Transmission of coronavirus disease(COVID-19)and other infectious diseases is a significant risk during dental procedures because most dental interventions involve aerosols or droplets that could contaminate the surro...Transmission of coronavirus disease(COVID-19)and other infectious diseases is a significant risk during dental procedures because most dental interventions involve aerosols or droplets that could contaminate the surrounding environment.Current protection guidelines to address the high risk of droplets,aerosols,and airborne particle transmission of COVID-19 in the dental office recommend minimizing aerosol-generating procedures.In this paper,an innovative mouth shield is presented that should minimize water backsplash from the air-water syringe during dental treatment.The mouth shield can be added to the personal protective equipment to provide the dental team with extra protection.It can be made of different materials,is straightforward,inexpensive,and safe to fabricate,and is easy to use.展开更多
By providing a means of separating the airborne emissions of patients from the air breathed by healthcare workers(HCWs),vented individual patient(VIP)hoods,a form of local exhaust ventilation(LEV),offer a new approach...By providing a means of separating the airborne emissions of patients from the air breathed by healthcare workers(HCWs),vented individual patient(VIP)hoods,a form of local exhaust ventilation(LEV),offer a new approach to reduce hospital-acquired infection(HAI).Results from recent studies have demonstrated that,for typical patient-emitted aerosols,VIP hoods provide protection at least equivalent to that of an N95 mask.Unlike a mask,hood performance can be easily monitored and HCWs can be alerted to failure by alarms.The appropriate use of these relatively simple devices could both reduce the reliance on personal protective equipment(PPE)for infection control and provide a low-cost and energy-efficient form of protection for hospitals and clinics.Although the development and deployment of VIP hoods has been accelerated by the coronavirus disease 2019(COVID-19)pandemic,these devices are currently an immature technology.In this review,we describe the state of the art of VIP hoods and identify aspects in need of further development,both in terms of device design and the protocols associated with their use.The broader concept of individual patient hoods has the potential to be expanded beyond ventilation to the provision of clean conditions for individual patients and personalized control over other environmental factors such as temperature and humidity.展开更多
The novel Coronavirus COVID-19 emerged in Wuhan,China in December 2019.COVID-19 has rapidly spread among human populations and other mammals.The outbreak of COVID-19 has become a global challenge.Mathematical models o...The novel Coronavirus COVID-19 emerged in Wuhan,China in December 2019.COVID-19 has rapidly spread among human populations and other mammals.The outbreak of COVID-19 has become a global challenge.Mathematical models of epidemiological systems enable studying and predicting the potential spread of disease.Modeling and predicting the evolution of COVID-19 epidemics in near real-time is a scientific challenge,this requires a deep understanding of the dynamics of pandemics and the possibility that the diffusion process can be completely random.In this paper,we develop and analyze a model to simulate the Coronavirus transmission dynamics based on Reservoir-People transmission network.When faced with a potential outbreak,decision-makers need to be able to trust mathematical models for their decision-making processes.One of the most considerable characteristics of COVID-19 is its different behaviors in various countries and regions,or even in different individuals,which can be a sign of uncertain and accidental behavior in the disease outbreak.This trait reflects the existence of the capacity of transmitting perturbations across its domains.We construct a stochastic environment because of parameters random essence and introduce a stochastic version of theReservoir-Peoplemodel.Then we prove the uniqueness and existence of the solution on the stochastic model.Moreover,the equilibria of the system are considered.Also,we establish the extinction of the disease under some suitable conditions.Finally,some numerical simulation and comparison are carried out to validate the theoretical results and the possibility of comparability of the stochastic model with the deterministic model.展开更多
BACKGROUND Understanding the transmission dynamics of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection among healthcare workers(HCWs)and their social contacts is crucial to plan appropriate risk-re...BACKGROUND Understanding the transmission dynamics of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection among healthcare workers(HCWs)and their social contacts is crucial to plan appropriate risk-reduction measures.AIM To analyze the socio-demographic risk factors and transmission of SARS-CoV-2 infection among HCWs in two tertiary care hospitals in Dubai,United Arab Emirates.METHODS The demographic and clinical characteristics were available for all HCWs in both facilities from the human resources department.A cross-sectional survey was conducted from January-April 2022 among HCWs who tested positive through Reverse Transcriptase Polymerase Chain Reaction of the nasopharyngeal swab for SARS-CoV-2 between March 2020 and August 2021 in two tertiary-level hospitals.The survey included questions on demographics,work profile,characteristics of coronavirus disease 2019(COVID-19),and infection among their household or co-workers.The survey also checked the knowledge and perception of participants on the infection prevention measures related to SARS-CoV-2.RESULTS Out of a total of 346 HCWs infected with SARS-CoV-2,286(82.7%)HCWs consented to participate in this study.From the sample population,150(52.5%)of participants were female,and a majority(230,80.4%)were frontline HCWs,including 121 nurses(121,42.4%).Only 48(16.8%)participants were fully vaccinated at the time of infection.Most infected HCWs(85%)were unaware of any unprotected exposure and were symptomatic at the time of testing(225,78.7%).Nearly half of the participants(140,49%)had co-infection among household,and nearly one-third(29.5%)had coinfection among three or more household.Another 108(37.8%)participants reported crossinfection among co-workers.The frontline HCWs were significantly more infected(25.1%vs 8.6%,P<0.001)compared to non-frontline HCWs.Another significant risk factor for a high infection rate was male sex(P<0.001).Among the infected frontline HCWs,a significantly higher proportion were male and shared accommodation with family(P<0.001).COVID-19 vaccination significantly reduced the infection rate(83.2%vs 16.8,P<0.001)among HCWs.Most participants(99.3%)were aware about importance of appropriate use of personal protective equipment.However,only 70%agreed with the efficacy of the COVID-19 vaccination in preventing an infection and severe disease.CONCLUSION The risk profiling of the HCWs infected with SARS-CoV-2 found that working at frontline and being male increase the rate of infection.COVID-19 vaccination can effectively reduce the rate of transmission of SARS-CoV-2 among HCWs.展开更多
Most of the progress in the development of single scale mathematical and computational models for the study of infectious disease dynamics which now span over a century is build on a body of knowledge that has been de...Most of the progress in the development of single scale mathematical and computational models for the study of infectious disease dynamics which now span over a century is build on a body of knowledge that has been developed to address particular single scale descriptions of infectious disease dynamics based on understanding disease transmission process.Although this single scale understanding of infectious disease dynamics is now founded on a body of knowledge with a long history,dating back to over a century now,that knowledge has not yet been formalized into a scientific theory.In this article,we formalize this accumulated body of knowledge into a scientific theory called the transmission mechanism theory of disease dynamics which states that at every scale of organization of an infectious disease system,disease dynamics is determined by transmission as the main dynamic disease process.Therefore,the transmission mechanism theory of disease dynamics can be seen as formalizing knowledge that has been inherent in the study of infectious disease dynamics using single scale mathematical and computational models for over a century now.The objective of this article is to summarize this existing knowledge about single scale modelling of infectious dynamics by means of a scientific theory called the transmission mechanism theory of disease dynamics and highlight its aims,assumptions and limitations.展开更多
BACKGROUND:To assess the efficacy of the epidemic prevention measures of the“closed-loop”system adopted by the Beijing 2022 Olympic Winter Games(BOWG).METHODS:We retrospectively collected and analyzed information,in...BACKGROUND:To assess the efficacy of the epidemic prevention measures of the“closed-loop”system adopted by the Beijing 2022 Olympic Winter Games(BOWG).METHODS:We retrospectively collected and analyzed information,including age,sex,nationality,vaccination status,date of diagnosis,and date of entry,from 280 SARS-CoV-2-positive individuals identified during the BOWG.A susceptibility-exposed-infectious-remove model was employed to evaluate the effectiveness of epidemic prevention strategies on controlling the spread of SARS-CoV-2 under different scenarios during the BOWG.RESULTS:Regarding SARS-CoV-2-positive cases,97.9%were imported,and 96.4%were asymptomatic.The median age was 37 years(range:29–47 years),and 73.9%were male,with the majority of cases being broadcasters and European attendees.Regarding vaccination status,93.5%were fully vaccinated,and six cases were considered to have been infected in the closed-loop system during the BOWG.Assuming that the BOWG adopted a semi-closed-loop management system,the cumulative number of confirmed cases would be 1,137 for quick quarantine measures(3 d later)implemented and 5,530 for delayed quarantine measures(9 d later)implemented.This modeling revealed that stringent pandemic prevention measures and closed-loop management effectively controlled the spread of SARS-CoV-2 during the BOWG.CONCLUSION:Imported cases are considered the main risk factor for SARS-CoV-2 transmission during mass gatherings,but a comprehensive closed-loop system could minimize transmission among attendees and general personnel.展开更多
We specifically addressed the persistent challenge of dengue in endemic regions,highlighting the potential seriousness of dengue infection through vertical trans-mission.Vertical dengue transmission has been well docu...We specifically addressed the persistent challenge of dengue in endemic regions,highlighting the potential seriousness of dengue infection through vertical trans-mission.Vertical dengue transmission has been well documented,particularly in hyper-endemic regions,including Ecuador.Herein,we present a neonate diagno-sed with congenital dengue and review similar cases from previously published reports.Although congenital dengue is commonly infected with severe serotypes of DENV(DENV-1 and DENV-2)infections,favorable outcomes are generally observed.展开更多
文摘Transmission of coronavirus disease(COVID-19)and other infectious diseases is a significant risk during dental procedures because most dental interventions involve aerosols or droplets that could contaminate the surrounding environment.Current protection guidelines to address the high risk of droplets,aerosols,and airborne particle transmission of COVID-19 in the dental office recommend minimizing aerosol-generating procedures.In this paper,an innovative mouth shield is presented that should minimize water backsplash from the air-water syringe during dental treatment.The mouth shield can be added to the personal protective equipment to provide the dental team with extra protection.It can be made of different materials,is straightforward,inexpensive,and safe to fabricate,and is easy to use.
文摘By providing a means of separating the airborne emissions of patients from the air breathed by healthcare workers(HCWs),vented individual patient(VIP)hoods,a form of local exhaust ventilation(LEV),offer a new approach to reduce hospital-acquired infection(HAI).Results from recent studies have demonstrated that,for typical patient-emitted aerosols,VIP hoods provide protection at least equivalent to that of an N95 mask.Unlike a mask,hood performance can be easily monitored and HCWs can be alerted to failure by alarms.The appropriate use of these relatively simple devices could both reduce the reliance on personal protective equipment(PPE)for infection control and provide a low-cost and energy-efficient form of protection for hospitals and clinics.Although the development and deployment of VIP hoods has been accelerated by the coronavirus disease 2019(COVID-19)pandemic,these devices are currently an immature technology.In this review,we describe the state of the art of VIP hoods and identify aspects in need of further development,both in terms of device design and the protocols associated with their use.The broader concept of individual patient hoods has the potential to be expanded beyond ventilation to the provision of clean conditions for individual patients and personalized control over other environmental factors such as temperature and humidity.
基金2023年度教育部人文社会科学研究青年基金项目(23YJCZH303):交通和用地协同发展背景下城市轨道站域传染病传播的影响机制和风险识别研究世界银行全球环境基金GEF国际合作项目(7204890):Consultancy for Summary Reports and Multimedia Dissemination for GEF6 China SCIAP Project(TOD中国可持续城市发展试点项目总结报告)中国博士后科学基金面上资助项目(2020M680332):基于复杂适应系统理论的城市适灾景观勘测模型与规划响应研究。
文摘The novel Coronavirus COVID-19 emerged in Wuhan,China in December 2019.COVID-19 has rapidly spread among human populations and other mammals.The outbreak of COVID-19 has become a global challenge.Mathematical models of epidemiological systems enable studying and predicting the potential spread of disease.Modeling and predicting the evolution of COVID-19 epidemics in near real-time is a scientific challenge,this requires a deep understanding of the dynamics of pandemics and the possibility that the diffusion process can be completely random.In this paper,we develop and analyze a model to simulate the Coronavirus transmission dynamics based on Reservoir-People transmission network.When faced with a potential outbreak,decision-makers need to be able to trust mathematical models for their decision-making processes.One of the most considerable characteristics of COVID-19 is its different behaviors in various countries and regions,or even in different individuals,which can be a sign of uncertain and accidental behavior in the disease outbreak.This trait reflects the existence of the capacity of transmitting perturbations across its domains.We construct a stochastic environment because of parameters random essence and introduce a stochastic version of theReservoir-Peoplemodel.Then we prove the uniqueness and existence of the solution on the stochastic model.Moreover,the equilibria of the system are considered.Also,we establish the extinction of the disease under some suitable conditions.Finally,some numerical simulation and comparison are carried out to validate the theoretical results and the possibility of comparability of the stochastic model with the deterministic model.
文摘BACKGROUND Understanding the transmission dynamics of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection among healthcare workers(HCWs)and their social contacts is crucial to plan appropriate risk-reduction measures.AIM To analyze the socio-demographic risk factors and transmission of SARS-CoV-2 infection among HCWs in two tertiary care hospitals in Dubai,United Arab Emirates.METHODS The demographic and clinical characteristics were available for all HCWs in both facilities from the human resources department.A cross-sectional survey was conducted from January-April 2022 among HCWs who tested positive through Reverse Transcriptase Polymerase Chain Reaction of the nasopharyngeal swab for SARS-CoV-2 between March 2020 and August 2021 in two tertiary-level hospitals.The survey included questions on demographics,work profile,characteristics of coronavirus disease 2019(COVID-19),and infection among their household or co-workers.The survey also checked the knowledge and perception of participants on the infection prevention measures related to SARS-CoV-2.RESULTS Out of a total of 346 HCWs infected with SARS-CoV-2,286(82.7%)HCWs consented to participate in this study.From the sample population,150(52.5%)of participants were female,and a majority(230,80.4%)were frontline HCWs,including 121 nurses(121,42.4%).Only 48(16.8%)participants were fully vaccinated at the time of infection.Most infected HCWs(85%)were unaware of any unprotected exposure and were symptomatic at the time of testing(225,78.7%).Nearly half of the participants(140,49%)had co-infection among household,and nearly one-third(29.5%)had coinfection among three or more household.Another 108(37.8%)participants reported crossinfection among co-workers.The frontline HCWs were significantly more infected(25.1%vs 8.6%,P<0.001)compared to non-frontline HCWs.Another significant risk factor for a high infection rate was male sex(P<0.001).Among the infected frontline HCWs,a significantly higher proportion were male and shared accommodation with family(P<0.001).COVID-19 vaccination significantly reduced the infection rate(83.2%vs 16.8,P<0.001)among HCWs.Most participants(99.3%)were aware about importance of appropriate use of personal protective equipment.However,only 70%agreed with the efficacy of the COVID-19 vaccination in preventing an infection and severe disease.CONCLUSION The risk profiling of the HCWs infected with SARS-CoV-2 found that working at frontline and being male increase the rate of infection.COVID-19 vaccination can effectively reduce the rate of transmission of SARS-CoV-2 among HCWs.
基金financial support from South Africa National Research Foundation(NRF)Grant No.IPRR(UID 132608).
文摘Most of the progress in the development of single scale mathematical and computational models for the study of infectious disease dynamics which now span over a century is build on a body of knowledge that has been developed to address particular single scale descriptions of infectious disease dynamics based on understanding disease transmission process.Although this single scale understanding of infectious disease dynamics is now founded on a body of knowledge with a long history,dating back to over a century now,that knowledge has not yet been formalized into a scientific theory.In this article,we formalize this accumulated body of knowledge into a scientific theory called the transmission mechanism theory of disease dynamics which states that at every scale of organization of an infectious disease system,disease dynamics is determined by transmission as the main dynamic disease process.Therefore,the transmission mechanism theory of disease dynamics can be seen as formalizing knowledge that has been inherent in the study of infectious disease dynamics using single scale mathematical and computational models for over a century now.The objective of this article is to summarize this existing knowledge about single scale modelling of infectious dynamics by means of a scientific theory called the transmission mechanism theory of disease dynamics and highlight its aims,assumptions and limitations.
基金National Key R&D Program of China(2022YFC3006201)Beijing Public Health High-level Scholars Development Program(2022-1-001)。
文摘BACKGROUND:To assess the efficacy of the epidemic prevention measures of the“closed-loop”system adopted by the Beijing 2022 Olympic Winter Games(BOWG).METHODS:We retrospectively collected and analyzed information,including age,sex,nationality,vaccination status,date of diagnosis,and date of entry,from 280 SARS-CoV-2-positive individuals identified during the BOWG.A susceptibility-exposed-infectious-remove model was employed to evaluate the effectiveness of epidemic prevention strategies on controlling the spread of SARS-CoV-2 under different scenarios during the BOWG.RESULTS:Regarding SARS-CoV-2-positive cases,97.9%were imported,and 96.4%were asymptomatic.The median age was 37 years(range:29–47 years),and 73.9%were male,with the majority of cases being broadcasters and European attendees.Regarding vaccination status,93.5%were fully vaccinated,and six cases were considered to have been infected in the closed-loop system during the BOWG.Assuming that the BOWG adopted a semi-closed-loop management system,the cumulative number of confirmed cases would be 1,137 for quick quarantine measures(3 d later)implemented and 5,530 for delayed quarantine measures(9 d later)implemented.This modeling revealed that stringent pandemic prevention measures and closed-loop management effectively controlled the spread of SARS-CoV-2 during the BOWG.CONCLUSION:Imported cases are considered the main risk factor for SARS-CoV-2 transmission during mass gatherings,but a comprehensive closed-loop system could minimize transmission among attendees and general personnel.
文摘We specifically addressed the persistent challenge of dengue in endemic regions,highlighting the potential seriousness of dengue infection through vertical trans-mission.Vertical dengue transmission has been well documented,particularly in hyper-endemic regions,including Ecuador.Herein,we present a neonate diagno-sed with congenital dengue and review similar cases from previously published reports.Although congenital dengue is commonly infected with severe serotypes of DENV(DENV-1 and DENV-2)infections,favorable outcomes are generally observed.