Development and application of N-protein blocking ELISA for detecting porcine epidemic diarrhea virus antibodies

The purpose of this study is to establish a blocking ELISA antibodies detection method for porcine epidemic diarrhea virus (PEDV). The purified N protein was used as the coating antigen, and the ELISA reaction conditions were optimized by the chess rboard titration. A blocking ELISA method for detecting PEDV antibodies was established, and its specificity, sensitivity and repeatability tests were carried out. One hundred and forty clinical serum samples were tested, and the results were compared with commercially IDvet PEDV indirect ELISA antibodies detection kit. The results showed that the best antigen coating concentration was 625 ng.mL-1, and the best dilution ratio of serum was 1:1;The best dilution of the HRP-conjugated antibody working solution was 1:5 000;There was no cross-reaction with healthy pig serum and the positive sera of common pig disease pathogens, such as classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), and transmissible gastroenteritis virus (TGEV). The sensitivity of PEDV positive serum was 1:16, which was equivalent to that of IDvet ELISA kit (titer 1:32). The coefficient of variation of within-run and between-run repeatability test is less than 10%, so it showed that the blocking ELISA established in this study had good repeatability and stability;the kappa value of detected 140 clinical porcine serum using this method was 0.87 when compared with IDvet ELISA. The above results indicated that the established blocking ELISA method for detecting PEDV antibodies in this study could be applied to the prevention and control of PEDV, epidemiological investigation and the monitoring of antibody levels after vaccine immunization.

Cough Recognition Based on Mel-Spectrogram and Convolutional Neural Network.

In daily life, there are a variety of complex sound sources. It is important to effectively detect certain sounds in some situations. With the outbreak of COVID-19, it is necessary to distinguish the sound of coughing, to estimate suspected patients in the population. In this paper, we propose a method for cough recognition based on a Mel-spectrogram and a Convolutional Neural Network called the Cough Recognition Network (CRN), which can effectively distinguish cough sounds.

Inhalation of Heliox as a potential treatment for the ARDS caused by COVID-19 (preprint)

Corona virus disease 2019 (COVID-19) is currently a global pandemic It presents as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) due to COVID-19 infection. Despite the widespread use of symptomatic, antiviral, , and supportive treatment, the daily death toll from COVID-19 is still rising. The most common lethal complication is acute respiratory distress syndrome (ARDS). Mechanical ventilation is one of the necessary support methods of treating ARDS. Heliox (Helium-oxygen mixture) inhalation can reduce respiratory work of breathing, improve oxygenation, improve lung compliance, and effectively optimize the treatment of ARDS. Heliox also has potential anti-inflammatory, neuroprotective, and cardiac effects, and could reduce the inflammatory storm caused by SARS-CoV-2. This article reviews the properties of heliox, the therapeutic mechanism for ARDS, and the effects of heliox on inflammation, nerves, and the heart. Conclusion We suggests that heliox is a potential treatment for COVID-19.

Comparison of acute pneumonia caused by SARS-COV-2 and other respiratory viruses in children: a retrospective multi-center cohort study during COVID-19 outbreak (preprint)

Background: Until July 14, 2020, coronavirus disease-2019 (COVID-19) has infected more than 130 million individuals and has caused a certain degree of panic. Viral pneumonia caused by common viruses such as respiratory syncytial virus, rhinovirus, human metapneumovirus, human bocavirus, and parainfluenza viruses have been more common in children. However, the incidence of COVID-19 in children was significantly lower than that in adults. The purpose of this study was to describe the clinical manifestations, treatment and outcomes of COVID-19 in children compared to those of other sources of viral pneumonia diagnosed during the COVID-19 outbreak. Methods: Children with COVID-19 and viral pneumonia admitted to 20 hospitals were enrolled in this retrospective multi-center cohort study. A total of 64 children with COVID-19 were defined as the COVID-19 cohort, of which 40 children who developed pneumonia were defined as the COVID-19 pneumonia cohort. Another 284 children with pneumonia caused by other viruses were defined as the viral pneumonia cohort. Results: Compared to the viral pneumonia cohort, children in the COVID-19 cohort were mostly exposed to family members confirmed to have COVID-19 (53/64 vs. 23/284), were of older median age (6.3 vs. 3.2 years), and had a higher proportion of ground-glass opacity (GGO) on computed tomography (18/40 vs. 0/38) (all P ＜0.001). Children in the COVID-19 pneumonia cohort had a lower proportion of severe cases (1/40 vs. 38/284, P =0.048), and lower cases with high fever (3/40 vs 167/284, P ＜0.001), requiring intensive care (1/40 vs 32/284, P ＜0.047) and with shorter symptomatic duration (median 5 vs 8 days, P ＜0.001). The proportion of cases with evaluated inflammatory indicators, biochemical indicators related to organ or tissue damage, D-dimer and secondary bacterial infection were lower in the COVID-19 pneumonia cohort than in the viral pneumonia cohort (all P ＜0.05). No statistical differences were found in the duration of positive PCR results from pharyngeal swabs in 25 children with COVID-19 who received antiviral drugs (lopinavir-ritonavir, ribavirin, and arbidol) as compared to duration in 39 children without antiviral therapy [median 10 vs. 9 days, P =0.885]. Conclusion: The symptoms and severity of COVID-19 pneumonia in children were no more severe than those in children with other viral pneumonias. Lopinavir-ritonavir, ribavirin and arbidol do not shorten the duration of positive PCR results from pharyngeal swabs in children with COVID-19. During the COVID-19 outbreak, attention also must be given to children with infection by other pathogens infection.

Mental Disorders of Healthcare Workers Fighting COVID-19: Little Relieved After One Month (preprint)

Background: More than 210,000 medical workers have fought against the Coronavirus Disease 2019 (COVID-19) in Hubei of China since December 2019. However, it was unknown if the mental health disorders for frontline medical staff was relieved one month later. Methods: Medical workers in Wuhan and other cities in Hubei Province was requested to fill out an online survey, which assessed their degrees of anxiety, insomnia, depression, and post-traumatic stress disorder (PTSD). Outcomes: A total of 1,091 respondents (32·63% male, 67·37% female) were valid for statistical analysis. The prevalence was anxiety (52·98% with male 50·84% and female 54·01%), insomnia (78·83% with male 78·09% and female 79·18%), depression (56·10% with male 55·34% and female 56·46%) and PTSD (11·09% with male 10·11% and female 11·56%). For educational attainment, those with doctoral and masters’ degrees (D/M) may suffer from more anxiety (median 7·0 [IQR 2·0-8·5] vs. median 5·0 [IQR 5·0-8·0], P =0·02) and PTSD (median 26·0 [IQR 19·5-33·0] vs. median 23·0 [IQR 19·0-31·0], P =0·04) than those with lower educational degrees. Interpretation: Mental disorders of healthcare workers were little relieved one month after they had ended fighting COVID-19, and potential mitigating factors and interventions is necessary.Funding Statement: The study was financially supported by the National Natural Science Foundation of China (8174356); the Open Project of Hubei Key Laboratory of Wudang Local Chinese Medicine Research (Hubei University of Medicine) (WDCM2018002); the Key Discipline Project of Hubei University of Medicine and the Foundation for Innovative Research Team of Hubei University of Medicine (2018YHKT01).Declaration of Interests: The authors declared no interest conflict in this study.Ethics Approval Statement: This study was approved by the Ethic Committee of Renmin Hospital of Hubei University of Medicine.

Clinical characteristics of neonates with coronavirus disease 2019 (COVID-19): a systematic review (preprint)

This study aimed to summarize the existing literature on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in newborns to clarify the clinical features and outcomes of neonates with COVID-19. A systematic search was performed in PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP databases from January 1, 2019 to April 30, 2020. The references of relevant studies were also searched. A descriptive summary was organized by aspects of clinical presentations (symptoms, laboratory examinations, and imaging) and outcomes. We identified 14 studies reporting 18 newborns with COVID-19. The most common clinical manifestations were fever (62.5%), shortness of breath (50.0%), diarrhea/vomiting/feeding intolerance(43.8%), cough (37.5%), dyspnea (25.0%), and nasal congestion/runny nose/sneeze(25.0%). Atypical symptoms included jaundice and convulsion. Lymphocyte numbers decreased in 5 cases, and radiographic findings were likely to show pneumonia. All newborns recovered and discharged from the hospital, and there was no death.Conclusion: Clinical symptoms of neonatal SARS-CoV-2 infection are atypical, most of them are mild. Up to now, the prognosis of newborns is good, and there is no death. Intrauterine vertical transmission is possible, but confirmed evidence is still lacking. The Long-term follow-up of potential influences of SARS-CoV-2 infection on neonates need further exploration.

The effects of chloroquine and hydroxychloroquine on ACE2 related coronavirus pathology and the cardiovascular system: An evidence based review

The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a serious threat to global public health and there is currently no effective antiviral therapy. It has been suggested that Chloroquine (CQ) and hydroxychloroquine (HCQ), which were primarily employed as prophylaxis and treatment for malaria, could be used to treat COVID-19. CQ and HCQ may be potential inhibitors of SARS-CoV-2 entry into host cells, which is mediated via the angiotensin-converting enzyme 2 (ACE2), and may also inhibit subsequent intracellular processes which lead to COVID-19, including damage to the cardiovascular system. However, paradoxically, CQ and HCQ have also been reported to cause damage to the cardiovascular system. In this review, we provide a critical examination of the published evidence. CQ and HCQ could potentially be useful drugs in the treatment of COVID-19 and other ACE2 involved virus infections, but the antiviral effects of CQ and HCQ need to be tested in more well-designed clinical randomized studies and their actions on the cardiovascular system need to be further elucidated. However, even if it were to turn out that CQ and HCQ are not useful drugs in practice, further studies of their mechanism of action could be helpful in improving our understanding of COVID-19 pathology.

A systematic review and meta-analysis of the efficacy of medical masks and N95 respirators for protection against respiratory infectious diseases, including COVID-19 in medical staff (preprint)

To evaluate the efficacy of N95 respirators and medical masks for protection against respiratory infectious diseases, including COVID-19. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies evaluating the use of N95 respirators and medical masks for protection against respiratory infectious diseases. We retrieved relevant articles published from January 1994 to January 2020 by searching the PubMed, EMBASE, Cochrane CENTRAL, and Web of Science databases. The study quality was evaluated using the Cochrane Risk of Bias tool with RevMan 5.3 software. Eleven RCTs adjusted for clustering were included in the meta-analysis. Compared with the control group, N95 respirators or medical masks conferred significant protection against respiratory infectious diseases (odds ratio (OR) = 0.50; 95% CI: 0.29–0.84). Compared to medical masks, N95 respirators conferred significant protection against respiratory infectious diseases (OR = 0.75; 95% confidence interval (CI): 0.57–0.99). Meta-analysis of 10 observational studies adjusting for clustering also suggested that N95 respirators and medical masks are effective for protection against respiratory infectious diseases (OR = 0.59; 95% CI: 0.42–0.82). However, only one case report showed the effectiveness of medical masks for preventing COVID-19. Although medical masks and N95 respirators may confer significant protection against respiratory infectious diseases, there is insufficient evidence to conclude that these types of personal protective equipment offer similar protection against COVID-19. Therefore, in the absence of sufficient resources during an epidemic, medical masks and N95 respirators should be reserved for high-risk, aerosol-generating producing procedures.

Children with COVID-19 behaving milder may challenge the public policies: A Systematic Review and Meta-Analysis (preprint)

Background: The emerging virus is rampaging globally. Great efforts are needed to cut down the transmission. Clinical characteristics of infected children have been described previously. No meta-analysis on this subgroup have been published.Methods: A single-arm meta-analysis was conducted. We searched PubMed, Google Scholar, Web of Science, three preprints websites and other Chinese database for studies presenting characteristics of children confirmed with Coronavirus Disease 2019 (COVID-19) from December 1 2019 to March 28 2020. Quality Appraisal of Case Series Studies Checklist was used to assess quality and publication bias was analyzed by Egger’s test. Random-effect model was used to calculate the pooled incidence rate (IR) or mean difference (MD) with 95% confidence intervals (CI), or a fixed model instead when I2<50%. We conducted subgroup analysis according to geographic region. Additionally, we searched United Nations Educational Scientific and Cultural Organization to see how different countries act to the education disruption in COVID-19.Results: 14 studies (two unpublished) with 361 pediatric patients were included. The mean age was 5.5 (95% CI: 0.344–0.765) years old. 23.4% of children were asymptomatic (95%CI: 0.112-0.377). 32.3% (95%CI: 0.163-0.503) showed normal computed tomography imaging, besides, four children were admitted in intensive care units (0, 95%CI: 0.000-0.001) and one death was reported (0, 95%CI: 0.000-0.001). Up to 191 countries have implemented nationwide school closures, affecting over 91% of the world’s students.Conclusion: Children were also susceptible to SARS-CoV-2, while critical cases or death were rare. Characterized by mild presentation, the dilemma that children may become a potential spreader in the pandemic, while strict managements like prolonged school closures, may undermine their well-beings. Thus, the public policies are facing challenge. 

Development of high affinity monobodies recognizing SARS-CoV-2 antigen (preprint)

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a threat to global public health. Prompt patient identification and quarantine is the most effective way to control its rapid transmission, which can be facilitated by early detection of viral antigens. Here we present a platform to develop and optimize the fibronectin-based affinity-enhanced antibody mimetics (monobodies) for recognizing viral antigens. Specifically, we developed monobodies targeting SARS-CoV-2 nucleocapsid (N) protein. We showed that two monobodies, NN2 and NC2, bind to N protein’s N- and C-terminal domains respectively with a Kd in nM range.The specificity of the recognition was confirmed with co-immunoprecipitation and immunofluorescence assays. Furthermore, we demonstrated that one round of in vitro maturation using mRNA display can improve the binding affinity of monobodies. Machine learning algorithms were integrated with deep sequencing data for selecting candidates that improve the detection sensitivity of N. Using this pair of monobodies, we have developed an enzyme-linked immunosorbent assay (ELISA) for viral detection. We were able to detect recombinant N at 4 pg/ml and detect N in viral culture supernatant, with no cross-reactivity with other CoV. Integrating high-dense mutagenesis, mRNA display, deep sequencing and machine learning, this platform can be applied through iterations to identify and optimize monobodies against emerging viral antigens, potentiating point-of-care detection of communicable diseases in a cost-and time-sensitive manner.Authors Yushen Du, Tian-hao Zhang, Xiangzhi Meng, Yuan Shi, and Menglong Hu contributed equally to this work.

Characteristics of online medical care consultation for pregnant women during the COVID-19 outbreak: a cross-sectional study (preprint)

Background During the Coronavirus Disease 2019 (COVID-19) outbreak, emergency traffic bans limited accessibility of some medical resource for pregnant women. Fear of viral transmission also prevented pregnant women from seeking routine antenatal care (ANC). This study described the needs of pregnant women and the contents of online obstetric consultation in representative areas with various severity of the epidemic in China. Methods From February 10 th to 23 rd , we collected data on online obstetric consultations and women’s satisfaction in mild, moderate and severe epidemic areas through an e-health provider’s platform. Information on women’s needs, contents of the consultation and satisfaction were collected and compared by epidemic areas. Results A total of 2599 pregnant women participated in this study, of whom 448, 1322 and 819 women were from the mild, moderate and severe epidemic areas, respectively. The distributions of the amount of online consultation were significantly different not only in different areas, but also in different trimesters. The more severe the epidemic was and the more advanced the pregnancy was, the higher the amount of second category (changed their schedules of ANC and/or delivery as well as method of delivery) was. 957 participants completed a satisfaction survey. For most of the participants, it’s their first time to use the e-health, and nearly 90% participants were completely or mostly satisfied with the online consultation. Conclusions Our study found that during the outbreak, many pregnant women had changed their scheduled ANC visits without authorization, and the more serious the epidemic was, the more common it occurred. The needs for online consultation was substantial. In order to prevent irreversible obstetric adverse events, an appropriate ANC contingency plan with e-health services is highly recommended during the Public Health Emergency of International Concern (PHEIC).

Summary of consensus documents: prevention and control of the 2019 novel conoravirus infection in newborn infants * / 重庆医学

Since the end of 2019, an outbreak of pneumonia caused by a novel coronavirus named 2019 novel coronavirus (2019-nCoV) has occurred in in China. The dramatically rapid spread and strong infectivity of this virus has attracted global attention. Neonates are thought to be susceptible to the virus, because their immune system is not well developed. Neonates have been reported to be affected by this virus. The Chinese Medical Association, Chinese Medical Doctor Association, Pediatric Professional Committee of the Chinese People's Liberation Army have put forward strategies for the effective prevention and control of the 2019-nCoV infection in neonates. This expert review summarized the key points of the above three prevention and control consensus and programs.

Guidance on strengthening the management processes of children′s fever in outpatient department during the novel coronavirus pneumonia epidemic period (First Edition) / 中华实用儿科临床杂志

Novel Coronavirus Pneumonia (NCP) is a class B infectious disease, which is prevented and controlled according to class A infectious diseases. Recently, children′s NCP cases have gradually increased, and children′s fever outpatient department has become the first strategic pass to stop the epidemic. Strengthening the management of the fever diagnosis process is very important for early detection of suspected children, early isolation, early treatment and prevention of cross-infection. This article proposes prevention and control strategies for fever diagnosis, optimizes processes, prevents cross-infection, health protection and disinfection of medical staff, based on the relevant diagnosis, treatment, prevention and control programs of the National Health and Health Commission and on the diagnosis and treatment experience of experts in various provinces and cities. The present guidance summarizes current strategies on pre-diagnosis; triage, diagnosis, treatment, and prevention of 2019-nCoV infection in common fever, suspected and confirmed children, which provide practical suggestions on strengthening the management processes of children′s fever in outpatient department during the novel coronavirus pneumonia epidemic period.