This study aims to establish an antibody detection method for porcine deltacoronavirus (PDCoV). The recombinant proteins PDCoV-N1 and PDCoV-N2 were expressed via the prokaryotic plasmid pColdII harboring the N gene sequence of the PDCoV strain CH/XJYN/2016. The reactivity and specificity of PDCoV-N1 and PDCoV-N2 with anti-PEDV sera were analyzed after the recombinant proteins were analyzed by SDS-PAGE and purified by the Ni-NTA Superflow Cartridge. Meanwhile, Western blotting and indirect immunofluorescence assay were carried out separately to validate the recombinant proteins PDCoV-N1 and PDCoV-N2. Finally, we established an indirect ELISA method based on the recombinant protein PDCoV-N2 after optimizing the conditions and tested the sensitivity, specificity, and reproducibility of the method. Then, the established method was employed to examine 102 clinical serum samples. The recombinant protein PDCoV-N2 showed low cross-reactivity with anti-PEDV sera. The optimal conditions of the indirect ELISA method based on PDCoV-N2 were as follows: the antigen coating concentration of 1.25 μg/mL and coating at 37 ℃ for 1 h; blocking by BSA overnight at 4 ℃; serum sample dilution at 1:50 and incubation at 37 ℃ for 1 h; secondary antibody dilution at 1:80 000 and incubation at 37 ℃ for 1 h; color development with TMB chromogenic solution at 37 ℃ for 10 min. The S/P value ≥ 0.45, ≤0.38, and between 0.45 and 0.38 indicated that the test sample was positive, negative, and suspicious, respectively. The testing results of the antisera against porcine epidemic diarrhea virus (PEDV), porcine circovirus 2 (PCV2), transmissible gastroenteritis virus (TGEV), foot-and-mouth disease virus (FMDV), and African swine fever virus (ASFV) showed that the S/P values were all less than 0.38. The testing results of the 800-fold diluted anti-PDCoV sera were still positive. The results of the inter- and intra-batch tests showed that the coefficients of variation of this method were less than 10%. Clinical serum sample test results showed the coincidence rate between this method and neutralization test was 94.12%. In this study, an ELISA method for the detection of anti-PDCoV antibodies was successfully established based on the truncated N protein of PDCoV. This method is sensitive, specific, stable, and reproducible, serving as a new method for the clinical diagnosis of PDCoV.
Animals ; Enzyme-Linked Immunosorbent Assay/methods* ; Swine ; Antibodies, Viral/blood* ; Recombinant Proteins/genetics* ; Deltacoronavirus/isolation & purification* ; Coronavirus Infections/virology* ; Swine Diseases/diagnosis* ; Coronavirus Nucleocapsid Proteins ; Sensitivity and Specificity

Severe cases infected with the coronavirus disease 2019 (COVID-19), named by the World Health Organization (WHO) on Feb. 11, 2020, tend to present a hypercatabolic state because of severe systemic consumption, and are susceptible to stress ulcers and even life-threatening gastrointestinal bleeding. Endoscopic diagnosis and treatment constitute an irreplaceable part in the handling of severe COVID-19 cases. Endoscopes, as reusable precision instruments with complicated structures, require more techniques than other medical devices in cleaning, disinfection, sterilization, and other reprocessing procedures. From 2016 to 2019, health care-acquired infection caused by improper endoscope reprocessing has always been among the top 5 on the list of top 10 health technology hazards issued by the Emergency Care Research Institute. Considering the highly infective nature of COVID-19 and the potential aerosol contamination therefrom, it is of pivotal significance to ensure that endoscopes are strictly reprocessed between uses. In accordance with the national standard "Regulation for Cleaning and Disinfection Technique of Flexible Endoscope (WS507-2016)," we improved the workflow of endoscope reprocessing including the selection of chemicals in an effort to ensure quality control throughout the clinical management towards COVID-19 patients. Based on the experience we attained from the 12 severe COVID-19 cases in our hospital who underwent endoscopy 23 times in total, the article provides an improved version of endoscopic reprocessing guidelines for bedside endoscopic diagnosis and treatment on COVID-19 patients for reference.
Adult ; Aged ; Aged, 80 and over ; Betacoronavirus ; China ; Coronavirus Infections ; diagnosis ; therapy ; Cross Infection ; prevention & control ; Disinfection ; methods ; Endoscopes ; virology ; Equipment Contamination ; prevention & control ; Female ; Humans ; Male ; Middle Aged ; Pandemics ; Peracetic Acid ; Personal Protective Equipment ; Pneumonia, Viral ; diagnosis ; therapy ; Sterilization ; methods ; Workflow

As of Apr. 22, 2020, the World Health Organization (2020) has reported over 2.4 million confirmed coronavirus disease 2019 (COVID-19) patients and 169 151 deaths. Recent articles have uncovered genomic characteristics and clinical features of COVID-19 (Chan et al., 2020; Chang et al., 2020; Guan et al., 2020; Zhu et al., 2020), while our understanding of COVID-19 is still limited. As suggested by guidelines promoted by the General Office of National Health Commission of the People's Republic of China (2020) (from Versions 1 to 6), discharged standards for COVID-19 were still dependent on viral real-time polymerase chain reaction (RT-PCR) tests of respiratory specimens, showing that recovered COVID-19 patients with twice negative RT-PCR could meet discharge criteria. Here, we examined two cases in which nucleic acid test results were inconsistent with clinical and radiological findings, leading to suboptimal care.
Adult ; Betacoronavirus ; China ; Clinical Laboratory Techniques ; Coronavirus Infections ; diagnosis ; transmission ; Female ; Humans ; Male ; Middle Aged ; Pandemics ; Patient Discharge ; Pneumonia, Viral ; diagnosis ; transmission ; Real-Time Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; Sputum ; virology

The recently emerged novel coronavirus pneumonia, named the coronavirus disease 2019 (COVID-19), shares several clinical characteristics with severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), and spread rapidly throughout China in December of 2019 (Huang et al., 2020). The pathogen 2019 novel coronavirus (2019-nCoV) is now named SARS coronavirus 2 (SARS-CoV-2) and is highly infectious. As of Apr. 9, 2020, over 80 000 confirmed cases had been reported, with an estimated mortality rate of 4.0% (Chinese Center for Disease Control and Prevention, 2020). Person-to-person transmission and familial clustering have been reported (Chan et al., 2020; Nishiura et al., 2020; Phan et al., 2020). However, there is no evidence of fetal intrauterine infection in pregnant women who have been infected with SARS-CoV-2 in their third trimester (Chen et al., 2020). It is unclear whether breastfeeding transmits the virus from previously infected and recovered mothers to their babies. Here we report the clinical course of a pregnant woman with COVID-19. In order to determine whether SARS-CoV-2 can be transmitted to newborns through breastfeeding, we measured viral RNA in the patient's breastmilk samples at different time points after delivery.
Adult ; Betacoronavirus ; Breast Feeding ; China ; Coronavirus Infections ; diagnosis ; Female ; Humans ; Infant, Newborn ; Infectious Disease Transmission, Vertical ; Milk, Human ; virology ; Pandemics ; Pneumonia, Viral ; diagnosis ; Pregnancy ; Pregnancy Complications, Infectious ; virology ; RNA, Viral ; isolation & purification

We optimized a fluorescent quantitative polymerase chain reaction (qPCR) assay system for rapid and real time detection of SARS-CoV-2 RNA. The results show that the lowest dilution of RNA samples used for the detection of SARS-CoV-2 RNA could reach 1/10 000 (the initial value is set as 10 ng/μL). Moreover, the cycle threshold (Ct) for samples of clinically diagnosed COVID-19 was lower than 35 or 40. The sensitivity of this method was satisfactory. The results were consistent with those of the COVID-19 detection kit on the market under the same conditions, but the number of cycles required was shortened by about 2. Therefore, the optimized assay developed in this study can be used in screening and early clinical diagnosis. Our work provides a tool to facilitate rapid clinical diagnosis of COVID-19.
Betacoronavirus ; genetics ; isolation & purification ; Coronavirus Infections ; diagnosis ; virology ; Early Diagnosis ; Humans ; Pandemics ; Pneumonia, Viral ; diagnosis ; virology ; Polymerase Chain Reaction ; methods ; standards ; RNA, Viral ; analysis ; genetics ; Sensitivity and Specificity ; Time Factors

The ongoing outbreak of the coronavirus disease 2019 (COVID-19) as named by the World Health Organization has millions of confirmed cases around the world and has claimed hundreds of thousands of lives. The virus was named SARS-CoV-2 in February by International Committee on Taxonomy of Viruses. COVID-19 presents as fever, dry cough, dyspnea, headache and pneumonia. In a small subset of severe cases, the disease quickly progresses to respiratory failure and even death. Since the 21st century, there have been three major outbreaks caused by human coronaviruses, including the severe acute respiratory syndrome (SARS) that broke out in 2003, the Middle East respiratory syndrome (MERS) in 2012, and the recent pandemic of COVID-19. Since 2003, significant progress has been made in the study of SARS-CoV and MERS-CoV concerning their natural origins, pathogenesis, antiviral development and vaccine design. Since SARS-CoV-2 and SARS-CoV are closely related, previous findings on SARS-CoV are highly relevant to a better understanding as well as diagnosis, treatment, prevention and control of SARS-CoV-2. In this review, we highlight recent progresses in the field; compare the biological characteristics of SARS-CoV and SARS-CoV-2; summarize the urgently-needed diagnostic, treatment, prevention and control options; and provide future perspectives for the outcome of the outbreak and research questions to be answered, including some of the difficulties in vaccine development. Hopefully, our comments and suggestions would prove useful for the control of the SARS-CoV-2 epidemic in China and the world.
Antiviral Agents ; pharmacology ; therapeutic use ; Betacoronavirus ; drug effects ; immunology ; pathogenicity ; Coronavirus Infections ; diagnosis ; prevention & control ; therapy ; virology ; Humans ; Middle East Respiratory Syndrome Coronavirus ; drug effects ; immunology ; pathogenicity ; Pandemics ; prevention & control ; Pneumonia, Viral ; diagnosis ; prevention & control ; therapy ; virology ; SARS Virus ; drug effects ; immunology ; pathogenicity ; Severe Acute Respiratory Syndrome ; diagnosis ; prevention & control ; therapy ; virology ; Viral Vaccines

OBJECTIVE: To explore the feasibility of surgical treatment for cancer patients complicated with corona virus disease 2019 (COVID-19). METHODS: The management and clinical outcome of a sigmoid cancer patient with COVID-19 were analyzed. RESULTS: The inflammation indicators and fever of this patient were effectively controlled and the lung lesions remained stable after active anti-viral treatment, then the radical colorectomy was performed after the viral negative conversion for twice. CONCLUSIONS The case indicates that it may feasible to undergo radical tumor surgery for cancer patients with COVID-19 after the virus nucleic acid testing turns negative and more studies are needed to confirm this conclusion.
Antiviral Agents ; therapeutic use ; Betacoronavirus ; Clinical Laboratory Techniques ; Colonic Neoplasms ; complications ; surgery ; virology ; Coronavirus Infections ; complications ; diagnosis ; drug therapy ; Fever ; Humans ; Nucleic Acid Amplification Techniques ; Pandemics ; Pneumonia, Viral ; complications ; diagnosis ; drug therapy

2019-nCoV epidemic was firstly reported at late December of 2019 and has caused a global outbreak of COVID-19 now. Saliva, a biofluid largely generated from salivary glands in oral cavity, has been reported 2019-nCoV nucleic acid positive. Besides lungs, salivary glands and tongue are possibly another hosts of 2019-nCoV due to expression of ACE2. Close contact or short-range transmission of infectious saliva droplets is a primary mode for 2019-nCoV to disseminate as claimed by WHO, while long-distance saliva aerosol transmission is highly environment dependent within indoor space with aerosol-generating procedures such as dental practice. So far, no direct evidence has been found that 2019-nCoV is vital in air flow for long time. Therefore, to prevent formation of infectious saliva droplets, to thoroughly disinfect indoor air and to block acquisition of saliva droplets could slow down 2019-nCoV dissemination. This review summarizes diagnostic value of saliva for 2019-nCoV, possibly direct invasion into oral tissues, and close contact transmission of 2019-nCoV by saliva droplets, expecting to contribute to 2019-nCoV epidemic control.
Betacoronavirus ; isolation & purification ; pathogenicity ; Clinical Laboratory Techniques ; Coronavirus Infections ; diagnosis ; transmission ; Humans ; Mouth ; virology ; Pandemics ; Peptidyl-Dipeptidase A ; metabolism ; Pharynx ; virology ; Pneumonia, Viral ; diagnosis ; transmission ; SARS Virus ; isolation & purification ; pathogenicity ; Saliva ; virology

Betacoronavirus ; Coronavirus Infections ; diagnosis ; Diagnosis, Differential ; Diagnostic Imaging ; methods ; Humans ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral ; diagnosis ; virology ; Radiography, Thoracic ; methods ; Tomography, X-Ray Computed ; methods

Clinical Laboratory Techniques ; Coronavirus Infections ; diagnosis ; Hospitals, General ; Humans ; Pandemics ; Pneumonia, Viral ; diagnosis ; Singapore ; Virology ; methods