Circulating anti-nuclear autoantibodies in COVID-19 survivors predict long-COVID symptoms.

BACKGROUND: Autoimmunity has been reported in patients with severe COVID-19. We investigated whether antinuclear/extractable-nuclear antibodies (ANAs) were present up to a year after infection, and if they were associated with the development of clinically relevant Post-Acute Sequalae of COVID-19 (PASC) symptoms. METHODS: A rapid assessment line immunoassay was used to measure circulating levels of ANA/ENAs in 106 convalescent COVID-19 patients with varying acute phase severities at 3, 6, and 12 months post-recovery. Patient-reported fatigue, cough, and dyspnea were recorded at each timepoint. Multivariable logistic regression model and receiver-operating curves (ROC) were used to test the association of autoantibodies with patient-reported outcomes and pro-inflammatory cytokines. RESULTS: Compared to age- and sex-matched healthy controls (n=22) and those who had other respiratory infections (n=34), patients with COVID-19 had higher detectable ANAs at 3 months post-recovery (p<0.001). The mean number of ANA autoreactivities per individual decreased from 3 to 12 months (3.99 to 1.55) with persistent positive titers associated with fatigue, dyspnea, and cough severity. Antibodies to U1-snRNP and anti-SS-B/La were both positively associated with persistent symptoms of fatigue (p<0.028, AUC=0.86) and dyspnea (p<0.003, AUC=0.81). Pro-inflammatory cytokines such as tumour necrosis factor alpha (TNFα) and C-reactive protein predicted the elevated ANAs at 12 months. TNFα, D-dimer, and IL-1ß had the strongest association with symptoms at 12 months. Regression analysis showed TNFα predicted fatigue (ß=4.65, p=0.004) and general symptomaticity (ß=2.40, p=0.03) at 12 months. INTERPRETATION: Persistently positive ANAs at 12 months post-COVID are associated with persisting symptoms and inflammation (TNFα) in a subset of COVID-19 survivors. This finding indicates the need for further investigation into the role of autoimmunity in PASC.

Optimal Decision of Dynamic Bed Allocation and Patient Admission with Buffer Wards During an Epidemic

To effectively prevent patients from nosocomial cross-infection and secondary infections, buffer wards for screening infectious patients who cannot be detected due to the incubation period are established in public hospitals in addition to isolation wards and general wards. In this paper, we consider two control mechanisms for three types of wards and patients: one is the dynamic bed allocation to balance the resource utilization among isolation, buffer, and general wards;the other is to effectively control the admission of arriving patients according to the evolution process of the epidemic to reduce mortality for COVID-19, emergency, and elective patients. Taking the COVID-19 pandemic as an example, we first develop a mixed-integer programming (MIP) model to study the joint optimization problem for dynamic bed allocation and patient admission control. Then, we propose a biogeography-based optimization for dynamic bed and patient admission (BBO-DBPA) algorithm to obtain the optimal decision scheme. Furthermore, some numerical experiments are presented to discuss the optimal decision scheme and provide some sensitivity analysis. Finally, the performance of the proposed optimal policy is discussed in comparison with the other different benchmark policies. The results show that adopting the dynamic bed allocation and admission control policy could significantly reduce the total operating cost during an epidemic. The findings can give some decision support for hospital managers in avoiding nosocomial cross-infection, improving bed utilization, and overall patient survival during an epidemic.

Electrostatic Interactions Are the Primary Determinant of the Binding Affinity of SARS-CoV-2 Spike RBD to ACE2: A Computational Case Study of Omicron Variants.

To explore the mechanistic origin that determines the binding affinity of SARS-CoV-2 spike receptor binding domain (RBD) to human angiotensin converting enzyme 2 (ACE2), we constructed the homology models of RBD-ACE2 complexes of four Omicron subvariants (BA.1, BA.2, BA.3 and BA.4/5), and compared them with wild type complex (RBDWT-ACE2) in terms of various structural dynamic properties by molecular dynamics (MD) simulations and binding free energy (BFE) calculations. The results of MD simulations suggest that the RBDs of all the Omicron subvariants (RBDOMIs) feature increased global structural fluctuations when compared with RBDWT. Detailed comparison of BFE components reveals that the enhanced electrostatic attractive interactions are the main determinant of the higher ACE2-binding affinity of RBDOMIs than RBDWT, while the weakened electrostatic attractive interactions determine RBD of BA.4/5 subvariant (RBDBA.4/5) lowest ACE2-binding affinity among all Omicron subvariants. The per-residue BFE decompositions and the hydrogen bond (HB) networks analyses indicate that the enhanced electrostatic attractive interactions are mainly through gain/loss of the positively/negatively charged residues, and the formation or destruction of the interfacial HBs and salt bridges can also largely affect the ACE2-binding affinity of RBD. It is worth pointing out that since Q493R plays the most important positive contribution in enhancing binding affinity, the absence of this mutation in RBDBA.4/5 results in a significantly weaker binding affinity to ACE2 than other Omicron subvariants. Our results provide insight into the role of electrostatic interactions in determining of the binding affinity of SARS-CoV-2 RBD to human ACE2.

Translation suppression underlies the restrained COVID-19 mRNA vaccine response in the high-risk immunocompromised group.

Background: Immunocompromised (IC) patients show diminished immune response to COVID-19 mRNA vaccines (Co-mV). To date, there is no 'empirical' evidence to link the perturbation of translation, a rate-limiting step for mRNA vaccine efficiency (VE), to the dampened response of Co-mV. Materials and methods: Impact of immunosuppressants (ISs), tacrolimus (T), mycophenolate (M), rapamycin/sirolimus (S), and their combinations on Pfizer Co-mV translation were determined by the Spike (Sp) protein expression following Co-mV transfection in HEK293 cells. In vivo impact of ISs on SARS-CoV-2 spike specific antigen (SpAg) and associated antibody levels (IgGSp) in serum were assessed in Balb/c mice after two doses (2D) of the Pfizer vaccine. Spike Ag and IgGSp levels were assessed in 259 IC patients and 50 healthy controls (HC) who received 2D of Pfizer or Moderna Co-mV as well as in 67 immunosuppressed solid organ transplant (SOT) patients and 843 non-transplanted (NT) subjects following three doses (3D) of Co-mV. Higher Co-mV concentrations and transient drug holidays were evaluated. Results: We observed significantly lower IgGSP response in IC patients (p<0.0001) compared to their matched controls in 2D and 3D Co-mV groups. IC patients on M or S showed a profound dampening of IgGSP response relative to those that were not on these drugs. M and S, when used individually or in combination, significantly attenuated the Co-mV-induced Sp expression, whereas T did not exert significant influence. Sirolimus combo pretreatment in vivo significantly attenuated the Co-mV induced IgMSp and IgGSp production, which correlated with a decreasing trend in the early levels (after day 1) of Co-mV induced Sp immunogen levels. Neither higher Co-mV concentrations (6µg) nor withholding S for 1-day could overcome the inhibition of Sp protein levels. Interestingly, 3-days S holiday or using T alone rescued Sp levels in vitro. Conclusions: This is the first study to demonstrate that ISs, sirolimus and mycophenolate inhibited Co-mV-induced Sp protein synthesis via translation repression. Selective use of tacrolimus or drug holiday of sirolimus can be a potential means to rescue translation-dependent Sp protein production. These findings lay a strong foundation for guiding future studies aimed at improving Co-mV responses in high-risk IC patients.

Transcriptome and DNA methylome analysis of peripheral blood samples reveals incomplete restoration and transposable element activation after 3-months recovery of COVID-19.

Comprehensive analyses showed that SARS-CoV-2 infection caused COVID-19 and induced strong immune responses and sometimes severe illnesses. However, cellular features of recovered patients and long-term health consequences remain largely unexplored. In this study, we collected peripheral blood samples from nine recovered COVID-19 patients (median age of 36 years old) from Hubei province, China, 3 months after discharge as well as 5 age- and gender-matched healthy controls; and carried out RNA-seq and whole-genome bisulfite sequencing to identify hallmarks of recovered COVID-19 patients. Our analyses showed significant changes both in transcript abundance and DNA methylation of genes and transposable elements (TEs) in recovered COVID-19 patients. We identified 425 upregulated genes, 214 downregulated genes, and 18,516 differentially methylated regions (DMRs) in total. Aberrantly expressed genes and DMRs were found to be associated with immune responses and other related biological processes, implicating prolonged overreaction of the immune system in response to SARS-CoV-2 infection. Notably, a significant amount of TEs was aberrantly activated and their activation was positively correlated with COVID-19 severity. Moreover, differentially methylated TEs may regulate adjacent gene expression as regulatory elements. Those identified transcriptomic and epigenomic signatures define and drive the features of recovered COVID-19 patients, helping determine the risks of long COVID-19, and guiding clinical intervention.

Autoimmunity is a hallmark of post-COVID syndrome.

Autoimmunity has emerged as a characteristic of the post-COVID syndrome (PCS), which may be related to sex. In order to further investigate the relationship between SARS-CoV-2 and autoimmunity in PCS, a clinical and serological assessment on 100 patients was done. Serum antibody profiles against self-antigens and infectious agents were evaluated by an antigen array chip for 116 IgG and 104 IgM antibodies. Thirty pre-pandemic healthy individuals were included as a control group. The median age of patients was 49 years (IQR: 37.8 to 55.3). There were 47 males. The median post-COVID time was 219 (IQR: 143 to 258) days. Latent autoimmunity and polyautoimmunity were found in 83% and 62% of patients, respectively. Three patients developed an overt autoimmune disease. IgG antibodies against IL-2, CD8B, and thyroglobulin were found in more than 10% of the patients. Other IgG autoantibodies, such as anti-interferons, were positive in 5-10% of patients. Anti-SARS-CoV-2 IgG antibodies were found in > 85% of patients and were positively correlated with autoantibodies, age, and body mass index (BMI). Few autoantibodies were influenced by age and BMI. There was no effect of gender on the over- or under-expression of autoantibodies. IgG anti-IFN-λ antibodies were associated with the persistence of respiratory symptoms. In summary, autoimmunity is characteristic of PCS, and latent autoimmunity correlates with humoral response to SARS-CoV-2.

Gut Microbiota May Not Be Fully Restored in Recovered COVID-19 Patients After 3-Month Recovery.

Coronavirus disease 2019 (COVID-19) has infected over 124 million people worldwide. In addition to the development of therapeutics and vaccines, the evaluation of the sequelae in recovered patients is also important. Recent studies have indicated that COVID-19 has the ability to infect intestinal tissues and to trigger alterations of the gut microbiota. However, whether these changes in gut microbiota persist into the recovery stage remains largely unknown. Here, we recruited seven healthy Chinese men and seven recovered COVID-19 male patients with an average of 3-months after discharge and analyzed their fecal samples by 16S rRNA sequencing analysis to identify the differences in gut microbiota. Our results suggested that the gut microbiota differed in male recovered patients compared with healthy controls, in which a significant difference in Chao index, Simpson index, and ß-diversity was observed. And the relative abundance of several bacterial species differed clearly between two groups, characterized by enrichment of opportunistic pathogens and insufficiency of some anti-inflammatory bacteria in producing short chain fatty acids. The above findings provide preliminary clues supporting that the imbalanced gut microbiota may not be fully restored in recovered patients, highlighting the importance of continuous monitoring of gut health in people who have recovered from COVID-19.

Strategies used to meet the challenges of mass COVID-19 vaccination by the pharmacy department in a large academic medical center.

PURPOSE: Highly effective coronavirus disease 2019 (COVID-19) vaccines have brought hope for ending the pandemic. Unprecedented mass vaccination started first among healthcare workers. The aim of this report is to describe key strategies undertaken by a large hospital pharmacy department to meet the challenges of preparing a large quantity of COVID-19 vaccine doses in a short period of time. SUMMARY: MedStar Washington Hospital Center (MWHC) was in the first group of hospitals in Washington, DC, to receive Pfizer-BioNTech vaccine in December 2020. The pharmacy department faced challenges including stringent vaccine storage requirements, a need for specific equipment and workflow, limited funding, and staffing constraints. The pharmacy department's senior leaders defined pharmacy responsibilities, budgeted for equipment, participated in vaccination center design, and instructed pharmacy informatics personnel. The vaccine coordinators were appointed to oversee all vaccination-related operations. An ultra-low temperature freezer was installed 2 weeks before arrival of the first shipment of vaccine. All pharmacy order entry tools and operating procedures were standardized, and staff training and schedules were finalized by December 15. The first dose of the vaccine was administered on December 16 at the vaccination center. Pharmacy staff members dispensed the vaccine doses and monitored patients. By January 6, 2021, MWHC had vaccinated 3,812 employees with their first vaccine dose, with an average of 228 doses administered daily. CONCLUSION: Key strategies such as systemic coordination, early preparation, detailed planning, operating procedure development, and staff education and engagement proved successful in facilitating preparation of thousands of COVID-19 vaccine doses for hospital employees within a short period of time.

Exogenous Coronavirus Interacts With Endogenous Retrotransposon in Human Cells.

There is an increased global outbreak of diseases caused by coronaviruses affecting respiratory tracts of birds and mammals. Recent dangerous coronaviruses are MERS-CoV, SARS-CoV, and SARS-CoV-2, causing respiratory illness and even failure of several organs. However, profound impact of coronavirus on host cells remains elusive. In this study, we analyzed transcriptome of MERS-CoV, SARS-CoV, and SARS-CoV-2 infected human lung-derived cells, and observed that infection of these coronaviruses all induced increase of retrotransposon expression with upregulation of TET genes. Upregulation of retrotransposon was also observed in SARS-CoV-2 infected human intestinal organoids. Retrotransposon upregulation may lead to increased genome instability and enhanced expression of genes with readthrough from retrotransposons. Therefore, people with higher basal level of retrotransposon such as cancer patients and aged people may have increased risk of symptomatic infection. Additionally, we show evidence supporting long-term epigenetic inheritance of retrotransposon upregulation. We also observed chimeric transcripts of retrotransposon and SARS-CoV-2 RNA for potential human genome invasion of viral fragments, with the front and the rear part of SARS-CoV-2 genome being easier to form chimeric RNA. Thus, we suggest that primers and probes for nucleic acid detection should be designed in the middle of virus genome to identify live virus with higher probability. In summary, we propose our hypothesis that coronavirus invades human cells and interacts with retrotransposon, eliciting more severe symptoms in patients with underlying diseases. In the treatment of patients with coronavirus infection, it may be necessary to pay more attention to the potential harm contributed by retrotransposon dysregulation.

Human Blastocyst is Susceptible to SARS-CoV-2 Infection based on Protein Level Examination of Key Entry Factors in Human Oocytes and Early Embryos (preprint)

Objective ACE2, TMPRSS2 and NRP1 are key factors for SARS-CoV-2 infection. Here, we used immunofluorescence to examine the expression patterns of ACE2, TMPRSS2 and NRP1 in human oocytes and different stages of preimplantation embryos to investigated the susceptibility to be infected by SARS-CoV-2.Methods We collected human GV oocytes and different stages of early embryos donated by patients and then performed immunofluorescence followed by confocal microscopy for signals of ACE2, TMPRSS2 and NRP1 proteins in these oocytes and embryos.Results We found that ACE2 was abundant in both inner cell mass and trophectoderm at blastocyst stage, while TMPRSS2 was mainly enriched in trophectoderm. Both of the two factors had faint signal in cleavage embryos and oocytes. In contrast, NRP1 was barely detectable in oocytes or any stage of early embryos. Conclusion Taken together, we propose that human blastocysts, instead of human oocytes and other stages of early embryos, are susceptible to be infected by SARS-CoV-2. Therefore, specific attention should be paid to manipulation of human blastocysts in assisted reproductive technology.

Suggestions on cleavage embryo and blastocyst vitrification/transfer based on expression profile of ACE2 and TMPRSS2 in current COVID-19 pandemic.

An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is leading to an unprecedented worldwide health crisis. SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2. Our objectives are to analysis the expression profile of ACE2 and TMPRSS2 in human spermatogenic cells, follicle cells, and preimplantation embryos, thereby providing mechanistic insights into viral entry and viral impact on reproduction. We found that ACE2 is mainly expressed during gametogenesis in spermatogonia and oocytes of antral follicles, granulosa cells of antral follicles and pre-ovulatory follicles, while TMPRSS2 almost has no expression in spermatogenic cells, oocytes or granulosa cells. In preimplantation embryos, ACE2 is expressed in early embryos before eight-cell stage, and trophectoderm of late blastocysts, while TMPRSS2 initiates its robust expression in late blastocyst stage. ACE2 and TMPRSS2 only show significant co-expression in trophectoderm of late blastocysts in all above cell types. We speculate that trophectoderm of late blastocysts is susceptible to SARS-CoV-2, and that the chance of SARS-CoV-2 being passed on to offspring through gametes is very low. Therefore, we propose that fertility preservation for COVID-19 patients is relatively safe and rational. We also recommend embryo cryopreservation and embryo transfer into healthy recipient mother at cleavage stage instead of blastocyst stage. Moreover, we unexpectedly found that co-expression pattern of ACE2 and TMPRSS2 in oocytes and preimplantation embryos in human, rhesus monkey and mouse are totally different, so animal models have significant limitations for evaluating transmission risk of SARS-CoV-2 in reproduction.

Evaluating the impact of COVID-19 on male reproduction.

Invasion or damage of the male reproductive system is one of the reported outcomes of viral infection. Current studies have documented that SARS-CoV-2, which causes COVID-19, can damage the male reproductive system in large part by inflammatory damage caused by a cytokine storm. However, whether SARS-CoV-2 can infect the human testis directly and enter semen is controversial. Other adverse effects of SARS-CoV-2 on male reproduction are also of concern and require comprehensive evaluation. Here, we analyze the invasiveness of SARS-CoV-2 in the testis and examine reported mechanisms by which SARS-CoV-2 interferes with male reproduction. Long-term implications of SARS-CoV-2 infection on male reproduction are also discussed. It should be emphasized that although COVID-19 may induce testicular damage, a substantial decrease in male reproductive capacity awaits clinical evidence. We propose that there is an urgent need to track male COVID-19 patients during their recovery. The development of suitable experimental models, including human reproductive organoids, will be valuable to further investigate the viral impact on reproduction for current and future pandemics.

Anti-HIV drug repurposing against SARS-CoV-2.

A novel severe acute respiratory syndrome human coronavirus (SARS HCoV) was identified from respiratory illness patients (named SARS-CoV-2 by ICTV) in December 2019 and has recently emerged as a serious threat to world public health. However, no approved drugs have been found to effectively inhibit the virus. Since it has been reported that HIV protease inhibitors can be used as anti-SARS drugs by targeting SARS-CoV-1 3CLpro, we chose six approved anti-HIV drugs and investigated their binding interactions with 3CLpro to evaluate their potential to become clinical drugs for the new coronavirus pneumonia (COVID-19) caused by SARS-CoV-2 infection. The molecular docking results indicate that the 3CLpro of SARS-CoV-2 has a higher binding affinity for all the studied inhibitors than does SARS-CoV-1. Two docking complexes (indinavir and darunavir) with high docking scores were further subjected to MM-PBSA binding free energy calculations to detail the molecular interactions between these two protease inhibitors and SARS HCoV 3CLpro. Our results show that, among the inhibitors tested, darunavir has the highest binding affinity with SARS-CoV-2 and SARS-CoV-1 3CLpro, indicating that it may have the potential to be used as an anti-COVID-19 clinical drug. The mechanism behind the increased binding affinity of HIV protease inhibitors toward SARS-CoV-2 3CLpro (as compared to SARS-CoV-1) was investigated by MD simulations. Our study provides insight into the possible role of structural flexibility during interactions between SARS HCoV 3CLpro and inhibitors and sheds light on structure-based design of anti-COVID-19 drugs targeting SARS-CoV-2 3CLpro.

SARS-CoV-2 infection associated with hepatitis in an infant with X-linked severe combined immunodeficiency.

X-linked severe combined immunodeficiency (X-SCID) is a disorder of adaptive immunity caused by mutations in the IL-2 receptor common gamma chain gene resulting in deficiencies of T and natural killer cells, coupled with severe dysfunction in B cells. X-SCID is lethal without allogeneic stem cell transplant or gene therapy due to opportunistic infections. An infant with X-SCID became infected with SARS-CoV-2 while awaiting transplant. The patient developed severe hepatitis without the respiratory symptoms typical of COVID-19. He was treated with convalescent plasma, and thereafter was confirmed to have SARS-CoV-2 specific antibodies, as detected with a microfluidic antigen array. After resolution of the hepatitis, he received a haploidentical CD34 selected stem cell transplant, without conditioning, from his father who had recovered from COVID-19. SARS CoV-2 was detected via RT-PCR on nasopharyngeal swabs until 61 days post transplantation. He successfully engrafted donor T and NK cells, and continues to do well clinically.

Analysis of Peripheral Blood IL-6 and Leukocyte Characteristics in 364 COVID-19 Patients of Wuhan.

SARS-CoV-2, the pathogen of COVID-19, is spreading around the world. Different individuals infected with COVID-19 have different manifestations. It is urgent to determine the risk factors of disease progress of COVID-19. 364 patients diagnosed with COVID-19, who were admitted to Wuhan Pulmonary Hospital from February 3, 2020 to March 16, 2020, were divided into mild, ordinary, severe, and critical groups, according to Chinese novel coronavirus pneumonia diagnosis and treatment plan. Peripheral blood IL-6 and leukocyte characteristics were analyzed, to evaluate the correlation with the severity of COVID-19. The levels of peripheral blood IL-6 were 2.35 ± 0.46 pg/ml (mild), 6.48 ± 1.13 pg/ml (ordinary), 20.30 ± 5.15 pg/ml (severe), and 123.48 ± 44.31 pg/ml (critical). The leukocytes were 5.70 ± 0.41×109/L (mild), 6.21 ± 0.14×109/L (ordinary), 6.37 ± 0.26×109/L (severe), and 10.03 ± 1.43×109/L (critical). The lymphocytes were 1.46 ± 0.19×109/L (mild), 1.89 ± 0.14×109/L (ordinary), 1.26 ± 0.07×109/L (severe), and 1.17 ± 0.23×109/L (critical). The neutrophils were 3.63 ± 0.36×109/L (mild), 3.78 ± 0.11×109/L (ordinary), 4.47 ± 0.25×109/L (severe), and 7.92 ± 1.19×109/L (critical). The monocytes were 0.42 ± 0.05×109/L (mild), 0.44 ± 0.01×109/L (ordinary), 0.46 ± 0.02×109/L (severe), and 0.78 ± 0.25×109/L (critical). Conclusively, increase of peripheral blood IL-6 and decrease of lymphocytes can be used as the indicators of severe COVID-19. The increase of neutrophils and monocytes was noticed in critical cases of COVID-19, suggesting that the increase of neutrophils and monocytes should be considered as risk factors of critical cases of COVID-19. Peripheral blood IL-6 and leukocyte characteristics were also analyzed in different age groups. The increase of serum IL-6, decrease of lymphocytes, and increase of neutrophils were noticed in patients over 60 years old.

Characteristics and Effectiveness of the Coronavirus Disease 2019 (COVID-19) Prevention and Control in a Representative City in China.

BACKGROUND SARS-CoV-2 has caused a pandemic. Control measures differ among countries. It is necessary to assess the effectiveness of these control measures. MATERIAL AND METHODS We collected the data of COVID-19 patients and control measures between January 18, 2020 and September 18, 2020 from the Changshou District and analyzed the clinical characteristics, epidemiological data, and the adjustment of policies to assess the effectiveness of control measures. The control of COVID-19 was divided into 2 stages, with the lifting of lockdown in Hubei province (March 25, 2020) as a dividing line. RESULTS We identified 32 patients through different means in the first stage. All the imported patients entered this area before the lockdown. In 93.1% of patients, the last exposure occurred before the implementation of the stay-at-home order and centralized isolation. Tracing of high-risk people and RT-PCR screening identified 56.3% of cases. In the second stage, all the high-risk people were under centralized isolation. Nine asymptomatic patients were identified. City lockdown and stay-at-home orders were not issued again, and no second-generation patients were found. CONCLUSIONS We have provided a successful model to control the transmission of COVID-19 in a short period.

Definition and retrospective application of a clinical scoring system for COVID-19 triage at presentation.

BACKGROUND: A simple scoring system for triage of suspected patients with COVID-19 is lacking. METHODS: A multi-disciplinary team developed a screening score taking into account epidemiology history, clinical feature, radiographic feature, and routine blood test. At fever clinics, the screening score was used to identify the patients with moderate to high probability of COVID-19 among all the suspected patients. The patients with moderate to high probability of COVID-19 were allocated to a single room in an isolation ward with level-3 protection. And those with low probability were allocated to a single room in a general ward with level-2 protection. At the isolation ward, the screening score was used to identify the confirmed and probable cases after two consecutive real-time reverse transcription polymerase chain reaction (RT-PCR) tests. The data in the People's Hospital of Changshou District were used for internal validation and those in the People's Hospital of Yubei District for external validation. RESULTS: We enrolled 76 and 40 patients for internal and external validation, respectively. In the internal validation cohort, the area under the curve of receiver operating characteristics (AUC) was 0.96 [95% confidence interval (CI): 0.89-0.99] for the diagnosis of moderate to high probability of cases among all the suspected patients. Using 60 as cut-off value, the sensitivity and specificity were 88% and 93%, respectively. In the isolation ward, the AUC was 0.94 (95% CI: 0.83-0.99) for the diagnosis of confirmed and probable cases. Using 90 as cut-off value, the sensitivity and specificity were 78% and 100%, respectively. These results were confirmed in the validation cohort. CONCLUSION: The scoring system provides a reference on COVID-19 triage in fever clinics to reduce misdiagnosis and consumption of protective supplies.The reviews of this paper are available via the supplemental material section.