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1.
Case Studies on Transport Policy ; : 101025, 2023.
Article in English | ScienceDirect | ID: covidwho-20230792

ABSTRACT

Despite the significance of the China e-commerce economy and the rapidly increasing air express service, there are few publications on the development of Chinese integrators that are significant contributors to the e-commerce boom. This research explores the network development of China's three integrators, namely, SF Express, TYO Express and China Post, and assesses the evolution of the networks during the pandemic period with the assistance of the complex network theory. It has been found that their networks underwent great development one year after the COVID-19 pandemic outbreak Their domestic networks are compared with the networks of the world-class integrators in the EU. It appears that the Chinese integrators operate networks with both hub-and-spoke and point-to-point features at their principal hubs (Hangzhou and Shenzhen of SF express, and Nanjing of China Post). SF Express' network in the Chinese domestic market demonstrates different topological features from the ones of its Chinese counterparts and the foreign integrators in Europe, with fewer one-way flights and at a higher density.

2.
Curr Psychol ; : 1-10, 2023 Apr 13.
Article in English | MEDLINE | ID: covidwho-2305449

ABSTRACT

Front-line nurses suffered unprecedented mental distress and severe insomnia during the COVID-19 pandemic. Present study aimed to explore the relationship between obsessive-compulsive symptoms and sleep quality and examine the potential mediating role of psychological flexibility between obsessive-compulsive symptoms and sleep quality. A total of 496 nurses from a Chinese large-scale Class 3 A Comprehensive Hospital were included in an online cross-sectional survey and completed the revised obsessive-compulsive inventory (OCI-R), Multidimensional Psychological Flexibility Inventory (MPFI) and Pittsburgh Sleep Quality Index (PSQI). As predicted, obsessive-compulsive symptoms were negatively associated with psychological flexibility and sleep quality, and psychological flexibility was positively associated with sleep quality. In addition, the relationship between obsessive-compulsive symptoms and sleep quality was partially mediated by psychological flexibility, which can provide some reference for the treatment of the obsessive-compulsive disorder (OCD) and insomnia, and lead to improvements in clinical and psychotherapy planning.

3.
Medicina (Kaunas) ; 59(4)2023 Apr 05.
Article in English | MEDLINE | ID: covidwho-2294158

ABSTRACT

Background and Objectives: COVID-19 patients are a psychologically vulnerable patient group who suffer from both physical symptoms and psychological problems. The present study is a psychoanalytic investigation of COVID-19 patients utilizing Lacan's desire theory. We aimed to explore the manner in which patients' desire is presented in their lived experience narratives and sought to discover factors which directly impacted on this process. Materials and Methods: In-depth semi-structural interviews were conducted with 36 COVID-19 patients in China. During each interview, participants narrated their lived experiences of COVID-19 infection. Emotions, metaphors, and behaviors in patient narratives were collated as the main points for psychoanalysis. Results: Our findings demonstrated that the desire for being a healthy person made patients emotionally sensitive to the social environment. Anxiety and obsessive behaviors emerged in the process, which reveals their desire for that which they lack. Furthermore, public fear with respect to COVID-19 was somehow converted to psychological pressure on COVID-19 patients. Thus, these patients attempted to "de-identify" their identity as "patients". Positive responses of COVID-19 patients to the external world included admiring medical personnel, government, and country, while negative responses included interpersonal conflicts or complaints about discrimination. Following the rules of the Other, COVID-19 patients were influenced by the Other's desire in constructing their own image of a healthy person. Conclusions: This study revealed COVID-19 patients' psychological need to rid themselves of the identity of "patient" at the individual and social level. Our findings have clinical implications in helping COVID-19 patients to reshape their identity and to live a normal life.


Subject(s)
COVID-19 , Psychoanalysis , Humans , Psychoanalytic Theory , Psychoanalysis/methods , Interpersonal Relations , China
4.
Journal of the Formosan Medical Association = Taiwan yi zhi ; 2023.
Article in English | EuropePMC | ID: covidwho-2254306

ABSTRACT

Background Data about changes in the characteristics of ED return visits before and after the COVID-19 outbreak are limited. This study aimed to report the differences on utility in ED return visits after the COVID-19 outbreak. Methods This retrospective cohort study was conducted from 2019 to 2020. Adult patients with ED return visits were included in the analysis. Variables including demographic characteristics, pre-comorbidities, triage levels, vital signs, chief complaints, management, and diagnosis were recorded and confirmed via a manual assessment. Results The proportion of patients with ED visits decreased by 23%. Hence, that of patients with ED return visits also reduced from 2580 to 2020 patients (22%) after the COVID-19 outbreak. The average age (60–57.8 years) of patients with return visits was significantly younger, and the proportion of female patients decreased remarkably. Further, the proportion of patients with chronic pre-existing diseases at the return visit significantly differed after the COVID-19 outbreak. The proportion of patients with chief complaints including dizziness, dyspnea, cough, vomiting, diarrhea, and chills during the return visits significantly differed before and after the COVID-19 pandemic. In the multivariable logistic regression model, age, high triage level were significantly associated with unfavorable outcome return visit. Conclusions The use of services in the ED has changed since the COVID-19 outbreak. Hence, the proportion of patients with unplanned return visits within 72 h decreased. After the COVID-19 outbreak, people are now cautious whether they should return to the ED, as in the pre-pandemic situation, or just treat conservatively at home.

5.
Pathogens ; 10(7)2021 Jul 03.
Article in English | MEDLINE | ID: covidwho-2262971

ABSTRACT

During the coronavirus disease 2019 (COVID-19) pandemic, several case studies demonstrated that many asymptomatic patients with COVID-19 underwent fluorine-18 fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) examination for various indications. However, there is a lack of literature to characterize the pattern of [18F]FDG PET/CT imaging on asymptomatic COVID-19 patients. Therefore, a systematic review to analyze the pulmonary findings of [18F]FDG PET/CT on asymptomatic COVID-19 patients was conducted. This systematic review was performed under the guidelines of PRISMA. PubMed, Medline, and Web of Science were used to search for articles for this review. Articles with the key words: "asymptomatic", "COVID-19", "[18F]FDG PET/CT", and "nuclear medicine" were searched for from 1 January 2020 to 20 May 2021. Thirty asymptomatic patients with COVID-19 were included in the eighteen articles. These patients had a mean age of 62.25 ± 14.85 years (male: 67.71 ± 12.00; female: 56.79 ± 15.81). [18F]FDG-avid lung lesions were found in 93.33% (28/30) of total patients. The major lesion was [18F]FDG-avid multiple ground-glass opacities (GGOs) in the peripheral or subpleural region in bilateral lungs, followed by the consolidation. The intensity of [18F]FDG uptake in multiple GGOs was 5.605 ± 2.914 (range from 2 to 12) for maximal standardized uptake value (SUVmax). [18F]FDG-avid thoracic lymph nodes (LN) were observed in 40% (12/40) of the patients. They mostly appeared in both mediastinal and hilar regions with an SUVmax of 5.8 ± 2.93 (range from 2.5 to 9.6). The [18F]FDG uptake was observed in multiple GGOs, as well as in the mediastinal and hilar LNs. These are common patterns in PET/CT of asymptomatic patients with COVID-19.

6.
J Formos Med Assoc ; 2023 Mar 15.
Article in English | MEDLINE | ID: covidwho-2254307

ABSTRACT

BACKGROUND: Data about changes in the characteristics of ED return visits before and after the COVID-19 outbreak are limited. This study aimed to report the differences on utility in ED return visits after the COVID-19 outbreak. METHODS: This retrospective cohort study was conducted from 2019 to 2020. Adult patients with ED return visits were included in the analysis. Variables including demographic characteristics, pre-comorbidities, triage levels, vital signs, chief complaints, management, and diagnosis were recorded and confirmed via a manual assessment. RESULTS: The proportion of patients with ED visits decreased by 23%. Hence, that of patients with ED return visits also reduced from 2580 to 2020 patients (22%) after the COVID-19 outbreak. The average age (60-57.8 years) of patients with return visits was significantly younger, and the proportion of female patients decreased remarkably. Further, the proportion of patients with chronic pre-existing diseases at the return visit significantly differed after the COVID-19 outbreak. The proportion of patients with chief complaints including dizziness, dyspnea, cough, vomiting, diarrhea, and chills during the return visits significantly differed before and after the COVID-19 pandemic. In the multivariable logistic regression model, age, high triage level were significantly associated with unfavorable outcome return visit. CONCLUSIONS: The use of services in the ED has changed since the COVID-19 outbreak. Hence, the proportion of patients with unplanned return visits within 72 h decreased. After the COVID-19 outbreak, people are now cautious whether they should return to the ED, as in the pre-pandemic situation, or just treat conservatively at home.

7.
Sci Total Environ ; 875: 162661, 2023 Jun 01.
Article in English | MEDLINE | ID: covidwho-2274043

ABSTRACT

The paper discusses the implementation of Hong Kong's tailor-made sewage surveillance programme led by the Government, which has demonstrated how an efficient and well-organized sewage surveillance system can complement conventional epidemiological surveillance to facilitate the planning of intervention strategies and actions for combating COVID-19 pandemic in real-time. This included the setting up of a comprehensive sewerage network-based SARS-CoV-2 virus surveillance programme with 154 stationary sites covering 6 million people (or 80 % of the total population), and employing an intensive monitoring programme to take samples from each stationary site every 2 days. From 1 January to 22 May 2022, the daily confirmed case count started with 17 cases per day on 1 January to a maximum of 76,991 cases on 3 March and dropped to 237 cases on 22 May. During this period, a total of 270 "Restriction-Testing Declaration" (RTD) operations at high-risk residential areas were conducted based on the sewage virus testing results, where over 26,500 confirmed cases were detected with a majority being asymptomatic. In addition, Compulsory Testing Notices (CTN) were issued to residents, and the distribution of Rapid Antigen Test kits was adopted as alternatives to RTD operations in areas of moderate risk. These measures formulated a tiered and cost-effective approach to combat the disease in the local setting. Some ongoing and future enhancement efforts to improve efficacy are discussed from the perspective of wastewater-based epidemiology. Forecast models on case counts based on sewage virus testing results were also developed with R2 of 0.9669-0.9775, which estimated that up to 22 May 2022, around 2,000,000 people (~67 % higher than the total number of 1,200,000 reported to the health authority, due to various constraints or limitations) had potentially contracted the disease, which is believed to be reflecting the real situation occurring in a highly urbanized metropolis like Hong Kong.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , SARS-CoV-2 , Wastewater-Based Epidemiological Monitoring , Sewage , Pandemics , Hong Kong/epidemiology
8.
Water Res ; 230: 119560, 2023 Feb 15.
Article in English | MEDLINE | ID: covidwho-2165952

ABSTRACT

The effective application of wastewater surveillance is dependent on testing capacity and sensitivity to obtain high spatial resolution testing results for a timely targeted public health response. To achieve this purpose, the development of rapid, high-throughput, and sensitive virus concentration methods is urgently needed. Various protocols have been developed and implemented in wastewater surveillance networks so far, however, most of them lack the ability to scale up testing capacity or cannot achieve sufficient sensitivity for detecting SARS-CoV-2 RNA at low prevalence. In the present study, using positive raw wastewater in Hong Kong, a PEG precipitation-based three-step centrifugation method was developed, including low-speed centrifugation for large particles removal and the recovery of viral nucleic acid, and medium-speed centrifugation for the concentration of viral nucleic acid. This method could process over 100 samples by two persons per day to reach the process limit of detection (PLoD) of 3286 copies/L wastewater. Additionally, it was found that the testing capacity could be further increased by decreasing incubation and centrifugation time without significantly influencing the method sensitivity. The entire procedure uses ubiquitous reagents and instruments found in most laboratories to obtain robust testing results. This high-throughput, cost-effective, and sensitive tool will promote the establishment of nearly real-time wastewater surveillance networks for valuable public health information.


Subject(s)
COVID-19 , Nucleic Acids , Humans , RNA, Viral , SARS-CoV-2 , Wastewater , Wastewater-Based Epidemiological Monitoring
9.
Int J Environ Res Public Health ; 19(23)2022 Nov 30.
Article in English | MEDLINE | ID: covidwho-2143148

ABSTRACT

Metaphor provides an important intellectual tool for communication about intense disease experiences. The present study aimed to investigate how COVID-19-infected persons metaphorically frame their lived experiences of COVID-19, and how the pandemic impacts on their mental health burden. In-depth semi-structured interviews were conducted with 33 patients afflicted with COVID-19. Metaphor analysis of patient narratives demonstrated that: (1) COVID-19 infection impacted patient conceptualization of themselves and the relationship between the "self" and the body, as well as social relationships. (2) Metaphors relating to physical experience, space and time, and integrative behaviors tended to be used by COVID-19 patients in a negative way, whereas war metaphors, family metaphors, temperature metaphors, and light metaphors were likely to express positive attitudes. (3) Patients preferred to employ conventional metaphors grounded on embodied sensorimotor experiences to conceptualize their extreme emotional experiences. This study has important implications with respect to the therapeutic function of metaphors in clinical communication between healthcare professionals and COVID-19 patients.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Metaphor , Communication , Pandemics , Health Personnel/psychology
11.
PLoS One ; 17(9): e0274247, 2022.
Article in English | MEDLINE | ID: covidwho-2039410

ABSTRACT

COVID-19 has caused negative emotional responses in patients, with significant mental health consequences for the infected population. The need for an in-depth analysis of the emotional state of COVID-19 patients is imperative. This study employed semi-structured interviews and the text mining method to investigate features in lived experience narratives of COVID-19 patients and healthy controls with respect to five basic emotions. The aim was to identify differences in emotional status between the two matched groups of participants. The results indicate generally higher complexity and more expressive emotional language in healthy controls than in COVID-19 patients. Specifically, narratives of fear, happiness, and sadness by COVID-19 patients were significantly shorter as compared to healthy controls. Regarding lexical features, COVID-19 patients used more emotional words, in particular words of fear, disgust, and happiness, as opposed to those used by healthy controls. Emotional disorder symptoms of COVID-19 patients at the lexical level tended to focus on the emotions of fear and disgust. They narrated more in relation to self or family while healthy controls mainly talked about others. Our automatic emotional discourse analysis potentially distinguishes clinical status of COVID-19 patients versus healthy controls, and can thus be used to predict mental health disorder symptoms in COVID-19 patients.


Subject(s)
COVID-19 , Mental Health , Data Mining , Emotions/physiology , Happiness , Humans
12.
J Asthma Allergy ; 15: 1005-1019, 2022.
Article in English | MEDLINE | ID: covidwho-1993634

ABSTRACT

Purpose: To develop and evaluate the effectiveness/clinical application of an eosinophil cationic protein-myeloperoxidase (ECP-MPO) test paper before and after treatment in patients with allergic rhinitis (AR). Patients and Methods: We included 40 controls and 106 AR patients who were enrolled in the Allergy Clinic of Renmin Hospital of Wuhan University. Total IgE, specific IgE and skin prick test (SPT) were detected in all participants. AR patients were treated with oral cetirizine hydrochloride for 14 days. The ECP-MPO test paper results, nasal secretion smear and eosinophil counts, rhinoconjunctivitis total nasal symptom score (TNSS), quality of life questionnaire (RQLQ), visual analogue scale (VAS), serum Th1/Th2/Th17 cytokine, and chemokine data were collected pre- and post-treatment. ECP concentrations in nasal secretions were assessed by ELISA. Pearson correlation test and Kappa consistency test were used for statistical analysis. Results: The post-treatment colour grade of the ECP-MPO test paper was lower in AR patients than the pre-treatment grade. The chromogenic grade correlated positively with the ECP concentration and the eosinophil count in nasal secretions both before and after treatment. Positive ECP-MPO test paper results were consistent with positive SPT, Der p-IgE and Der f-IgE result (Kappa values, 0.843, 0.810, 0.795, respectively). The pre- and post-treatment chromogenic grades correlated positively with the TNSS (r1=0·691; r2=0·539), RQLQ (r1=0·783; r2=0·625), and VAS (r1=0·703; r2=0·682) scores in AR patients. Conclusion: The ECP-MPO test paper can effectively detect ECP in nasal secretions, and its results are consistent with those from the SPT, Der p-IgE and Der f-IgE result. Its chromogenic grade can reflect the symptom severity and specific cytokine and chemokine levels in AR patients.

13.
Int J Environ Res Public Health ; 19(15)2022 08 02.
Article in English | MEDLINE | ID: covidwho-1969267

ABSTRACT

This study explored the emotional experiences of COVID-19 patients in China. Thirty-four patients diagnosed with COVID-19 participated in semi-structured telephone interviews. We used qualitative methods to investigate the distribution patterns and characteristics of patients' emotional experiences. The results indicated that emotional experiences showed different characteristics at different stages during isolation and treatment. COVID-19 patients' emotional discourse encompassed eight main themes, namely, feelings of shock at the diagnosis, yearning for future life, attachment to one's family, depression during the treatment, self-restriction due to probable contagiousness, powerlessness about the disease, open-mindedness about death, and faith in the joint efforts to fight COVID-19. These themes related to experiences concerning infection, isolation, outlook on life and death, stigma, and macro-identity. The findings suggest that the unexpected experience of COVID-19 infection exacerbated patients' negative emotions. COVID-19 patients' emotional stress stemmed from isolated environments, physiological effects of the disease, panic about the unknown, and realistic economic pressure. The government, medical staff, family members of patients, and the media should therefore work together to ensure proper emotional care for COVID-19 patients.


Subject(s)
COVID-19 , COVID-19/epidemiology , China/epidemiology , Emotions , Family , Humans , Qualitative Research
14.
Sci Total Environ ; 844: 157121, 2022 Oct 20.
Article in English | MEDLINE | ID: covidwho-1914987

ABSTRACT

Wastewater-based epidemiology (WBE) for the SARS-CoV-2 virus in wastewater treatment plants (WWTPs) has emerged as a cost-effective and unbiased tool for population-level testing in the community. In the present study, we conducted a 6-month wastewater monitoring campaign from three WWTPs of different flow rates and catchment area characteristics, which serve 28 % (2.1 million people) of Hong Kong residents in total. Wastewater samples collected daily or every other day were concentrated using ultracentrifugation and the SARS-CoV-2 virus RNA in the supernatant was detected using the N1 and E primer sets. The results showed significant correlations between the virus concentration and the number of daily new cases in corresponding catchment areas of the three WWTPs when using 7-day moving average values (Kendall's tau-b value: 0.227-0.608, p < 0.001). SARS-CoV-2 virus concentration was normalized to a fecal indicator using PMMoV concentration and daily flow rates, but the normalization did not enhance the correlation. The key factors contributing to the correlation were also evaluated, including the sampling frequency, testing methods, and smoothing days. This study demonstrates the applicability of wastewater surveillance to monitor overall SARS-CoV-2 pandemic dynamics in a densely populated city like Hong Kong, and provides a large-scale longitudinal reference for the establishment of the long-term sentinel surveillance in WWTPs for WBE of pathogens which could be combined into a city-wide public health observatory.


Subject(s)
COVID-19 , Water Purification , COVID-19/epidemiology , Hong Kong/epidemiology , Humans , Pandemics , RNA, Viral , SARS-CoV-2/genetics , Wastewater , Wastewater-Based Epidemiological Monitoring
15.
BMC Public Health ; 22(1): 1098, 2022 06 01.
Article in English | MEDLINE | ID: covidwho-1869078

ABSTRACT

BACKGROUND: Under the outbreak of Coronavirus disease 2019 (COVID-19), a structural equation model was established to determine the causality of important factors that affect Chinese citizens' COVID-19 prevention behavior. METHODS: The survey in Qingdao covered several communities in 10 districts and used the method of cluster random sampling. The research instrument used in this study is a self-compiled Chinese version of the questionnaire. Of the 1215 questionnaires, 1188 were included in our analysis. We use the rank sum test, which is a non-parametric test, to test the influence of citizens'basic sociodemographic variables on prevention behavior, and the rank correlation test to analyze the influencing factors of prevention behavior. IBM AMOS 24.0 was used for path analysis, including estimating regression coefficients and evaluating the statistical fits of the structural model, to further explore the causal relationships between variables. RESULTS: The result showed that the score in the prevention behavior of all citizens is a median of 5 and a quartile spacing of 0.31. The final structural equation model showed that the external support for fighting the epidemic, the demand level of health information, the cognition of (COVID-19) and the negative emotions after the outbreak had direct effects on the COVID-19 prevention behavior, and that negative emotions and information needs served as mediating variables. CONCLUSIONS: The study provided a basis for relevant departments to further adopt epidemic prevention and control strategies.


Subject(s)
COVID-19 , Asian People , COVID-19/epidemiology , COVID-19/prevention & control , China/epidemiology , Cognition , Humans , Surveys and Questionnaires
16.
Water Res ; 220: 118686, 2022 Jul 15.
Article in English | MEDLINE | ID: covidwho-1867893

ABSTRACT

To effectively control the ongoing outbreaks of fast-spreading SARS-CoV-2 variants, there is an urgent need to add rapid variant detection and discrimination methods to the existing sewage surveillance systems established worldwide. We designed eight assays based on allele-specific RT-qPCR for real-time allelic discrimination of eight SARS-CoV-2 variants (Alpha, Beta, Gamma, Delta, Omicron, Lambda, Mu, and Kappa) in sewage. In silico analysis of the designed assays for identifying SARS-CoV-2 variants using more than four million SARS-CoV-2 variant sequences yielded ∼100% specificity and >90% sensitivity. All assays could sensitively discriminate and quantify target variants at levels as low as 10 viral RNA copy/µL with minimal cross-reactivity to the corresponding nontarget genotypes, even for sewage samples containing mixtures of SARS-CoV-2 variants with differential abundances. Integration of this method into the routine sewage surveillance in Hong Kong successfully identified the Beta variant in a community sewage. Complete concordance was observed between the results of viral whole-genome sequencing and those of our novel assays in sewage samples that contained exclusively the Delta variant discharged by a clinically diagnosed COVID-19 patient living in a quarantine hotel. Our assays in this method also provided real-time discrimination of the newly emerging Omicron variant in sewage two days prior to clinical test results in another quarantine hotel in Hong Kong. These novel allelic discrimination assays offer a rapid, sensitive, and specific way for detecting multiple SARS-CoV-2 variants in sewage and can be directly integrated into the existing sewage surveillance systems.


Subject(s)
COVID-19 , SARS-CoV-2 , Alleles , Humans , SARS-CoV-2/genetics , Sewage
17.
Environ Sci Technol ; 56(12): 8875-8884, 2022 06 21.
Article in English | MEDLINE | ID: covidwho-1852362

ABSTRACT

Sewage surveillance is increasingly employed as a supplementary tool for COVID-19 control. Experiences learnt from large-scale trials could guide better interpretation of the sewage data for public health interventions. Here, we compared the performance of seven commonly used primer-probe sets in RT-qPCR and evaluated the usefulness in the sewage surveillance program in Hong Kong. All selected primer-probe sets reliably detected SARS-CoV-2 in pure water at 7 copies per µL. Sewage matrix did not influence RT-qPCR determination of SARS-CoV-2 concentrated from a small-volume sewage (30 mL) but introduced inhibitory impacts on a large-volume sewage (920 mL) with a ΔCt of 0.2-10.8. Diagnostic performance evaluation in finding COVID-19 cases showed that N1 was the best single primer-probe set, while the ORF1ab set is not recommended. Sewage surveillance using the N1 set for over 3200 samples effectively caught the outbreak trend and, importantly, had a 56% sensitivity and a 96% specificity in uncovering the signal sources from new cases and/or convalescent patients in the community. Our study paves the way for selecting detection primer-probe sets in wider applications in responding to the COVID-19 pandemic.


Subject(s)
COVID-19 , COVID-19/epidemiology , Humans , Pandemics , Public Health , RNA, Viral/analysis , SARS-CoV-2/genetics , Sensitivity and Specificity , Sewage
18.
Environ Health Perspect ; 130(5): 57008, 2022 05.
Article in English | MEDLINE | ID: covidwho-1846899

ABSTRACT

BACKGROUND: Sewage surveillance, by detecting SARS-CoV-2 virus circulation at the community level, has the potential to supplement individual surveillance for COVID-19. However, to date, there have been no reports about the large-scale implementation and validation of sewage surveillance for public health action. OBJECTIVE: Here, we developed a standardized approach for SARS-CoV-2 detection in sewage and applied it prospectively to supplement public health interventions. METHODS: We analyzed 1,169 sewage samples collected at 492 sites from December 2020 to March 2021. Forty-seven of 492 sites tested positive, 44 (94%) of them had traceable sources of viral signals in the corresponding sewershed, either from previously unsuspected but subsequently confirmed patients or recently convalescent patients or from both patient groups. RESULTS: Sewage surveillance had a sensitivity of 54%, a specificity of 95%, a positive predictive value of 53%, and a negative predictive value of 95% for identifying a previously unsuspected patient within a sewershed. Sewage surveillance in Hong Kong provided a basis for the statutory public health action to detect silent COVID-19 transmission. DISCUSSION: Considering the epidemiological data together with the sewage testing results, compulsory testing was conducted for individual residents at 27 positive sewage sites and uncovered total of 62 previously unsuspected patients, demonstrating the value of sewage surveillance in uncovering previously unsuspected patients in the community. Our study suggests that sewage surveillance could be a powerful management tool for the control of COVID-19. https://doi.org/10.1289/EHP9966.


Subject(s)
COVID-19 , COVID-19/epidemiology , Hong Kong/epidemiology , Humans , Public Health , SARS-CoV-2 , Sewage
19.
J Transp Geogr ; 99: 103298, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1729965

ABSTRACT

COVID-19 caused the vast majority of passenger flights to be grounded, but the crisis raised the importance of the network of dedicated cargo flights and, therefore, interest in its development. This paper aims to evaluate the Chinese scheduled freighter network (CSFN) via its topological properties and to explore its changes following the COVID-19 pandemic. Using spatial analysis with the complex network theory (CNT), the paper found that the CSFN displays small-world and scale-free network properties, similar to that of air passenger network. Hangzhou, Shenzhen and Nanjing are the dominant national hubs in the CSFN because they host the headquarters of many e-commerce giant enterprises and have relatively underutilized airport capacities. The CSFN has improved since the COVID-19 pandemic, with increased network average degree, clustering coefficient, and closeness, and reduced average path. These improvements were mainly driven by major hub cities whose centralities had been strengthened with more route connections. Since China's air passenger traffic had quickly restored in the second half of 2020, we argue that the changes in the CSFN during COVID-19 were unlikely to be a result of the substitution effect between freighter and passenger aircraft. It was more likely a result of the higher air cargo demand during the pandemic and airlines' realisation of the importance of freighter operations in China.

20.
Sci Total Environ ; 824: 153687, 2022 Jun 10.
Article in English | MEDLINE | ID: covidwho-1665459

ABSTRACT

Wastewater surveillance is a promising tool for population-level monitoring of the spread of infectious diseases, such as the coronavirus disease 2019 (COVID-19). Different from clinical specimens, viruses in community-scale wastewater samples need to be concentrated before detection because viral RNA is highly diluted. The present study evaluated eleven different virus concentration methods for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in wastewater. First, eight concentration methods of different principles were compared using spiked wastewater at a starting volume of 30 mL. Ultracentrifugation was the most effective method with a viral recovery efficiency of 25 ± 6%. The second-best option, AlCl3 precipitation method, yielded a lower recovery efficiency, only approximately half that of the ultracentrifugation method. Second, the potential of increasing method sensitivity was explored using three concentration methods starting with a larger volume of 1000 mL. Although ultracentrifugation using a large volume outperformed the other two large-volume methods, it only yielded a comparable method sensitivity as the ultracentrifugation using a small volume (30 mL). Thus, ultracentrifugation using less volume of wastewater is more preferable considering the sample processing throughput. Third, a comparison of two viral RNA extraction methods showed that the lysis-buffer-based extraction method resulted in higher viral recovery efficiencies, with cycle threshold (Ct) values 0.9-4.2 lower than those obtained for the acid-guanidinium-phenol-based method using spiked samples. These results were further confirmed by using positive wastewater samples concentrated by ultracentrifugation and extracted separately by the two viral RNA extraction methods. In summary, concentration using ultracentrifugation followed by the lysis buffer-based extraction method enables sensitive and robust detection of SARS-CoV-2 for wastewater surveillance.


Subject(s)
COVID-19 , Viruses , Humans , RNA, Viral , SARS-CoV-2 , Viruses/genetics , Wastewater , Wastewater-Based Epidemiological Monitoring
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