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1.
Math Biosci Eng ; 20(4): 7171-7192, 2023 02 10.
Article in English | MEDLINE | ID: covidwho-2288867

ABSTRACT

In this paper, we propose a two-patch model with border control to investigate the effect of border control measures and local non-pharmacological interventions (NPIs) on the transmission of COVID-19. The basic reproduction number of the model is calculated, and the existence and stability of the boundary equilibria and the existence of the coexistence equilibrium of the model are obtained. Through numerical simulation, when there are no unquarantined virus carriers in the patch-2, it can be concluded that the reopening of the border with strict border control measures to allow people in patch-1 to move into patch-2 will not lead to disease outbreaks. Also, when there are unquarantined virus carriers in patch-2 (or lax border control causes people carrying the virus to flow into patch-2), the border control is more strict, and the slower the growth of number of new infectious in patch-2, but the strength of border control does not affect the final state of the disease, which is still dependent on local NPIs. Finally, when the border reopens during an outbreak of disease in patch-2, then a second outbreak will happen.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Disease Outbreaks/prevention & control , Basic Reproduction Number , Computer Simulation
2.
CMAJ Open ; 10(2): E367-E378, 2022.
Article in English | MEDLINE | ID: covidwho-1798680

ABSTRACT

BACKGROUND: Globally, nonpharmaceutical interventions for COVID-19, including stay-at-home policies, limitations on gatherings and closure of public spaces, are being lifted. We explored the effect of lifting a stay-at-home policy on virus resurgence under different conditions. METHODS: Using confirmed case data from Toronto, Canada, between Feb. 24 and June 24, 2020, we ran a compartmental model with household structure to simulate the impact of the stay-at-home policy considering different levels of compliance. We estimated threshold values for the maximum number of contacts, probability of transmission and testing rates required for the safe reopening of the community. RESULTS: After the implementation of the stay-at-home policy, the contact rate outside the household fell by 39% (from 11.58 daily contacts to 7.11). The effective reproductive number decreased from 3.56 (95% confidence interval [CI] 3.02-4.14) on Mar. 12 to 0.84 (95% CI 0.79-0.89) on May 6. Strong adherence to stay-at-home policies appeared to prevent SARS-CoV-2 resurgence, but extending the duration of stay-at-home policies beyond 2 months had little added effect on cumulative cases (25 958 for 65 days of a stay-at-home policy and 23 461 for 95 days, by July 2, 2020) and deaths (1404 for 65 days and 1353 for 95 days). To avoid a resurgence, the average number of contacts per person per day should be kept below 9, with strict nonpharmaceutical interventions in place. INTERPRETATION: Our study demonstrates that the stay-at-home policy implemented in Toronto in March 2020 had a substantial impact on mitigating the spread of SARS-CoV-2. In the context of the early pandemic, before the emergence of variants of concern, reopening schools and workplaces was possible only with other nonpharmaceutical interventions in place.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , COVID-19/prevention & control , Canada/epidemiology , Humans , Pandemics/prevention & control , Policy
3.
Front Public Health ; 9: 722572, 2021.
Article in English | MEDLINE | ID: covidwho-1775836

ABSTRACT

Background: Diastasis rectus abdominis (DRA) is one of the common complications during pregnancy and post-partum, which has psychological and physical effects on post-partum women. Acupuncture, a worldwide alternative therapy, has attracted wide attention in preventing and treating diseases related to pregnancy and childbirth. This study aims to evaluate the efficacy of acupuncture combined with physical training in treating post-partum rectus muscle dissociation. Methods: This is a randomized, controlled trial of DRA in post-partum conducted at Hangzhou Hospital of Traditional Chinese Medicine Affiliated with Zhejiang University of Chinese Medicine. The primary purpose is to evaluate the effectiveness of acupuncture and physical training on DRA in post-partum women. The study will be conducted from March 2022 to March 2023. The acupuncture group received acupuncture and physical training (n = 48), the sham acupuncture group received sham acupuncture and physical training (n = 48), and the physical training group received physical training (n = 48). These experiments perform once/day, five times a week for 2 weeks, followed up for half a year after the end of the course of treatment. Our tests perform a course of treatment, which includes a total of 10 consecutive treatments. Furthermore, the patient will be followed up for half a year after the treatment. Primary and secondary indicators, including inter recti distance (IRD), linea alba (LA) tension, the MOS item short-form health survey (SF-36), short-form McGill pain questionnaire-2 (SF-MPQ-2), body mass index (BMI), waist-to-hip ratio (WHR), leeds dyspepsia questionnaire (LDQ), menstrual distress questionnaire (MDQ), 10 items of edinburgh post-natal depression scale (EPDS-10), the modified body self-image scale (MBIS), international consultation incontinence questionnaire short-form (ICIQ-SF) and hernia-related quality-of-life survey (HerQles), which will be evaluated before and after treatment and half a year after treatment. Adverse events and side effects during each treatment will be collected and recorded. Discussion: There is evidence that acupuncture and physical training can treat DRA in post-partum. In this study, we evaluate the effectiveness of acupuncture in post-partum with DRA.


Subject(s)
Acupuncture Therapy , Diastasis, Muscle , Female , Humans , Postpartum Period , Pregnancy , Randomized Controlled Trials as Topic , Rectus Abdominis
4.
Bull Math Biol ; 84(5): 55, 2022 04 04.
Article in English | MEDLINE | ID: covidwho-1772996

ABSTRACT

The sudden outbreak of SARS-CoV-2 has caused the shortage of medical resources around the world, especially in developing countries and underdeveloped regions. With the continuous increase in the duration of this disease, the control of migration of humans between regions or countries has to be relaxed. Based on this, we propose a two-patches mathematical model to simulate the transmission of SARS-CoV-2 among two-patches, asymptomatic infected humans and symptomatic infected humans, where a half-saturated detection rate function is also introduced to describe the effect of medical resources. By applying the methods of linearization and constructing a suitable Lyapunov function, the local and global stability of the disease-free equilibrium of this model without migration is obtained. Further, the existence of forward/backward bifurcation is analyzed, which is caused by the limited medical resources. This means that the elimination or prevalence of the disease no longer depends on the basic reproduction number but is closely related to the initial state of asymptomatic and symptomatic infected humans and the supply of medical resources. Finally, the global dynamics of the full model are discussed, and some numerical simulations are carried to explain the main results and the effects of migration and supply of medical resources on the transmission of disease.


Subject(s)
COVID-19 , SARS-CoV-2 , Basic Reproduction Number , COVID-19/epidemiology , Humans , Mathematical Concepts , Models, Biological
5.
Comput Biol Med ; 133: 104399, 2021 06.
Article in English | MEDLINE | ID: covidwho-1184909

ABSTRACT

At present, the global pandemic as it relates to novel coronavirus pneumonia is still a very difficult situation. Due to the recent outbreak of novel coronavirus pneumonia, novel chest X-ray (CXR) images that can be used for deep learning analysis are very rare. To solve this problem, we propose a deep learning framework that integrates a convolutional neural network and a capsule network. DenseCapsNet, a new deep learning framework, is formed by the fusion of a dense convolutional network (DenseNet) and the capsule neural network (CapsNet), leveraging their respective advantages and reducing the dependence of convolutional neural networks on a large amount of data. Using 750 CXR images of lungs of healthy patients as well as those of patients with other pneumonia and novel coronavirus pneumonia, the method can obtain an accuracy of 90.7% and an F1 score of 90.9%, and the sensitivity for detecting COVID-19 can reach 96%. These results show that the deep fusion neural network DenseCapsNet has good performance in novel coronavirus pneumonia CXR radiography detection.


Subject(s)
COVID-19 , Deep Learning , Algorithms , Humans , Neural Networks, Computer , SARS-CoV-2 , Tomography, X-Ray Computed , X-Rays
6.
ACS Appl Bio Mater ; 4(5): 3805-3810, 2021 05 17.
Article in English | MEDLINE | ID: covidwho-1172543

ABSTRACT

Rapid detection of SARS-CoV-2 RNA is critical for reducing the global transmission of COVID-19. Here, we report a simple and versatile assay for detection of SARS-CoV-2 RNA based on aligner-mediated cleavage-based strand displacement amplification (AMC-SDA). The entire amplification procedure takes less than 25 min without professional instruments or requirement of specific target sequences and can reach a limit of detection of attomolar RNA concentration. Using pseudovirus as mimicry of clinical SARS-CoV-2 positive samples, we achieved a diagnostic accuracy of 100% in 10 simulated samples (five positive and five negative). We anticipate that our method will provide a universal platform for rapid and accurate detection of emerging infectious diseases.


Subject(s)
COVID-19/diagnosis , Nucleic Acid Amplification Techniques , RNA, Viral/isolation & purification , SARS-CoV-2/isolation & purification , COVID-19 Nucleic Acid Testing , Humans , Oligonucleotides , Sensitivity and Specificity
7.
Anal Chem ; 93(7): 3325-3330, 2021 02 23.
Article in English | MEDLINE | ID: covidwho-1078273

ABSTRACT

Rapid tests for pathogen identification and spread assessment are critical for infectious disease control and prevention. The control of viral outbreaks requires a nucleic acid diagnostic test that is sensitive and simple and delivers fast and reliable results. Here, we report a one-pot direct reverse transcript loop-mediated isothermal amplification (RT-LAMP) assay of SARS-CoV-2 based on a lateral flow assay in clinical samples. The entire contiguous sample-to-answer workflow takes less than 40 min from a clinical swab sample to a diagnostic result without professional instruments and technicians. The assay achieved an accuracy of 100% in 12 synthetic and 12 clinical samples compared to the data from PCR-based assays. We anticipate that our method will provide a universal platform for rapid and point-of-care detection of emerging infectious diseases.


Subject(s)
COVID-19 Testing , COVID-19/diagnosis , Humans , Molecular Diagnostic Techniques , Nucleic Acid Amplification Techniques , Point-of-Care Testing , SARS-CoV-2 , Time Factors , Workflow
8.
Cell Res ; 31(2): 126-140, 2021 02.
Article in English | MEDLINE | ID: covidwho-1015005

ABSTRACT

The current coronavirus disease 2019 (COVID-19) pandemic presents a global public health challenge. The viral pathogen responsible, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), binds to the host receptor ACE2 through its spike (S) glycoprotein, which mediates membrane fusion and viral entry. Although the role of ACE2 as a receptor for SARS-CoV-2 is clear, studies have shown that ACE2 expression is extremely low in various human tissues, especially in the respiratory tract. Thus, other host receptors and/or co-receptors that promote the entry of SARS-CoV-2 into cells of the respiratory system may exist. In this study, we found that the tyrosine-protein kinase receptor UFO (AXL) specifically interacts with the N-terminal domain of SARS-CoV-2 S. Using both a SARS-CoV-2 virus pseudotype and authentic SARS-CoV-2, we found that overexpression of AXL in HEK293T cells promotes SARS-CoV-2 entry as efficiently as overexpression of ACE2, while knocking out AXL significantly reduces SARS-CoV-2 infection in H1299 pulmonary cells and in human primary lung epithelial cells. Soluble human recombinant AXL blocks SARS-CoV-2 infection in cells expressing high levels of AXL. The AXL expression level is well correlated with SARS-CoV-2 S level in bronchoalveolar lavage fluid cells from COVID-19 patients. Taken together, our findings suggest that AXL is a novel candidate receptor for SARS-CoV-2 which may play an important role in promoting viral infection of the human respiratory system and indicate that it is a potential target for future clinical intervention strategies.


Subject(s)
COVID-19/metabolism , Proto-Oncogene Proteins/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Respiratory Mucosa/cytology , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Bronchi/cytology , Bronchi/metabolism , Cell Line , Humans , Lung/cytology , Lung/metabolism , Models, Molecular , Protein Interaction Domains and Motifs , Proto-Oncogene Proteins/analysis , Receptor Protein-Tyrosine Kinases/analysis , Respiratory Mucosa/metabolism , SARS-CoV-2/chemistry , Spike Glycoprotein, Coronavirus/analysis , Virus Internalization , Axl Receptor Tyrosine Kinase
9.
Bull World Health Organ ; 98(12): 830-841D, 2020 Dec 01.
Article in English | MEDLINE | ID: covidwho-964002

ABSTRACT

OBJECTIVE: To design models of the spread of coronavirus disease-2019 (COVID-19) in Wuhan and the effect of Fangcang shelter hospitals (rapidly-built temporary hospitals) on the control of the epidemic. METHODS: We used data on daily reported confirmed cases of COVID-19, recovered cases and deaths from the official website of the Wuhan Municipal Health Commission to build compartmental models for three phases of the COVID-19 epidemic. We incorporated the hospital-bed capacity of both designated and Fangcang shelter hospitals. We used the models to assess the success of the strategy adopted in Wuhan to control the COVID-19 epidemic. FINDINGS: Based on the 13 348 Fangcang shelter hospitals beds used in practice, our models show that if the Fangcang shelter hospitals had been opened on 6 February (a day after their actual opening), the total number of COVID-19 cases would have reached 7 413 798 (instead of 50 844) with 1 396 017 deaths (instead of 5003), and the epidemic would have lasted for 179 days (instead of 71). CONCLUSION: While the designated hospitals saved lives of patients with severe COVID-19, it was the increased hospital-bed capacity of the large number of Fangcang shelter hospitals that helped slow and eventually stop the COVID-19 epidemic in Wuhan. Given the current global pandemic of COVID-19, our study suggests that increasing hospital-bed capacity, especially through temporary hospitals such as Fangcang shelter hospitals, to isolate groups of people with mild symptoms within an affected region could help curb and eventually stop COVID-19 outbreaks in communities where effective household isolation is not possible.


Subject(s)
COVID-19/epidemiology , COVID-19/therapy , Hospital Bed Capacity/statistics & numerical data , Mobile Health Units/organization & administration , China/epidemiology , Humans , Markov Chains , Models, Statistical , Pandemics , SARS-CoV-2
10.
Medicine (Baltimore) ; 99(29): e21334, 2020 Jul 17.
Article in English | MEDLINE | ID: covidwho-676910

ABSTRACT

RATIONALE: The outbreak of coronavirus disease 2019 (COVID-19) in 2019 has become a global pandemic. It is not known whether the disease is associated with a higher risk of infection in pregnant women or whether intrauterine vertical transmission can occur. We report 2 cases of pregnant women diagnosed with COVID-19. PATIENT CONCERNS: In all of Yichang city from January 20, 2020, to April 9, 2020, only 2 pregnant women, who were in the late stage of pregnancy, were diagnosed with COVID-19; one patient was admitted for fever with limb asthenia, and the other patient was admitted for abnormal chest computed tomography results. DIAGNOSES: Both pregnant women were diagnosed with COVID-19. INTERVENTIONS: After the medical staff prepared for isolation and protection, the 2 pregnant women quickly underwent cesarean sections. A series of tests, such as laboratory, imaging, and SARS-CoV-2 nucleic acid examinations, were performed on the 2 women with COVID-19 and their newborns. OUTCOMES: One of the 2 infected pregnant women had severe COVID-19, and the other had mild disease. Both babies were delivered by cesarean section. Both of the women with COVID-19 worsened 3 to 6 days after delivery. Chest computed tomography suggested that the lesions due to SARS-CoV-2 infection increased. These women began to exhibit fever or reduced blood oxygen saturation again. One of the 2 newborns was born prematurely, and the other was born at full term. Neither infant was infected with COVID-19, but both had increased prothrombin time and fibrinogen, lactate dehydrogenase, phosphocreatine kinase, and creatine kinase isoenzyme contents. LESSONS: SARS-CoV-2 infection was not found in the newborns born to the 2 pregnant women with COVID-19, but transient coagulation dysfunction and myocardial damage occurred in the 2 newborns. Effective management strategies for pregnant women with COVID-19 will help to control the outbreak of COVID-19 among pregnant women.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/diagnosis , Coronavirus Infections/virology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/virology , Adult , Asthenia/etiology , Betacoronavirus/isolation & purification , COVID-19 , Cesarean Section/methods , China/epidemiology , Coronavirus Infections/drug therapy , Disease Outbreaks/prevention & control , Female , Fever/etiology , Humans , Infant, Newborn/blood , Infant, Newborn/metabolism , Infectious Disease Transmission, Vertical/prevention & control , Pandemics , Pneumonia, Viral/drug therapy , Pregnancy , Pregnancy Complications, Infectious/epidemiology , Pregnancy Complications, Infectious/virology , Pregnancy Outcome/epidemiology , Premature Birth/epidemiology , SARS-CoV-2 , Thorax/diagnostic imaging , Tomography, X-Ray Computed/methods
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