Design and Synthesis of Novel Factor XIa Inhibitors with Bicyclic Isoquinoline and Naphthalene Fragments (preprint)

FXIa has emerged as a promising therapeutic target for treating thrombotic diseases. With the aim to replace the aniline motif of asundexian with novel P2’ fragments, bicyclic isoquinoline and naphthalene rings were designed. The target compounds with isoquinoline ring were synthesized via 13 steps of chemical reactions. Substituents within the rings were investigated to elucidate the structural determinants governing selective or dual inhibition of FXIa and Plasma Kallikrein (PKa). In vitro testing showed that some of designed compounds exhibited comparable potency against both FXIa and PKa, while others achieved up to 94-fold selectivity. Analysis of structure-activity relationships (SARs) uncovered the pivotal role of the carboxylic acid moiety in retaining inhibition of FXIa and PKa, and the steric hindrance and hydrogen-bond receptor functional groups were identified as key factors influencing the selectivity of FXIa inhibition over PKa. The docking study additionally unveiled different binding modes that play a significant role in the observed activity and selectivity. Furthermore, the selected compounds significantly extended the plasma coagulation time in a dose-dependent manner. Altogether, the bicyclic compounds may be promising lead compounds for the development of highly effective FXIa inhibitors.

The determinants of virtual reality adoption for marine conservation

Initiatives for marine conservation are funded by revenue from marine sites. However, the emergence of COVID-19 has restricted travelling, thus leading to decreased revenue and weakening conservation efforts. Virtual reality technology to support marine conservation efforts is explored as it allows users to experience marine sites, without having to be there physically. This study examines factors influencing users' desire to adopt virtual reality technology in marine ecotourism. With the integration of Stimulus-Organism-Response framework and three behavioural theories (i.e. health belief model, attitude, and eTrust), a hypothetical model was constructed to investigate consumers’ intention to adopt virtual reality technology in marine ecotourism amidst the pandemic. The data were analysed and interpreted using structural equation modelling after 451 survey responses were obtained via an online questionnaire. Outcome expectation, perceived susceptibility, perceived severity, self-efficacy, and cues to action exhibit significant positive effects on attitude towards virtual reality technology in marine ecotourism. Consequently, attitude has a direct and indirect influence on use intention via eTrust. Post hoc analysis revealed that self-efficacy has a direct impact on eTrust and use intention. Total effect analysis further concluded that attitude has the greatest influence on use intention of virtual reality technology in marine ecotourism. This research contributes to the existing literature by utilizing health belief factors to explain use intention of technology towards marine conservation efforts. Recommendations including policy formulation and marketing initiatives were generated for marine ecotourism operators and policymakers.

Decrease in RT-PCR Ct values among SARS-CoV-2 positive samples during the emergence of the B.1.617.2 (Delta) variant in Malaysia (preprint)

The RT-PCR cycle threshold (Ct) value for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is inversely proportionate to the virus load in the patient’s specimen. These values could be beneficial to be used in monitoring the epidemic trajectory at the population level. The SARS-CoV-2 B.1.617.2 (Delta) variant which emerged in late 2020, caused an unprecedented exponential increase in SARS-CoV-2 infection cases worldwide. In Malaysia, the surge in coronavirus disease 2019 (COVID-19) cases and the inclining positivity rate contributed to the epidemic waves started in late May 2021. The sudden surge in cases was speculated to be associated with increased transmission caused by the emergence of the B.1.617.2 variant. This could be reflected by changes in the mean Ct value distribution which reflects the viral load in the population. In the present study, the Ct value distribution of COVID-19 infected person samples from the years 2020 and 2021 were tabulated against the SARS-CoV-2 genomic variants determined from genomic sequencing. A significant decreasing pattern of the mean Ct values from the overall 2020 and 2021 samples were noted (p<0.01). There was, however, high variability in the Ct values of samples obtained between 2020 and 2021 in contrast to samples with lower mean Ct value obtained in 2021.  The percentages representation of SARS-CoV-2 genomic variants B.1.36 and B.1.524 were 31.6% and 68.4%, respectively, for samples obtained in October and December 2020. Whereas samples obtained in June and July 2021 were 100% of the B.1.617.2 variant. The decreasing trend in the Ct value distribution from samples tested in our laboratory correlated well with the increasing weekly COVID-19 cases reported by the Malaysia national data which was subsequently attributed by the emergence of B.1.617.2 in the country. This study suggests that the Ct value distribution of samples taken from the screening of SARS-CoV-2 infected population could provide insight into the potential epidemiologic transmission dynamic at the population level and when coupled to the virus genomic sequencing surveillance could allow detection of an emerging SARS-CoV-2 variant with different transmission behaviour. This could facilitate early response control strategies to limit the transmission of an emerging SARS-CoV-2 variant.

Immune and pathophysiologic profiling of antenatal COVID-19 in the GIFT cohort: A Singaporean case-control study. (preprint)

Background COVID-19 has been a major public health threat for the past two years, with disproportionate effects on the elderly, immunocompromised, and pregnant women. While much has been done in delineating immune dysfunctions and pathogenesis in the former two groups, less is known about the disease's progression in expectant women and children born to them. To address this knowledge gap, we profiled the immune responses in maternal and child sera as well as breast milk in terms of antibody and cytokine expression and performed histopathological studies on placentae obtained from mothers convalescent from antenatal COVID-19. Methods and findings A total of 17 mother-child dyads (8 cases of antenatal COVID-19 and 9 healthy unrelated controls; 34 individuals in total) were recruited to the Gestational Immunity For Transfer (GIFT) study. Maternal and infant sera, and breast milk samples were collected over the first year of life. All samples were analyzed for IgG and IgA against whole SARS-CoV-2 spike protein, the spike receptor-binding domain (RBD), and previously reported immunodominant epitopes, with conventional ELISA approaches. Cytokine levels were quantified in maternal sera using multiplex microbead-based Luminex arrays. The placentae were examined microscopically. We found high levels of virus-specific IgG in convalescent mothers and similarly elevated titers in newborn children. Virus-specific IgG in infant circulation waned within 3-6 months of life. Virus-specific IgA levels were variable among convalescent individuals' sera and breast milk. Convalescent mothers also showed a blood cytokine signature indicative of a persistent pro-inflammatory state. Four placentae presented signs of acute inflammation marked by neutrophil infiltration even though >50 days had elapsed between virus clearance and delivery. Administration of a single dose of BNT162b2 mRNA vaccine to mothers convalescent from antenatal COVID-19 increased virus-specific IgG and IgA titers in breast milk. Conclusions Antenatal SARS-CoV-2 infection led to high plasma titres of virus-specific antibodies in infants postnatally. However, this was not reflected in milk; milk-borne antibody levels varied widely. Additionally, placentae from COVID-19 positive mothers exhibited signs of acute inflammation with neutrophilic involvement, particularly in the subchorionic region. Virus neutralisation by plasma was not uniformly achieved, and the presence of antibodies targeting known immunodominant epitopes did not assure neutralisation. Antibody transfer ratios and the decay of transplacentally transferred virus-specific antibodies in neonatal circulation resembled that for other pathogens. Convalescent mothers showed signs of chronic inflammation marked by persistently elevated IL17RA levels in their blood. A single dose of the Pfizer BNT162b2 mRNA vaccine provided significant boosts to milk-borne virus-specific antibodies, highlighting the importance of receiving the vaccine even after natural infection with the added benefit of enhanced passive immunity. The study is registered at clinicaltrials.gov under the identifier NCT04802278.

Electrochemical oxygen generator with 99.9% oxygen purity and high energy efficiency (preprint)

Under the growing crisis of coronavirus disease 2019 pandemic, the global medical system is facing the predicament of an acute shortage of medical-grade oxygen (O2, ≥ 99.5% purity). Herein, we manufactured an oxygen generation device relying on electrochemical technology. The performance of electrochemical oxygen generator (EOG) was remarkably improved to a practically applicable level, achieving long-term (>200 h), stable, and quick production (>1.5L/min) of high purity O2 (99.9%) under high energy efficiency (496 L/kW·h), viasimultaneous optimizations for intrinsic electrochemical reaction mechanism, electrocatalysts, and external cell structure. The EOG also presents powerful competitiveness in user experience, which finds expression in high portability (4.7 kg), nearly instant O2 production (<1 s), and a quiet working condition (<39 dB). The EOG shows great potential to substitute commercial pressure swing adsorption O2 generation devices, which may significantly impact the traditional oxygen production industry.  

Mathematical modeling of vaccination rollout and NPIs lifting on COVID-19 transmission with VOC: a case study in Toronto, Canada (preprint)

ABSTRACT Background Since December 2020, public health agencies have implemented a variety of vaccination strategies to curb the spread of SARS-CoV-2, along with pre-existing Nonpharmaceutical Interventions (NPIs). Initial strategy focused on vaccinating the elderly to prevent hospitalizations and deaths. With vaccines becoming available to the broader population, we aimed to determine the optimal strategy to enable the safe lifting of NPIs while avoiding virus resurgence. Methods We developed a compartmental deterministic SEIR model to simulate the lifting of NPIs under different vaccination rollout scenarios. Using case and vaccination data from Toronto, Canada between December 28, 2020 and May 19, 2021, we estimated transmission throughout past stages of NPI escalation/relaxation to compare the impact of lifting NPIs on different dates on cases, hospitalizations, and deaths, given varying degrees of vaccine coverages by 20-year age groups, accounting for waning immunity. Results We found that, once coverage among the elderly is high enough (80% with at least one dose), the main age groups to target are 20-39 and 40-59 years, whereby first-dose coverage of at least 70% by mid-June 2021 is needed to minimize the possibility of resurgence if NPIs are to be lifted in the summer. While a resurgence was observed for every scenario of NPI lifting, we also found that under an optimistic vaccination coverage (70% by mid-June, postponing reopening from August 2021 to September 2021can reduce case counts and severe outcomes by roughly 80% by December 31, 2021. Conclusions Our results suggest that focusing the vaccination strategy on the working-age population can curb the spread of SARS-CoV-2. However, even with high vaccination coverage in adults, lifting NPIs to pre-pandemic levels is not advisable since a resurgence is expected to occur, especially with earlier reopening.

Integrating PCR-free amplification and synergistic sensing for ultrasensitive and rapid CRISPR/Cas12a-based SARS-CoV-2 antigen detection (preprint)

Antigen detection provides particularly valuable information for medical diagnoses; however, the current detection methods are less sensitive and accurate than nucleic acid analysis. The combination of CRISPR/Cas12a and aptamers provides a new detection paradigm, but sensitive sensing and stable amplification in antigen detection remain challenging. Here, we present a PCR-free multiple trigger dsDNA tandem-based signal amplification strategy and a de novo designed dual aptamer synergistic sensing strategy. Integration of these two strategies endowed the CRISPR/Cas12a and aptamer-based method with ultra-sensitive, fast, and stable antigen detection. In a demonstration of this method, the limit of detection was at the single virus level (0.17 fM, approximately two copies/L) in SARS-CoV-2 antigen nucleocapsid protein analysis of saliva or serum samples. The entire procedure required only 20 minutes. Given our system's simplicity and modular setup, we believe that it could be adapted reasonably easily for general applications in CRISPR/Cas12a-aptamer-based detection.

Novel Coronavirus Pneumonia Epidemic Data Analysis and Regional Prevention and Control Research

At the beginning of 2020, a war without smoke of gunpowder came. Scientific prevention and accurate policy implementation is the key to epidemic prevention and control. General secretary Xi Jinping stressed the importance of using big data to strengthen the tracing and monitoring of the epidemic situation. With 1.6 billion mobile phone users in China, the use of Telecom big data analysis can provide strong decision support for epidemic prevention and control in a more real-time, accurate and comprehensive way. In the battle against novel coronavirus pneumonia, the Ministry of industry and information technology has been coordinating and organizing the information and communication industry to support the epidemic prevention and control work with the analysis of telecommunications big data.

Modeling the potential impact of indirect transmission on COVID-19 epidemic (preprint)

The spread of SARS-CoV-2 through direct transmission (person-to-person) has been the focus of most studies on the dynamics of COVID-19. The efficacy of social distancing and mask usage at reducing the risk of direct transmission of COVID-19 has been studied by many researchers. Little or no attention is given to indirect transmission of the virus through shared items, commonly touch surfaces and door handles. The impact of the persistence of SARS-CoV-2 on hard surfaces and in the environment, on the dynamics of COVID-19 remain largely unknown. Also, the current increase in the number of cases despite the strict non-pharmaceutical interventions suggests a need to study the indirect transmission of COVID-19 while incorporating testing of infected individuals as a preventive measure. Assessing the impact of indirect transmission of the virus may improve our understanding of the overall dynamics of COVID-19. We developed a novel deterministic susceptible-exposedinfected- removed-virus-death compartmental model to study the impact of indirect transmission pathway on the spread of COVID-19, the sources of infection, and prevention/control. We fitted the model to the cumulative number of confirmed cases at episode date in Toronto, Canada using a Markov Chain Monte Carlo optimization algorithm. We studied the effect of indirect transmission on the epidemic peak, peak time, epidemic final size and the effective reproduction number, based on different initial conditions and at different stages. Our findings revealed an increase in cases with indirect transmission. Our work highlights the importance of implementing additional preventive and control measures involving cleaning of surfaces, fumigation, and disinfection to lower the spread of COVID-19, especially in public areas like the grocery stores, malls and so on. We conclude that indirect transmission of SARS-CoV- 2 has a significant effect on the dynamics of COVID-19, and there is need to consider this transmission route for effective mitigation, prevention and control of COVID-19 epidemic.

Community structured model for vaccine strategies to control COVID19 spread: a mathematical study (preprint)

Efforts to mitigate the COVID-19 pandemic have relied heavily on non-pharmaceutical interventions ( NPIs ), including physical distancing, hand hygiene, and mask-wearing. However, an effective vaccine is essential to containing the spread of the virus. The first doses were distributed at the end of 2020, but the efficacy, period of immunity it will provide, and percentage of coverage still remain unclear. We developed a compartment model to examine different vaccine strategies for controlling the spread of COVID-19. Our framework accounts for testing rates, test-turnaround times, and vaccination waning immunity. Using reported case data from the city of Toronto, Canada between Mar-Dec, 2020 we defined epidemic phases of infection using contact rates, which depend on individuals’ duration of time spent within the household, workplace/school, or community settings, as well as the probability of transmission upon contact. We investigated the impact of vaccine distribution by comparing different permutations of waning immunity, vaccine coverage and efficacy throughout various stages of NPI’s relaxation in terms of cases, deaths, and household transmission, as measured using the basic reproduction number (R 0 ). We observed that widespread vaccine coverage substantially reduced the number of cases and deaths. In order for NPIs to be relaxed 8 months after vaccine distribution, infection spread can be kept under control with either 60% vaccine coverage, no waning immunity, and 70% efficacy, or with 60% coverage with a 12-month waning immunity and 90% vaccine efficacy. Widespread virus resurgence can result when the immunity wanes under 3 months and/or when NPI’s are relaxed in concomitance with vaccine distribution. In addition to vaccination, our analysis of R 0 showed that the basic reproduction number is reduced by decreasing the tests turnaround time and transmission in the household. While we found that household transmission can decrease following the introduction of a vaccine, public health efforts to reduce test turnaround times remain important for virus containment. Our findings suggest that vaccinating two-thirds of the population with a vaccine that is at least 70% effective may be sufficient for controlling COVID-19 spread, as long as NPI’s are not immediately relaxed.

School and community reopening during the COVID-19 pandemic: a mathematical modeling study (preprint)

BackgroundThe closure of communities, including schools, has been adopted to control the coronavirus disease 2019 (COVID-19) epidemic in most countries. Operating schools safely during the pandemic requires a balance between health risks and the need for in-person learning. We use compartmental models to explore school reopening scenarios. MethodsUsing demographic and epidemiological data between July 31 and November 23, 2020 from the city of Toronto, we developed a Susceptible-Exposed-Asymptomatic-Infectious-Recovered-Hospitalized-Isolated model. Our model with age, household, and community transmission allow us to study the impact of schools open in September 2020. The model mimics the transmission in households, the community, and schools, accounting for differences in infectiousness between adults and children and youth and adults working status. We assessed the extent to which school opening may have contributed to COVID-19 resurgence in the fall and simulated scenarios for the safe reopening of schools up to May 31, 2021. We further considered the impact of the introduction of the new variant of concern. FindingsThough a slight increase in infections among adults (2.8%) and children (5.4%) is anticipated by the end of the year, safe school opening is possible with stringent nonpharmaceutical interventions (NPIs) decreasing the risk of transmission in the community and the household. We found that while school reopening was not the key driver in virus resurgence, but rather it was community spread that determined the outbreak trajectory, brief school closures did reduce infections when transmission risk within the home was low. When considered possible cross-infection amongst households, communities, and schools, we found that home transmission was crucial for mitigating the epidemic and safely operating schools. Simulating the introduction of a new strain with higher infectiousness, we observed substantial increases in infections, even when both schools and communities are closed. InterpretationSchools can open safely under strict maintenance of strict public health measures in the community. The gradual opening of schools and communities can only be achieved by maintaining NPIs and mitigating household transmission risk to avoid the broader escape of infections acquired in schools into the community via households. If the new COVID-19 strain is more infectious for children, public spaces, including schools, should be closed, and additional NPIs, including the use of masks, should be extended to toddlers. FundingThis research was supported by Canadian Institutes of Health Research (CIHR), Natural Sciences and Engineering Research Council of Canada, and York University Research Chair program. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSThe design of a gradual school reopening strategy remains at the heart of decision-making on reopening after shut-downs to control the epidemic. Although available studies have assessed the risk of school reopening by modelling the transmission across schools and communities, it remains unclear whether the risk is due to increased transmission in adults or children and youth.We used GoogleScholar and PubMed searches to identify previous published works. We used te following terms: "school closure", "covid 19 school closure", "reopening schools", "reopening screening school", "school household second wave model". The search of the studies ended in January 2021. Papers in other languages than English and letters were excluded from the search. Two modelling studies examined the effects of screening and delayed school reopening, two other agent-based modelling studies explored the epidemic spread across different age groups. Added-value of this studyWe find that the resurgence of COVID-19 in Toronto in fall 2020 mainly resulted from the increase of contact rate among adults in the community, and that the degree of in-person attendance had the most significant impact on transmission in schools. To our knowledge, our work is the first to investigate the resurgence in infections following school reopening and the impact of risk mitigation measures in schools operation during the pandemic. Our novel and comprehensive model considers the age and household structure, but also considers three different settings, school, household and community. We further examined the effects of self-screening procedures, class size, and schooling days on transmission, which enabled us to compare scenarios of school reopening separately for both adults and children and youth, and model the cross-infection between them to avoid potential underestimation. We found that after schools opened, reducing household transmission was crucial for mitigating the epidemic since it can reduce cross-infection amongst households, communities and schools. Lastly, given the recent report of SARS-CoV-2 variant (VOC202012/01), we investigated the impact of the new variant that may be more infectious in children and youth. Implications of all the available evidenceOur analysis can inform policymakers of planning the safe reopening of schools during COVID-19. We suggest that integrating strict NPIs and school control measures are crucial for safe reopening. When schools are open, reducing transmission risk at home and community is paramount in curbing the spread of COVID-19. Lastly, if children are more susceptible to the new COVID-19 VOC, both schools and community must be closed, the time children spend in essential services locations minimized, and NPIs for those aged less than three years enforced.

Multiplex Sequencing of SARS-Cov-2 genome directly from clinical samples using the Ion Personal Genome Machine (PGM) (preprint)

Various methods have been developed for rapid and high throughput full genome sequencing of SARS-CoV-2. Here, we described a protocol for targeted multiplex full genome sequencing of SARS-CoV-2 genomic RNA directly extracted from human nasopharyngeal swabs using the Ion Personal Genome Machine (PGM). This protocol involves concomitant amplification of 237 gene fragments encompassing the SARS-CoV-2 genome to increase the abundance and yield of viral specific sequencing reads. Five complete and one near-complete genome sequences of SARS-CoV-2 were generated with a single Ion PGM sequencing run. The sequence coverage analysis revealed two amplicons (positions 13751-13965 and 23941-24106), which consistently gave low sequencing read coverage in all isolates except 4Apr20-64-Hu.  We analyzed the potential primer binding sites within these low covered regions and noted that the 4Apr20-64-Hu possess C at positions 13730 and 23929, whereas the other isolates possess T at these positions. The genetic variations observed suggest that the naturally occurring genome variations present in the actively circulating SARS-CoV-2 strains affected the performance of the target enrichment panel of the Ion AmpliSeq™ SARS‑CoV‑2 Research Panel. The possible impact of other genetic sequence variations warrants further investigation, and an improved version of the Ion AmpliSeq™ SARS‑CoV‑2 Research Panel, hence, should be considered. 

Efficacy of stay-at-home policy and transmission of COVID-19 in Toronto, Canada: a mathematical modeling study (preprint)

Background In many parts of the world, restrictive non-pharmaceutical interventions (NPI) that aim to reduce contact rates, including stay-at-home orders, limitations on gatherings, and closure of public places, are being lifted, with the possibility that the epidemic resurges if alternative measures are not strong enough. Here we aim to capture the combination of use of NPIs and reopening measures which will prevent an infection rebound. Methods We employ a SEAIR model with a household structure able to capture the stay-at-home policy (SAHP). To reflect the changes in the SAHP over the course of the epidemic, we vary the SAHP compliance rate, assuming that the time to compliance of all the people requested to stay-at-home follows a Gamma distribution. Using confirmed case data for the City of Toronto, we evaluate basic and instantaneous reproduction numbers and simulate how the average household size, the stay-at-home rate, the efficiency and duration of SAHP implementation, affect the outbreak trajectory. Findings The estimated basic reproduction number R_0 was 2.36 (95% CI: 2.28, 2.45) in Toronto. After the implementation of the SAHP, the contact rate outside the household fell by 39%. When people properly respect the SAHP, the outbreak can be quickly controlled, but extending its duration beyond two months (65 days) had little effect. Our findings also suggest that to avoid a large rebound of the epidemic, the average number of contacts per person per day should be kept below nine. This study suggests that fully reopening schools, offices, and other activities, is possible if the use of other NPIs is strictly adhered to. Interpretation Our model confirmed that the SAHP implemented in Toronto had a great impact in controlling the spread of COVID-19. Given the lifting of restrictive NPIs, we estimated the thresholds values of the maximum number of contacts, probability of transmission and testing needed to ensure that the reopening will be safe, i.e. maintaining an R_t<1.

Efficacy of 'Stay-at-Home' Policy and Transmission of COVID-19 in Toronto, Canada: A Mathematical Modeling Study (preprint)

Background: In many parts of the world, restrictive non-pharmaceutical interventions (NPI) that aim to reduce contact rates, including stay-at-home orders, limitations on gatherings, and closure of public places, are being lifted, with the possibility that the epidemic resurges if alternative measures are not strong enough. Here we aim to capture the combination of use of NPI’s and reopening measures which will prevent an infection rebound.Methods: We employ an SEAIR model with household structure able to capture the stay-at-home policy (SAHP). To reflect the changes in the SAHP over the course of the epidemic, we vary the SAHP compliance rate, assuming that the time to compliance of all the people requested to stay-at-home follows a Gamma distribution. Using confirmed case data for the City of Toronto, we evaluate basic and instantaneous reproduction numbers and simulate how the average household size, the stay-at-home rate, the efficiency and duration of SAHP implementation, affect the outbreak trajectory.Findings: The estimated basic reproduction number R_0 was 2.36 (95% CI: 2.28, 2.45) in Toronto. After the implementation of the SAHP, the contact rate outside the household fell by 39%. When people properly respect the SAHP, the outbreak can be quickly controlled, but extending its duration beyond two months (65 days) had little effect. Our findings also suggest that to avoid a large rebound of the epidemic, the average number of contacts per person per day should be kept below nine. This study suggests that fully reopening schools, offices, and other activities, is possible if the use of other NPIs is strictly adhered to.Interpretation: Our model confirmed that the SAHP implemented in Toronto had a great impact in controlling the spread of COVID-19. Given the lifting of restrictive NPIs, we estimated the thresholds values of maximum number of contacts, probability of transmission and testing needed to ensure that the reopening will be safe, i.e. maintaining an Rt <1.Funding Statement: This research was supported by Canadian Institutes of Health Research (CIHR), Canadian COVID-19 Math Modelling Task Force (NO, BS, JH, JA, JB, JW, JD, HZ), the Natural Sciences and Engineering Research Council of Canada (JH, JA, JB, JW, JD, IM, HZ) and York University Research Chair program (HZ). Declaration of Interests: The authors declare no conflict of interest.

A specialized clinical laboratory center for the coronavirus disease 2019 (COVID-19) in Wuhan Leishenshan Hospital during the COVID-19 outbreak

Responding to the extreme scarcity of medical resources during the early outbreak of the coronavirus disease 2019 (COVID-19) in Wuhan, China, an emergency specialist hospital of Leishenshan started to construct on January 26, 2020 and accommodate patients on February 6, 2020. The clinical laboratory center of Leishenshan Hospital (CLCLH) was constructed at the same time within 11 days to support the treatment of inpatients in Leishenshan Hospital and the testing of suspected patients from different fever clinics in Wuhan. The CLCLH could perform a total of 320 clinic, 299 biochemistry, 31 microorganism and 47 infection and immunity examinations per day. It could also complete an average of 239 nucleic acid tests and 118 SARS-CoV-2 antibody examinations per day. No suspected cases were documented amongst the health care workers during the operation of the CLCLH. The construction and operation experiences of the CLCLH is provided in this study and might be used by other countries as reference. The content of this study is divided into four parts: (1) the establishment of the CLCLH, including its layout and medical resource allocation;(2) the major testing items;(3) the specific procedure of COVID-19 indicator examination;(4) the standardized personal protection measures.