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1.
Journal of Hazardous Materials ; : 128239, 2022.
Article in English | ScienceDirect | ID: covidwho-1610835

ABSTRACT

Face mask has become an essential and effective apparatus to protect human beings from air pollution, especially the air-borne pathogens. However, most commercial face masks can hardly achieve good particulate matters (PMs) and high bactericidal efficacy concurrently. Herein, a bilayer structured composite filter medium with built-in antimicrobial activities was constructed by combining cotton woven modified by magnetron sputtered Ag/Zn coatings and electrospun poly(vinylidene fluoride)/polystyrene (PVDF/PS) nanofibers. With the benefit of external moisture, an electrical stimulation was generated inside the composite fabric and thus endowed the fabric antimicrobial function. The resultant composite fabric presented conspicuous performance for integrated air pollution control, high filtration performance towards PM0.3 (99.1%, 79.2Pa) and exceptional interception ratio against Escherichia coli (99.64%) and Staphylococcus aureus (98.75%) within 20min contact. The high efficiency contact sterilization function of the bilayer fabric could further potentially promote disinfection and reuse of the filter media. This work may provide a new perspective on designing high-performance face mask media for public health protection.

2.
ISPRS International Journal of Geo-Information ; 10(12):836, 2021.
Article in English | MDPI | ID: covidwho-1580707

ABSTRACT

During the COVID-19 lockdown in Wuhan, transportation, industrial production and other human activities declined significantly, as did the NO2 concentration. In order to assess the relative contributions of different factors to reductions in air pollutants, we implemented sensitivity experiments by Random Forest (RF) models, with the comparison of the contributions of meteorological conditions, human mobility, and emissions from industry and households between different periods. In addition, we conducted scenario analyses to suggest an appropriate limit for control of human mobility. Different mechanisms for air pollutants were shown in the pre-pandemic, pre-lockdown, lockdown, and post-pandemic periods. Wind speed and the Within-city Migration index, representing intra-city mobility intensity, were excluded from stepwise multiple linear models in the pre-lockdown and lockdown periods. The results of sensitivity experiments show that, in the COVID-19 lockdown period, 73.3% of the reduction can be attributed to decreased human mobility. In the post-pandemic period, meteorological conditions control about 42.2% of the decrease, and emissions from industry and households control 40.0%, while human mobility only contributes 17.8%. The results of the scenario analysis suggest that the priority of restriction should be given to human mobility within the city than other kinds of human mobility. The reduction in the NO2 concentration tends to be smaller when human mobility within the city decreases by more than 70%. A limit of less than 40% on the control of the human mobility can achieve a better effect, especially in cities with severe traffic pollution.

3.
Vaccine ; 2021 Nov 18.
Article in English | MEDLINE | ID: covidwho-1569117

ABSTRACT

OBJECTIVE: To conduct a nationwide evaluation of vaccine bidding, procurement and distribution management for understanding and improving the current situation well in mainland China. METHODS: An institution survey was carried out to collect information on tendering, procurement, distribution and related issues to vaccines by structured questionnaires administered to 31 provinces in mainland China from April to July 2019. RESULTS: In 13 (41.9%) of 31 provinces, centralized bidding of National Immunization Program (NIP) vaccines was accomplished, and others conducted independent tendering and purchasing in 2018. For non-NIP vaccines, all provinces implemented unified bidding at the provincial level and over half (18, 58.1%) of them chose provincial public resource trading platforms, but their modes varied over provinces. Then procurement was undertaken by the district-level centers for disease control and prevention (CDC) while they were unable to choose the best option of too many vaccines targeted by the province-level CDC for local populations. The distribution modes of NIP and non-National Immunization Program (non-NIP) vaccines were similar overall in a province but very different over provinces. Main mode was that CDCs at different levels delivered about two thirds (64.5%) of NIP vaccines distribution and more than one third (35.5%) of non-NIP vaccines. Another distribution mode was occupied as fully buying the service from third parties in 3 municipalities. Some provinces mixed both modes, too. The total distribution volume of vaccines was 430.7 million doses in 2018. The top five non-NIP vaccines delivered in 2018 were human rabies vaccine, varicella vaccine, EV71 hand foot mouth disease vaccine, hepatitis B vaccine and influenza vaccine. CONCLUSION: The vaccine biding, procurement and distribution management varied over provinces in mainland China in 2018, especially for non-NIP vaccines. Specific policies and measures should be developed for different regions to improve the immunization management better.

4.
Front Med (Lausanne) ; 8: 697338, 2021.
Article in English | MEDLINE | ID: covidwho-1555527

ABSTRACT

Covid-19, Coronavirus disease 2019; ARDS, Acute respiratory distress syndrome; ECMO, Extracorporeal Membrane Oxygenation; WHO, World Health Organization; ICUs, Intensive care units. Acute respiratory distress syndrome (ARDS) is a fatal comorbidity of critically ill patients with COVID-19, who often end up on respiratory support. However, the safety and effectiveness of Extracorporeal Membrane Oxygenation (ECMO) in the treatment of COVID-19 remains to be elucidated at present. Here, we report on nine patients who received ECMO due to severe SARS-CoV-2 infection in Wuhan, China. Our initial experiences suggest that carefully selecting patients, as well as management by a well-trained team, are critical to implementing ECMO in patients with COVID-19. More randomized controlled trials with larger sample sizes are needed to evaluate the usefulness of ECMO in patients with COVID-19.

5.
International Communications in Heat and Mass Transfer ; : 105748, 2021.
Article in English | ScienceDirect | ID: covidwho-1509827

ABSTRACT

Here we evaluate the transport of respiratory droplets that carry SARS-CoV-2 through central air handling systems in multiroom buildings. Respiratory droplet size modes arise from the bronchioles representing the lungs and lower respiratory tract, the larynx representing the upper respiratory tract including vocal cords, or the oral cavity. The size distribution of each mode remains largely conserved, although the magnitude of each droplet mode changes as infected individuals breathe, speak, sing, laugh, cough, and sneeze. Here we evaluate how each type of respiratory droplet transits central ventilation systems and the implications thereof for infectivity of COVID-19. We find that while larger oral droplets can transmit through the air handling systems, their size and concentration are greatly reduced with but few oral droplets leaving the source room. In contrast, the smaller droplets that originate from the bronchioles and larynx are much more effective in transiting through the air handling system into connected rooms. This suggests that ratio of lower respiratory or deep lung infections increases relative to upper respiratory infections in rooms connected by central air handling systems. Also, increasing the temperature and humidity in the range considered after the droplets have achieved an “equilibrium” size reduces the probability of infection.

6.
International Communications in Heat and Mass Transfer ; : 105746, 2021.
Article in English | ScienceDirect | ID: covidwho-1509826

ABSTRACT

Here we evaluate the influence of mucus layers on the evaporation time and transport of enveloped viruses, including SARS-CoV-2. Enveloped viruses must remain moist to be fully infective. Yet, the simple but enduring Wells model based on water droplets divides respiratory droplets into either quickly evaporated aerosolized particles termed droplet nuclei (<10 s) or liquid droplets that fall to the nearest surface, leaving no physical mechanism for airborne transmission of fully infective enveloped viruses over large distances (greater than a few meters). Yet, the role of mucus layers on evaporation times has not been considered even though the formation of mucus shells around liquid cores of respiratory droplets has been shown experimentally. Here we show that mucus shells increase the drying time by orders of magnitude so that enveloped virions may remain well hydrated and, thus, fully infective at substantial distances. This provides a mechanism by which infective enveloped virus particles can transmit as aerosols within buildings and between buildings over extended distances. This analysis is important because public health agencies typically follow the Wells model to establish health policies including social/physical distancing guidelines.

7.
Front Psychol ; 12: 747557, 2021.
Article in English | MEDLINE | ID: covidwho-1507070

ABSTRACT

Aim: Since the 2019 coronavirus disease (COVID-19) outbreak, medical staff have faced greater psychological stress and are prone to psychological problems such as anxiety and depression, as confirmed by several studies. This study further clarifies the psychological status of Chinese medical staff during the stable phase of the pandemic through a cross-sectional investigation in a large population sample in northern China. Methods: Subjects: Clinical frontline medical staff from seven hospitals in Liaoning Province were recruited from November 2020 to February 2021. Research Tools: The research tools used were the Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), Simplified Coping Style Questionnaire (SCSQ), and General Status Questionnaire. Statistical Analysis: SPSS 22.0, ANOVA variance analysis, and multiple logistics regression were used for statistical analysis. P-values of <0.05 indicated significant statistical differences. Results: A total of 3,144 medical staff completed the survey (599 men [19.1%] and 2,545 women [80.9%]; 1,020 doctors [32.4%] and 2,124 nurses [67.6%]). Among all subjects, the rates of anxiety and depression were 21.1% (663/3, 144) and 43.9% (1,381/3,144), respectively. Multiple logistic comparative analysis revealed that age (OR = 1.272, 95% CI = 1.036-1.561, P = 0.022), the need for psychological counseling (OR = 1.566, 95% CI = 1.339-1.830, P < 0.001), and the coexistence of depression (OR = 0.050, 95% CI = 0.038-0.066, P < 0.001) were significantly associated with anxiety. Coexisting anxiety was also associated with the occurrence of depression (OR = 0.050, 95% CI = 0.038-0.065, P < 0.001). Conclusions: In the later stages of the pandemic in China, the occurrence rates of anxiety and depression among medical staff remain high. In addition to age, there is little correlation between anxiety or depression and general factors such as gender and profession. As a special group, medical staff show different psychological changes at various times during a stressful event. Concerning for the psychological needs of medical staff and different psychologically oriented policy implementation are needed.

8.
Front Biosci (Landmark Ed) ; 26(10): 789-798, 2021 10 30.
Article in English | MEDLINE | ID: covidwho-1498508

ABSTRACT

Background: The coronavirus disease 2019 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected more than 210 million individuals globally and resulted in over 4 million deaths since the first report in December 2019. The early use of traditional Chinese medicine (TCM) for light and ordinary patients, can rapidly improve symptoms, shorten hospitalization days and reduce severe cases transformed from light and normal. Many TCM formulas and products have a wide application in treating infectious and non-infectious diseases. Polygonum cuspidatum Sieb. et Zucc. (P. cuspidatum), is an important Traditional Chinese Medicine with actions of clearing away heat and eliminating dampness, draining the gallbladder to relieve jaundice, removing blood stasis to alleviate pain, resolving phlegm and arrest cough. In the search for anti-SARS-CoV-2, P. cuspidatum was recommended as as a therapeutic drug of COVID-19 pneumonia.In this study, we aimed to identifies P. cuspidatum is the potential broad-spectrum inhibitor for the treatment of coronaviruses infections. Methods: In the present study , we infected human malignant embryonal rhabdomyoma (RD) cells with the OC43 strain of the coronavirus, which represent an alternative model for SARS-CoV-2 and then employed the cell viability assay kit for the antiviral activity. We combined computer aided virtual screening to predicte the binding site and employed Surface plasmon resonance analysis (SPR) to comfirm the interaction between drugs and coronavirus. We employed fluorescence resonance energy transfer technology to identify drug's inhibition in the proteolytic activity of 3CLpro and Plpro. Results: Based on our results, polydatin and resveratrol derived from P. cuspidatum significantly suppressed HCoV-OC43 replication. 50% inhibitory concentration (IC50) values of polydatin inhibited SARS-CoV-2 Mpro and Plpro, MERS Mpro and Plpro were 18.66, 125, 14.6 and 25.42 µm, respectively. IC50 values of resveratrol inhibited SARS-CoV-2 Mpro and Plpro, MERS Mpro and Plpro were 29.81 ,60.86, 16.35 and19.04 µM, respectively. Finally, SPR assay confirmed that polydatin and resveratrol had high affinity to SARS-CoV-2, SARS-CoV 3Clpro, MERS-CoV 3Clpro and PLpro protein. Conclusions: we identified the antiviral activity of flavonoids polydatin and resveratrol on RD cells. Polydatin and resveratrol were found to be specific and selective inhibitors for SARS-CoV-2, 3CLpro and PLpro, viral cysteine proteases. In summary, this study identifies P. cuspidatum as the potential broad-spectrum inhibitor for the treatment of coronaviruses infections.


Subject(s)
Drugs, Chinese Herbal/chemistry , Fallopia japonica/chemistry , Glucosides/pharmacology , Resveratrol/pharmacology , SARS-CoV-2/drug effects , Stilbenes/pharmacology , Virus Replication/drug effects , Antiviral Agents/pharmacology , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19/virology , Cell Line, Tumor , Cell Survival/drug effects , Glucosides/metabolism , HEK293 Cells , Host-Pathogen Interactions/drug effects , Humans , Medicine, Chinese Traditional/methods , Pandemics , Protein Binding , Resveratrol/metabolism , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Stilbenes/metabolism , Surface Plasmon Resonance/methods , Viral Proteins/metabolism
9.
iScience ; 24(10): 103205, 2021 Oct 22.
Article in English | MEDLINE | ID: covidwho-1446744

ABSTRACT

T cell exhaustion and dysfunction are hallmarks of severe COVID-19. To gain insights into the pathways underlying these alterations, we performed a comprehensive transcriptome analysis of peripheral-blood-mononuclear-cells (PBMCs), spleen, lung, kidney, liver, and heart obtained at autopsy from COVID-19 patients and matched controls, using the nCounter CAR-T-Characterization panel. We found substantial gene alterations in COVID-19-impacted organs, especially the lung where altered TCR repertoires are noted. Reduced TCR repertoires are also observed in PBMCs of severe COVID-19 patients. ENTPD1/CD39, an ectoenzyme defining exhausted T-cells, is upregulated in the lung, liver, spleen, and PBMCs of severe COVID-19 patients where expression positively correlates with markers of vasculopathy. Heightened ENTPD1/CD39 is paralleled by elevations in STAT-3 and HIF-1α transcription factors; and by markedly reduced CD39-antisense-RNA, a long-noncoding-RNA negatively regulating ENTPD1/CD39 at the post-transcriptional level. Limited TCR repertoire and aberrant regulation of ENTPD1/CD39 could have permissive roles in COVID-19 progression and indicate potential therapeutic targets to reverse disease.

10.
Journal of Portfolio Management ; 47(9):159-177, 2021.
Article in English | ProQuest Central | ID: covidwho-1395040

ABSTRACT

This article synthesizes recent and ongoing finance and economics research on pandemic and disaster risk related to COVID-19. Characterized by pronounced market movements and extreme volatility, the unprecedented disruption to the economy in early 2020 has inspired a rich, burgeoning literature on the financial and economic ramifications of pandemic risk. Financial economists have cultivated fresh perspectives regarding the transmission of pandemic-induced uncertainty to financial markets via channels related to the beliefs and behaviors of investors as well as corporate strategies and outcomes. These findings also highlight the imperative role of government policy responses in regulating the market volatility triggered by large-scale disasters such as the pandemic. In this article, the authors take stock of this emerging literature, focusing on the implications for volatility and risk management. In doing so, they discuss the unique nature of the uncertainty induced by COVID-19 relative to that of past crises. They also review cutting-edge studies that use innovative analytical approaches and novel sources of data, offering fruitful avenues for future research. TOPICS: Tail risks, financial crises and financial market history, big data/machine learning Key Findings ▪ We synthesize recent and ongoing research in the finance and economics literature on pandemic and disaster risk related to COVID-19 and discuss the implications for asset pricing, volatility, and risk management. ▪ Pandemic-induced uncertainty led to extreme market movements in early 2020. We explore possible channels, such as investor beliefs and behaviors and corporate strategies, through which this risk was transmitted to the financial markets. ▪ Lessons learned from the recent pandemic will continue to have implications for volatility and risk management, even after the pandemic ends.

11.
PLoS One ; 15(8): e0238490, 2020.
Article in English | MEDLINE | ID: covidwho-1388885

ABSTRACT

SARS-CoV-2 is still rampaging throughout the world while the many evolutionary studies on it are simultaneously springing up. Researchers have simply utilized the public RNA-seq data to find out the so-called SNPs in the virus genome. The evolutionary analyses were largely based on these mutations. Here, we claim that we reliably detected A-to-G RNA modifications in the RNA-seq data of SARS-CoV-2 with high signal to noise ratios, presumably caused by the host's deamination enzymes. Intriguingly, since SARS-CoV-2 is an RNA virus, it is technically impossible to distinguish SNPs and RNA modifications from the RNA-seq data alone without solid evidence, making it difficult to tell the evolutionary patterns behind the mutation spectrum. Researchers should clarify their biological significance before they automatically regard the mutations as SNPs or RNA modifications. This is not a problem for DNA organisms but should be seriously considered when we are investigating the RNA viruses.


Subject(s)
Betacoronavirus/genetics , Evolution, Molecular , Polymorphism, Single Nucleotide , RNA, Viral/genetics , Base Sequence , COVID-19 , Coronavirus Infections , Humans , Mutation Rate , Pandemics , Pneumonia, Viral , RNA-Seq , SARS-CoV-2
12.
BMC Public Health ; 21(1): 1370, 2021 07 10.
Article in English | MEDLINE | ID: covidwho-1304398

ABSTRACT

BACKGROUND: The COVID-19 related lockdown and home confinement might have an important impact on the quality of life in enterprise workers. We investigated the quality of life during the epidemic in enterprise workers who just returned to work, and assessed its potential influencing factors to have a better understanding of the impact of COVID-19 epidemic lockdown and home confinement. METHODS: This was a cross-sectional study of enterprise workers conducted in Deqing and Taizhou, Zhejiang Province, China. The Chinese version of EQ5D was used to assess life quality, and information about general characteristics and COVID-19 related factors was collected by a structured questionnaire, which was distributed through the social application "WeChat". Multiple liner regression was used to investigate potential influencing factors. RESULTS: A total of 2420 participants were enrolled, 59.5% of which worked in Deqing. About 50% of the participants reported worries about the COVID-2019 epidemic and 40.2% had a centralized or home quarantine during the epidemic. The mean EQ-5D score and VAS were 0.990 and 93.5. Multiple liner regression showed that the quality of life measures was related to physical activities (ß = 0.006) and keeping home ventilation (ß = 0.063) in Deqing, and were related to wearing a mask when going out (ß = 0.014), keeping home ventilation (ß = 0.061), other marital status (ß = - 0.011), worry about the epidemic (ß = - 0.005) and having a centralized or home quarantine (ß = - 0.005) in Taizhou. CONCLUSIONS: The quality of life for returning enterprise workers in areas with different risks of COVID-19 was affected by different factors. Associated factors identified from this study would help develop proper intervention measures for enterprise workers to reduce the impact of large-scale public health events like the COVID-19 on their quality of life.


Subject(s)
COVID-19 , Epidemics , China/epidemiology , Communicable Disease Control , Cross-Sectional Studies , Humans , Quality of Life , SARS-CoV-2 , Surveys and Questionnaires
13.
Chin Med Sci J ; 36(1): 66-71, 2021 Mar 31.
Article in English | MEDLINE | ID: covidwho-1187235

ABSTRACT

In the era of coronavirus disease 2019 (COVID-19) pandemic, imported COVID-19 cases pose great challenges to many countries. Chest CT examination is considered to be complementary to nucleic acid test for COVID-19 detection and diagnosis. We report the first community infected COVID-19 patient by an imported case in Beijing, which manifested as nodular lesions on chest CT imaging at the early stage. Deep Learning (DL)-based diagnostic systems quantitatively monitored the progress of pulmonary lesions in 6 days and timely made alert for suspected pneumonia, so that prompt medical isolation was taken. The patient was confirmed as COVID-19 case after nucleic acid test, for which the community transmission was prevented timely. The roles of DL-assisted diagnosis in helping radiologists screening suspected COVID cases were discussed.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnostic imaging , Deep Learning , Lung/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Beijing , Community-Acquired Infections/diagnostic imaging , Humans , Male
14.
Materials Letters: X ; : 100074, 2021.
Article in English | ScienceDirect | ID: covidwho-1164235

ABSTRACT

At the beginning of 2020, the whole world suffered from the new coronavirus (COVID-19). Wearing a mask was believed to reduce the spread of the virus. The core material of a mask required good air permeability and efficient filtration. Electrospun materials may match these requirments. By electrospinning, we prepared polyvinyl butyral (PVB)/berberine hydrochloride (BH) membranes onto the spunbonded nonwovens. The composite meshes showed a porous structures, good air permeability (164±16 mm/s) and air filtration efficiency 96.4% for PM 0.3, 100% for PM 2.5, with pressure drop (108 Pa). Moreover, with the addition of BH, the as-spun membranes showed good antibacterial property for staphylococcus aureus. Furthermore, the prepared PVB/berberine membranes had good hydrophobicity with water contact angle higher than 140°. These results indicated that the fabricated PVB/berberine membranes have potential applications in mask and air filtration.

15.
Sci China Technol Sci ; : 1-10, 2021 Feb 10.
Article in English | MEDLINE | ID: covidwho-1092731

ABSTRACT

Mechanical ventilation is an effective medical means in the treatment of patients with critically ill, COVID-19 and other pulmonary diseases. During the mechanical ventilation and the weaning process, the conduct of pulmonary rehabilitation is essential for the patients to improve the spontaneous breathing ability and to avoid the weakness of respiratory muscles and other pulmonary functional trauma. However, inappropriate mechanical ventilation strategies for pulmonary rehabilitation often result in weaning difficulties and other ventilator complications. In this article, the mechanical ventilation strategies for pulmonary rehabilitation are studied based on the analysis of patient-ventilator interaction. A pneumatic model of the mechanical ventilation system is established to determine the mathematical relationship among the pressure, the volumetric flow, and the tidal volume. Each ventilation cycle is divided into four phases according to the different respiratory characteristics of patients, namely, the triggering phase, the inhalation phase, the switching phase, and the exhalation phase. The control parameters of the ventilator are adjusted by analyzing the interaction between the patient and the ventilator at different phases. A novel fuzzy control method of the ventilator support pressure is proposed in the pressure support ventilation mode. According to the fuzzy rules in this research, the plateau pressure can be obtained by the trigger sensitivity and the patient's inspiratory effort. An experiment prototype of the ventilator is established to verify the accuracy of the pneumatic model and the validity of the mechanical ventilation strategies proposed in this article. In addition, through the discussion of the patient-ventilator asynchrony, the strategies for mechanical ventilation can be adjusted accordingly. The results of this research are meaningful for the clinical operation of mechanical ventilation. Besides, these results provide a theoretical basis for the future research on the intelligent control of ventilator and the automation of weaning process.

16.
J Wound Care ; 30(Sup2): S12-S17, 2021 Feb 01.
Article in English | MEDLINE | ID: covidwho-1083226

ABSTRACT

COVID-19 is highly contagious and its rapid spread burdens the healthcare system. As the number of confirmed cases goes up, the shortage of medical resources has become a challenge. To avoid the collapse of the healthcare system during the fight with COVID-19, all healthcare workers, including wound care practitioners, should adapt to new roles and use any appropriate methods available to slow the spread of the virus. Integrating telemedicine into wound care during the outbreak helps maintain social distancing, preserve personal protective equipment and medical resources, and eliminate unnecessary exposure for both vulnerable patients and high-risk healthcare workers.


Subject(s)
Ambulatory Care , COVID-19/prevention & control , Diabetic Foot/therapy , Telemedicine , Triage , Wounds and Injuries/therapy , Cross Infection/prevention & control , Elective Surgical Procedures , Hospitalization , Humans , Infectious Disease Transmission, Patient-to-Professional/prevention & control , SARS-CoV-2
17.
Build Environ ; 197: 107633, 2021 Jun 15.
Article in English | MEDLINE | ID: covidwho-1056396

ABSTRACT

The COVID-19 pandemic has raised concern of viral spread within buildings. Although near-field transmission and infectious spread within individual rooms are well studied, the impact of aerosolized spread of SARS-CoV-2 via air handling systems within multiroom buildings remains unexplored. This study evaluates the concentrations and probabilities of infection for both building interior and exterior exposure sources using a well-mixed model in a multiroom building served by a central air handling system (without packaged terminal air conditioning). In particular, we compare the influence of filtration, air change rates, and the fraction of outdoor air. When the air supplied to the rooms comprises both outdoor air and recirculated air, we find filtration lowers the concentration and probability of infection the most in connected rooms. We find that increasing the air change rate removes virus from the source room faster but also increases the rate of exposure in connected rooms. Therefore, slower air change rates reduce infectivity in connected rooms at shorter durations. We further find that increasing the fraction of virus-free outdoor air is helpful, unless outdoor air is infective in which case pathogen exposure inside persists for hours after a short-term release. Increasing the outdoor air to 33% or the filter to MERV-13 decreases the infectivity in the connected rooms by 19% or 93% respectively, relative to a MERV-8 filter with 9% outdoor air based on 100 quanta/h of 5 µm droplets, a breathing rate of 0.48 m3/h, and the building dimensions and air handling system considered.

18.
J Mol Diagn ; 23(1): 10-18, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-988428

ABSTRACT

The prevalence and clinical relevance of viremia in patients with coronavirus disease 2019 (COVID-19) have not been well studied. A prospective cohort study was designed to investigate blood viral load and clearance kinetics in 52 patients (median age, 62 years; 31 [59.6%] male) and explore their association with clinical features and outcomes based on a novel one-step RT droplet digital PCR (RT-ddPCR). By using one-step RT-ddPCR, 92.3% (48 of 52) of this cohort was quantitatively detected with viremia. The concordance between the blood and oropharyngeal swab tests was 60.92% (53 of 87). One-step RT-ddPCR was tested with a 3.03% false-positive rate and lower 50% confidence interval of detection at 54.026 copies/mL plasma. There was no reduction in the blood viral load in all critical patients, whereas the general and severe patients exhibited a similar ability to clear the viral load. The viral loads in critical patients were significantly higher than those in their general and severe counterparts. Among the 52 study patients, 30 (58%) were discharged from the hospital. Among half of the 30 discharged patients, blood viral load remained positive, of which 76.9% (10 of 13) completely cleared their blood viral load at follow-up. Meanwhile, none of their close contacts had evidence of infection. Quantitative determination of the blood viral test is of great clinical significance in the management of patients with coronavirus disease 2019.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Severity of Illness Index , Viral Load/methods , Viremia/blood , Adult , Aged , Aged, 80 and over , COVID-19/mortality , COVID-19/pathology , Female , Humans , Male , Middle Aged , Oropharynx/virology , Prospective Studies , Real-Time Polymerase Chain Reaction , SARS-CoV-2/growth & development , SARS-CoV-2/immunology , Treatment Outcome , Viremia/mortality
19.
Soc Psychiatry Psychiatr Epidemiol ; 56(7): 1233-1240, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-970111

ABSTRACT

PURPOSE: To determine the prevalence of depression and anxiety and associated factors among returning workers with different epidemic experience in East China. METHODS: A cross-sectional study was conducted among 2435 employees from the enterprises located in Deqing (low-risk epidemic area) and Taizhou (high-risk epidemic area) of East China in March 2020. An online questionnaire covered information on sociodemographic and lifestyle factors as well as knowledge, attitude, behavior and experience about COVID-19. The Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7 (GAD-7) were applied to assess depression and anxiety symptoms, respectively. Logistic regression model was used to estimate adjusted odds ratios (aORs) and their 95% confidence intervals (CIs) for depression and anxiety symptoms associated with risk factors. RESULTS: The participants were aged 36.3 ± 9.2 years on average, and nearly half of them were female. Overall, the prevalence of depression, anxiety and both were 19.4%, 12.3% and 9.8%, and decreased with age. After adjustment for covariates, 16 or more years of education, being a white-collar worker or working in the high-risk epidemic area were significantly associated with increased risks of both depression and anxiety, in contract regular physical exercise was associated with decreased risks of both mental disorders. CONCLUSION: The depression and anxiety problems were prevalent among returning workers during the COVID-19 period. Targeted psychological interventions should be developed and implemented to improve their mental health.


Subject(s)
Anxiety , COVID-19 , Depression , Return to Work/psychology , Anxiety/epidemiology , China/epidemiology , Cross-Sectional Studies , Depression/epidemiology , Female , Humans , Surveys and Questionnaires
20.
BMJ Glob Health ; 5(11)2020 11.
Article in English | MEDLINE | ID: covidwho-922569

ABSTRACT

INTRODUCTION: The COVID-19 pandemic caused a healthcare crisis in China and continues to wreak havoc across the world. This paper evaluated COVID-19's impact on national and regional healthcare service utilisation and expenditure in China. METHODS: Using a big data approach, we collected data from 300 million bank card transactions to measure individual healthcare expenditure and utilisation in mainland China. Since the outbreak coincided with the 2020 Chinese Spring Festival holiday, a difference-in-difference (DID) method was employed to compare changes in healthcare utilisation before, during and after the Spring Festival in 2020 and 2019. We also tracked healthcare utilisation before, during and after the outbreak. RESULTS: Healthcare utilisation declined overall, especially during the post-festival period in 2020. Total healthcare expenditure and utilisation declined by 37.8% and 40.8%, respectively, while per capita expenditure increased by 3.3%. In a subgroup analysis, we found that the outbreak had a greater impact on healthcare utilisation in cities at higher risk of COVID-19, with stricter lockdown measures and those located in the western region. The DID results suggest that, compared with low-risk cities, the pandemic induced a 14.8%, 26.4% and 27.5% reduction in total healthcare expenditure in medium-risk and high-risk cities, and in cities located in Hubei province during the post-festival period in 2020 relative to 2019, an 8.6%, 15.9% and 24.4% reduction in utilisation services; and a 7.3% and 18.4% reduction in per capita expenditure in medium-risk and high-risk cities, respectively. By the last week of April 2020, as the outbreak came under control, healthcare utilisation gradually recovered, but only to 79.9%-89.3% of its pre-outbreak levels. CONCLUSION: The COVID-19 pandemic had a significantly negative effect on healthcare utilisation in China, evident by a dramatic decline in healthcare expenditure. While the utilisation level has gradually increased post-outbreak, it has yet to return to normal levels.


Subject(s)
Coronavirus Infections/epidemiology , Health Expenditures/statistics & numerical data , Health Services Accessibility , Patient Acceptance of Health Care/statistics & numerical data , Pneumonia, Viral/epidemiology , Betacoronavirus , COVID-19 , China/epidemiology , Humans , Pandemics , SARS-CoV-2
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