Guidelines in Wastewater-based Epidemiology of SARS-CoV-2 with Diagnosis (preprint)

With the global spread and increasing transmission rate of SARS-CoV-2, more and more laboratories and researchers are turning their attention to wastewater-based epidemiology (WBE), hoping it can become an effective tool for large-scale testing and provide more ac-curate predictions of the number of infected individuals. Based on the cases of sewage sampling and testing in some regions such as Hong Kong, Brazil, and the United States, the feasibility of detecting the novel coronavirus in sewage is extremely high. This study re-views domestic and international achievements in detecting SARS-CoV-2 through WBE and summarizes four aspects of COVID-19, including sampling methods, virus decay rate cal-culation, standardized population coverage of the watershed, algorithm prediction, and provides ideas for combining field modeling with epidemic prevention and control. Moreover, we highlighted some diagnostic techniques for detection of the virus from sew-age sample. Our review is a new approach in identification of the research gaps in waste water-based epidemiology and diagnosis and we also predict the future prospect of our analysis.

"To honour cleanness and shame filth”: medical facemasks as the narrative of nationalism and modernity in China

As the Covid-19 pandemic has swept across the world, the wearing of medical facemasks has become a hot topic on social media. In China, the relevant discourses are entangled with codes of medical science, national self-esteem and appropriated modernity. These discourses can be dated back to the narrative established by Dr Wu Lien-teh, the great fighter in the Manchurian plagues of 1910–1911 and 1920–1921. This paper reveals that Wu and his colleagues used different strategies when displaying to the Western world their achievements in the anti-plague battle and when proving the effectiveness of the Western medical and hygienic system to Chinese people. Wu and his colleagues used metonymies, analogues and metaphors on or related to medical facemasks to illustrate the possibility of building a modernised nation with sovereignty. Because the construction of a sanitary system in China has always been labelled as a patriotic movement (Rogaski, Ruth. 2004. Hygienic Modernity: Meanings of Health and Disease in Treaty-Port China. Berkeley: University of California Press, 285–298), the wearing of medical facemasks has constituted an important part of the narrative of nationalism and hygienic modernity. This discourse continues to play a significant role in today's campaign against the coronavirus.

Key mutations in the spike protein of SARS-CoV-2 affecting neutralization resistance and viral internalization.

To control the ongoing COVID-19 pandemic, a variety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been developed. However, the rapid mutations of SARS-CoV-2 spike (S) protein may reduce the protective efficacy of the existing vaccines which is mainly determined by the level of neutralizing antibodies targeting S. In this study, we screened prevalent S mutations and constructed 124 pseudotyped lentiviral particles carrying these mutants. We challenged these pseudoviruses with sera vaccinated by Sinovac CoronaVac and ZF2001 vaccines, two popular vaccines designed for the initial strain of SARS-CoV-2, and then systematically assessed the susceptivity of these SARS-CoV-2 variants to the immune sera of vaccines. As a result, 14 S mutants (H146Y, V320I + S477N, V382L, K444R, L455F + S477N, L452M + F486L, F486L, Y508H, P521R, A626S, S477N + S698L, A701V, S477N + T778I, E1144Q) were found to be significantly resistant to neutralization, indicating reduced protective efficacy of the vaccines against these SARS-CoV-2 variants. In addition, F486L and Y508H significantly enhanced the utilization of human angiotensin-converting enzyme 2, suggesting a potentially elevated infectivity of these two mutants. In conclusion, our results show that some prevalent S mutations of SARS-CoV-2 reduced the protective efficacy of current vaccines and enhance the infectivity of the virus, indicating the necessity of vaccine renewal and providing direction for the development of new vaccines.

Reciprocal Effect between Depressive Symptoms and Adolescent Non-suicidal self-injury before and after COVID-19: A Longitudinal Study (preprint)

Background Non-suicidal   self-injury (NSSI) is a common psychological and behavioral problem among   adolescents and has now become a major public health problem for adolescents.   Since the COVID-19 outbreak in 2019, it has caused various mental health   problems, such as anxiety, depression, and mental burnout, contributing to a   severe mental health crisis globally. Thus far, a few studies recorded the   temporal change in adolescents’ psychological status during the COVID-19   pandemic as well as that with the implementation of large-scale public health   intervention methods, and this study adds to the evidence. Methods Based on   the Chengdu Positive Child Development (CPCD) survey, the baseline dataset   was collected in December 2019, and the first follow-up of the CPCD was conducted   in July 2020. A total of 6,023 adolescents aged 10-19 were recruited from   five primary and middle schools. Two independent autoregressive cross-lagged   models were used to test the bidirectional relationship between NSSI and   depressive symptoms in adolescents; logistic regression analysis was used to   explore the predictors of NSSI implementation in adolescents with depressive   symptoms, which could provide an entry point for behavioral interventions to   NSSI. Results The   prevalence of depressive symptoms among our participants was 32.69% at   baseline, and 34.27% at follow-up. The occurrence rate of NSSI in adolescents   who may have depressive symptoms was 44.34%%, and that during the pandemic   was 53.44%. The difference was statistically significant (P <   0.05). The results of the binary logistic analysis showed that among   adolescents, gender, duration of the online class, depression mood, place of   residence, and self-perception of relationship with caregivers were the risk   factors for NSSI (or > 1, β> 0), and daily sleep hours positive mood   was the protective factor (or < 1, β< 0).  The lag effect of adolescent depression on   their NSSI behavior is significant, which means that based on controlling the   adolescent baseline NSSI, the deeper the adolescent depression degree, the   more frequent their NSSI behavior (β=0.26, P<0.01). At the same time,   adolescents' NSSI behavior also had a lagging effect on depressive symptoms,   and adolescents with self-injury behavior were more likely to be depressed (β=0.02, P<0.01). Depression and   NSSI are mutual(β=0.77,   P<0.05；β=0.27,   P<0.01). Conclusions The   increased depressive symptoms among adolescents exacerbated their NSSI   behaviors and hurt their mental health during COVID-19. Screening for   depression should be carried out early to serve as a warning sign in   preventing and reducing NSSI in adolescents.

Differential Psychological Factors Associated With Unnecessary Dental Avoidance and Attendance Behavior During the Early COVID-19 Epidemic.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 is challenging the dental community to an unprecedented degree. Knowledge of the increased risk of infection in dental settings has been disseminated to the public and guidelines have been formulated to assist dental attendance decision-making. However, dental attendance behaviors incompatible with treatment need is not uncommon in clinical settings. Important gaps remain in the knowledge about how psychological factors are affecting dental attendance behaviors during the COVID-19 epidemic. In this cross-sectional study, a questionnaire survey was performed during February and March 2020. A total of 342 and 294 dental patients who attended and avoided dental visits, respectively, were included. The participants were classified into four groups based on dental attendance behavior and emergent/urgent dental treatment need. Bivariate analysis was performed to investigate factors associated with dental attendance. Multivariable logistic regression based on principal component scores was performed to identify major psychological constructs associated with unnecessary dental avoidance and attendance. Among all the factors explored, inability to wear masks during dental treatment (P < 0.001; effect size: 0.32) was most closely associated with the overall pattern of dental attendance among participants. Multivariable regression suggested that unnecessary dental avoidance was associated with perceived risk of infection in general and in dental settings (odds ratio [95% CI]: 0.62 [0.53, 0.72]; p < 0.001), perceived impact of COVID-19 and dental problems on general health (0.79 [0.65, 0.97]; 0.021), and personal traits such as trust and anxiety (0.77 [0.61, 0.98]; 0.038). Unnecessary dental attendance was associated with optimism toward the epidemic (1.68 [1.42, 2.01]; <0.001) and trust (1.39 [1.13, 1.74]; 0.002). Multidisciplinary efforts involving dental and medical professionals as well as psychologists are warranted to promote more widespread adoption, among the general public, of dental attendance behaviors compatible with dental treatment need during the COVID-19 epidemic.

Reopening International Borders without Quarantine: Contact Tracing Integrated Policy against COVID-19 (preprint)

With the COVID-19 vaccination widely implemented in most countries, propelled by the need to revive the tourism economy, there is a growing prospect for relieving the social distancing regulation and reopening borders in tourism-oriented countries and regions. The need incentivizes stakeholders to develop border control strategies that fully evaluate health risks if mandatory quarantines are lifted. In this study, we have employed a computational approach to investigate the contact tracing integrated policy in different border reopening scenarios in Hong Kong, China. Built on a modified SEIR epidemic model with a 30% vaccination coverage, the results suggest that scenarios with digital contact tracing and quick isolation intervention can reduce the infectious population by 92.11% compared to those without contact tracing. By further restricting the inbound population with a 10,000 daily quota and applying moderate-to-strong community non-pharmacological interventions (NPIs), the average daily confirmed cases in the forecast period of 60 days can be well controlled at around 9 per day (95% CI: 7-12). Two main policy recommendations are drawn from the study. First, digital contact tracing would be an effective countermeasure for reducing local virus spread, especially when it is applied along with a moderate level of vaccination coverage. Second, implementing a daily quota on inbound travelers and restrictive community NPIs would further keep the local infection under control. This study offers scientific evidence and prospective guidance for developing and instituting plans to lift mandatory border control policies in preparing for the global economic recovery.

Remediation of organophosphorus pesticide polluted soil using persulfate oxidation activated by microwave

Contaminated sites from pesticide industry have attracted global concern due to the characteristics of organic pollution with high concentrations and complete loss of habitat conditions. Remediation of organophosphorus pesticide polluted soil using microwave-activated persulfate (MW/PS) oxidation was investigated in this study, with parathion as the representative pesticide. Approximately 90 % of parathion was degraded after 90 min of MW/PS oxidation treatment, which was superior to those by single PS or MW treatment. Relatively greater performances for parathion degradation were obtained in a relatively larger PS dosage, higher microwave temperature, and lower organic matter content. Appropriate soil moisture favored parathion degradation in soil. SO4-, OH, O2-, and 1O2 generated in the MW/PS system all contributed to parathion degradation. Multiple spectroscopy analyses indicated that PO and PS bonds in parathion were destroyed after MW/PS oxidation, accompanied by generation of hydroxylated and carbonylated byproducts. The soil safety after parathion degradation was assessed via model prediction. Furthermore, MW/PS oxidation also exhibited great performance for degradation of other organophosphorus pesticides, including ethion, phorate, and terbufos.

Case Report: Opportunities for Treatment of Severe COVID-19 Patients-Lessons From a Death Case.

With the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the incidence of coronavirus disease (COVID-19) increases each day. To date, there is no specific anti-SARS-CoV-2 drug. The usual approach to treating COVID-19 is treating its symptoms. However, this approach is limited by the different conditions of each area. We treated a 57-year-old man who was initially diagnosed with a severe type of the infection, but he progressed to a critical condition and eventually died. We learned valuable lessons from this case. The first lesson is the need to use immediate invasive mechanical ventilation if there is no obvious improvement after using non-invasive ventilation for several hours, which directly affects the prognosis. Another lesson is the risk involved in transferring severe COVID-19 patients. In the process of transfer, various threats may be encountered at any time. Thus, accurate assessment of the patient's condition and strict medical conditions are highly required. During the patient's 25-day treatment, we performed cardiopulmonary resuscitation twice. Currently, many patients require invasive mechanical ventilation and transfer to a superior hospital. We hope our findings will provide some advice and help for treating severe and critical COVID-19 cases.

Epidemiological and Clinical Characteristics of COVID-19 Patients with Cancers: A Systematic Review and Meta-Analysis of Global Data (preprint)

Background Data on the prevalence of cancer in coronavirus disease 2019 (COVID-19)-infected patients and the severe illness incidence and mortality of COVID-19 patients with cancers remains unclear. Methods We systematically searched PubMed, Embase, Cochrane Library, and Web of Science, from database inception to July 15, 2020, for studies of patients with COVID-19 infection that had available comorbidity information on cancer. The primary endpoint was the pooled prevalence of cancer in COVID-19 patients and the secondary endpoint was the outcomes of COVID-19-infected cancer patients with incidence of severe illness and death rate. We calculated the pooled prevalence and corresponding 95% confidence intervals (95% CIs) using a random-effects model, and performed meta-regression analyses to explore heterogeneity. Subgroup analyses were conducted based on continent, country, age, sample size and study design. Findings A total of 107 eligible global studies were included in the systematic review. 90 studies with 94,845 COVID-19 patients in which 4,106 patients with cancer morbidity were included in the meta-analysis for prevalence of cancer morbidity among COVID-19 patients. 21 studies with 70,969 COVID-19 patients in which 3,351 patients with cancer morbidity who had severe illness or death during the studies. The overall prevalence of cancer among the COVID-19 patients was 0.07 (95% CI 0.05~0.09). The cancer prevalence in COVID-19 patients of Europe (0.22, 95% CI 0.17~0.28) was higher than that in Asia Pacific (0.04, 95% CI 0.03~0.06) and North America (0.05, 95% CI 0.04~0.06). The prevalence of COVID-19-infected cancer patients over 60 years old was 0.10 (95% CI 0.07~0.14), higher than that of patients equal and less than 60 years old (0.05, 95% CI 0.03~0.06). The pooled prevalence of severe illness among COVID-19 patients with cancers was 0.35 (95% CI 0.27~0.43) and the pooled death rate of COVID-19 patients with cancers was 0.18 (95% CI 0.14~0.18). The pooled incidence of severe illness of COVID-19 patients with cancers from Asia Pacific, Europe, and North America were 0.38(0.24, 0.52), 0.36(0.17, 0.55), and 0.26(0.20, 0.31), respectively; and the pooled death rate from Asia Pacific, Europe, and North America were 0.17(0.10, 0.24), 0.26(0.13, 0.39), and 0.19(0.13, 0.25), respectively. Interpretation To our knowledge, this study is the most comprehensive and up-to-date meta-analysis assessing the prevalence of cancer among COVID-19 patients, severe illness incidence and mortality rate. The prevalence of cancer varied significantly in geographical continents and ages. The COVID-19 patients with cancer were at-risk for severe illness and a high death rate. The European COVID-19 patients had the highest cancer prevalence among the three continents examined and were also the most likely to progress to severe illness and death. Although the Asia Pacific COVID-19 patients had the lowest cancer prevalence, their severe illness rate was similar to that of European.

Forecasting COVID-19 onset risk and evaluating spatiotemporal variations of the lockdown effect in China (preprint)

 It is important to forecast the risk of COVID-19 symptom onset and thereby evaluate how effectively the city lockdown measure could reduce this risk. This study is a first comprehensive, high-resolution investigation of spatiotemporal heterogeneities in the effect of the Wuhan lockdown on the risk of COVID-19 symptom onset in all 347 Chinese cities. An extended Weight Kernel Density Estimation model was developed to predict the COVID-19 onset risk under two scenarios (i.e., with and without Wuhan lockdown). The Wuhan lockdown, compared with the scenario without lockdown implementation, delayed the arrival of the COVID-19 onset risk peak for 1-2 days in general and lowered risk peak values among all cities. The decrease of the onset risk attributed to the lockdown was more than 8% in over 40% of Chinese cities, and up to 21.3% in some cities. Lockdown was the most effective in areas with medium risk before lockdown.

Transportation, Germs, Culture: A Dynamic Graph Model of 2019-nCoV Spread (preprint)

Since the outbreak of 2019 novel coronavirus (2019-nCoV) at the hardest-hit city of Wuhan, the fast-moving spread has killed over three hundred people and infected more than ten thousands in China1. There are more than one hundred cases outside of China, affecting a dozen of countries globally2. The genome sequence of 2019-nCoV has been reported and fast diagnostic kits, effective treatment as well as preventive vaccines are rapidly being developed3. Initial fast-growing confirmed cases triggered lock-down of Wuhan as well as nearby cities in Hubei Province. Mathematical models have been proposed by scientists around the world to project the numbers of infected cases in the coming days 4,5. However, major factors such as transportation and cultural customs have not been weighed enough. Our model is not set out for precise prediction of the number of infected cases, rather, it is meant for a glance of the dynamics under a public epidemic emergency situation and of different contributing factors. We hope that our model and simulation would provide more insights and perspective information to public health authorities around the globe for better informed prevention and containment solution.