new assembly framework, we have greatly streamlined plasmid construction and increased our capacity for rapid generation of complex plasmids.


Subject(s)
COVID-19 , Escherichia coli , Cloning, Molecular , DNA/genetics , Escherichia coli/genetics , Genetic Vectors , Humans , Plasmids/genetics , RNA, Viral , SARS-CoV-2 , Synthetic Biology
12.
Int J Environ Res Public Health ; 19(13)2022 06 23.
Article in English | MEDLINE | ID: covidwho-1911338

ABSTRACT

The tremendous impact of the novel coronavirus (COVID-19) on societal, political, and economic rhythms has given rise to a significant overall shift from pre- to post-pandemic policies. Restrictions, stay-at-home regulations, and lockdowns have directly influenced day-to-day urban transportation flow. The rise of door-to-door services and the demand for visiting medical facilities, grocery stores, and restaurants has had a significant impact on urban transportation modal demand, further impacting zonal parking demand distribution. This study reviews the overall impacts of the pandemic on urban transportation with respect to a variety of policy changes in different cities. The parking demand shift was investigated by exploring the during- and post-COVID-19 parking policies of distinct metropolises. The detailed data related to Melbourne city parking, generated by the Internet of things (IoT), such as sensors and devices, are examined. Empirical data from 2019 (16 March to 26 May) and 2020 (16 March to 26 May) are explored in-depth using explanatory data analysis to demonstrate the demand and average parking duration shifts from district to district. The results show that the experimental zones of Docklands, Queensbery, Southbanks, Titles, and Princess Theatre areas have experienced a decrease in percentage change of vehicle presence of 29.2%, 36.3%, 37.7%, 23.7% and 40.9%, respectively. Furthermore, on-street level analysis of Princess Theatre zone, Lonsdale Street, Exhibition Street, Spring Street, and Little Bourke Street parking bays indicated a decrease in percentage change of vehicle presence of 38.7%, 56.4%, 12.6%, and 35.1%, respectively. In conclusion, future potential policymaking frameworks are discussed that could provide further guidance in stipulating epidemic prevention and control policies, particularly in relation to parking regulations during the pandemic.


Subject(s)
COVID-19 , COVID-19/epidemiology , Cities , Communicable Disease Control , Humans , SARS-CoV-2 , Transportation
13.
Chin Med ; 17(1): 42, 2022 Apr 02.
Article in English | MEDLINE | ID: covidwho-1822199

ABSTRACT

OBJECTIVE: To explore the effect of Ludangshen oral liquid for treatment of convalescent patients with coronavirus disease 2019 (COVID-19) with randomized, double-blind, placebo-controlled multicenter method. METHODS: 200 convalescent COVID-19 patients who had symptoms related to decreased digestive and respiratory function were randomly divided to either receive Ludangshen oral liquid or placebo for 2 weeks. The severity of clinical symptoms including fatigue, anorexia, abdominal distension, loose stools, and shortness of breath were assessed by visual analogue scale and observed at before and after treatment. The improvement and resolution rates of clinical symptoms were evaluated. Full analysis set (FAS) and per-protocol set (PPS) were used for statistical analyses. Adverse events were recorded during the study. RESULTS: 8 patients did not complete the study. After 2 weeks of treatment, both FAS and PPS results showed that patients in Ludangshen group had significantly lower score of fatigue, anorexia, loose stools, and shortness of breath than placebo group (P < 0.05), while there was no significant difference in distention (P > 0.05). The improvement rate of fatigue, anorexia, distension, loose stools and shortness of breath were significantly higher in Ludangshen group (P < 0.05), as well as the resolution rates (P < 0.05) except for shortness of breath (P > 0.05). There were two cases of adverse events, with one nose bleeding in Ludangshen group and one headache in placebo group. CONCLUSION: The study suggested that two weeks of Ludangshen oral liquid treatment may have certain effects for convalescent COVID-19 patients on improving digestive and respiratory symptoms including fatigue, anorexia, loose stools and shortness of breath, which may be one of the choices for management of convalescent COVID-19 patients with digestive and respiratory symptoms.

14.
Iranian Red Crescent Medical Journal ; 22(4), 2020.
Article in English | GIM | ID: covidwho-1726651

ABSTRACT

Background: Mainland China has adopted the most decisive and proactive measures to contain the SARS-CoV-2 epidemic, which helps control the spread of the virus across the country. Objectives: Early epidemiological investigations found that the SARS-CoV-2 epidemic was more critical in Hubei province (Hubei) than in rest parts of mainland China (Rest of China). A cross-sectional study was conducted to answer this urgent question and provide implications for the world.

15.
Emerg Microbes Infect ; 11(1): 552-555, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1655962

ABSTRACT

We identified an individual who was coinfected with two SARS-CoV-2 variants of concern, the Beta and Delta variants. The ratio of the relative abundance between the two variants was maintained at 1:9 (Beta:Delta) in 14 days. Furthermore, possible evidence of recombinations in the Orf1ab and Spike genes was found.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Recombination, Genetic , Spike Glycoprotein, Coronavirus/genetics
16.
Front Microbiol ; 12: 799150, 2021.
Article in English | MEDLINE | ID: covidwho-1643526

ABSTRACT

Purpose: To investigate and characterize the putative Elizabethkingia anophelis contaminant isolated from throat and anal swab samples of patients from three fever epidemic clusters, which were not COVID-19 related, in Shenzhen, China, during COVID-19 pandemic. Methods: Bacteria were cultured from throat (n = 28) and anal (n = 3) swab samples from 28 fever adolescent patients. The isolated bacterial strains were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) and the VITEK2 automated identification system. Nucleic acids were extracted from the patient samples (n = 31), unopened virus collection kits from the same manufacturer as the patient samples (n = 35, blank samples) and from unopened throat swab collection kits of two other manufacturers (n = 22, control samples). Metagenomic sequencing and quantitative real-time PCR (qPCR) detection were performed. Blood serum collected from patients (n = 13) was assessed for the presence of antibodies to E. anophelis. The genomic characteristics, antibiotic susceptibility, and heat resistance of E. anophelis isolates (n = 31) were analyzed. Results: The isolates were identified by MALDI-TOF/MS and VITEK2 as Elizabethkingia meningoseptica. DNA sequence analysis confirmed isolates to be E. anophelis. The patients' samples and blank samples were positive for E. anophelis. Control samples were negative for E. anophelis. The sera from a sub-sample of 13 patients were antibody-negative for isolated E. anophelis. Most of the isolates were highly homologous and carried multiple ß-lactamase genes (bla B, bla GOB, and bla CME). The isolates displayed resistance to nitrofurans, penicillins, and most ß-lactam drugs. The bacteria survived heating at 56°C for 30 min. Conclusion: The unopened commercial virus collection kits from the same manufacturer as those used to swab patients were contaminated with E. anophelis. Patients were not infected with E. anophelis and the causative agent for the fevers remains unidentified. The relevant authorities were swiftly notified of this discovery and subsequent collection kits were not contaminated. DNA sequence-based techniques are the definitive method for Elizabethkingia species identification. The E. anophelis isolates were multidrug-resistant, with partial heat resistance, making them difficult to eradicate from contaminated surfaces. Such resistance indicates that more attention should be paid to disinfection protocols, especially in hospitals, to avoid outbreaks of E. anophelis infection.

18.
J Med Virol ; 93(12): 6496-6505, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1544293

ABSTRACT

The COVID-19 epidemic is not only a medical issue but also a sophisticated social problem. We propose a network dynamics model of epidemic transmission introducing a heterogeneous control factor. The proposed model applied the classical susceptible- exposed-infectious-recovered model to the network based on effective distance and was modified by introducing a heterogeneous control factor with temporal and spatial characteristics. International aviation data were approximately used to estimate the flux fraction matrix, and the effective distance was calculated. Through parameter estimation and simulation, the theoretical values of the modified model fit well with practical values. By adjusting the parameters and observing the change of the results, we found that the modified model is more in line with the actual needs and has higher credibility in the comprehensive analysis. The assessment shows that the number of confirmed cases worldwide will reach about 20 million optimistically. In severe cases, the peak value will exceed 80 million, and the late stage of the epidemic shows a long tail shape, lasting more than one and a half years. The effective way to control the global epidemic is to strengthen international cooperation and to impose international travel restrictions and other measures.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , Communicable Disease Control/methods , Primary Prevention/methods , Computer Simulation , Humans , Physical Distancing , Quarantine , SARS-CoV-2
19.
Zhongguo Huanjing Kexue = China Environmental Science ; 41(8):3927, 2021.
Article in English | ProQuest Central | ID: covidwho-1498172

ABSTRACT

Based on the meteorological forecast data from the National Meteorological Bureau, this study developed an AERMOD-based pollution forecasting model for iron and steel plants, simulated air quality impacts of a typical iron and steel plant located in Hebei Province during the controlled period(from February to March in 2020) and the uncontrolled period(from April to October in 2020) of the COVID-19 epidemic, and validated the model with real monitoring air quality data. In case of adverse wind direction, the results showed that the average contribution of SO2, NOx and PM10 from the plant to three state-controlled monitoring stations were 20.19~33.81%, 17.49~23.46% and 2.02~2.69% respectively during the controlled period, and 13.43~21.01%, 11.09~20.92% and 1.20~2.22% during the uncontrolled period. The correlation coefficients between the forecast values of SO2, NOx and PM10 emission of the plant and the real monitoring values of the three state-controlled monitoring stations were higher in the controlled period(the highest values are 0.43,0.48 and 0.29, respectively, at individual monitoring station) compared with the uncontrolled period(the highest values are 0.42,0.39 and 0.07, respectively) due to the less interference from other anthropogenic emission sources during the controlled period.

20.
JAMIA Open ; 4(3): ooaa074, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1402392

ABSTRACT

OBJECTIVES: We developed COVID-19 Outbreak Simulator (https://ictr.github.io/covid19-outbreak-simulator/) to quantitatively estimate the effectiveness of preventative and interventive measures to prevent and battle COVID-19 outbreaks for specific populations. MATERIALS AND METHODS: Our simulator simulates the entire course of infection and transmission of the virus among individuals in heterogeneous populations, subject to operations and influences, such as quarantine, testing, social distancing, and community infection. It provides command-line and Jupyter notebook interfaces and a plugin system for user-defined operations. RESULTS: The simulator provides quantitative estimates for COVID-19 outbreaks in a variety of scenarios and assists the development of public health policies, risk-reduction operations, and emergency response plans. DISCUSSION: Our simulator is powerful, flexible, and customizable, although successful applications require realistic estimation and robustness analysis of population-specific parameters. CONCLUSION: Risk assessment and continuity planning for COVID-19 outbreaks are crucial for the continued operation of many organizations. Our simulator will be continuously expanded to meet this need.

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