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

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

OBJECTIVES: To analyze the clinical characteristics of fecal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid-positive in patients with coronavirus dasease 2019 (COVID-19) and to provide a scientific basis for the prevention and control of this disease. METHODS: The clinical data of 16 patients with fecal SARS-CoV-2 nucleic acid positive, who hospitalized in the North Branch of the First Hospital of Changsha (Changsha Public Health Rescue Center) from January to February 2020, were retrospectively analyzed. Their clinical manifestations, laboratory data and imaging data were summarized. RESULTS: Among the 16 patients, there were 9 males (56.25%) and 7 females (43.75%), the ratio of males to females was 1∶1.29. The age of onset was (43.3±14.6) years. There were 15 patients with contact history of Wuhan, 1 patient with contact history of local patient.Twelve patients were common type (75%), and 4 patients were severe type (25%). Clinical symptoms included fever in 14 patients (87.5%), cough in 12 patients (75%), shortness of breath in 5 patients (31.25%), pharyngalgia in 10 patients (62.5%), fatigue in 7 patients (43.75%), and diarrhea in 4 patients (25%). There were 14 patients (87.5%) with normal or decreased white blood cell count, 11 patients (68.75%) with decreased lymphocyte count, 15 patients (93.75%) with increased erythrocyte sedimentation rate, 13 patients (81.25%) with increased hypersensitivity C-reactive protein, 5 patients (31.25%) with increased procalcitonin, and 8 patients (50%) with increased serum ferritin in peripheral blood, and stool routine was basically normal. Compared with the common type, there was significant difference in the white blood cell and lymphocyte counts in the severe type (<0.01); the infection indicators, such as hypersensitivity C-reactive protein and serum ferritin, were significantly increased, with significant difference (all <0.01); but the procalcitonin and erythrocyte sedimentation rate was not significantly different (both >0.05). Chest CT mainly showed patchy shadows and interstitial changes. According to imaging examination, 4 patients (25%) showed unilateral pneumonia and 12 patients (75%) showed bilateral pneumonia. CONCLUSIONS The patients have the clinical symptoms of COVID-19, but gastrointestinal symptoms (such as diarrhea) are more common, and the changes of white blood cell count, lymphocyte count, hypersensitivity C-reactive protein, ferritin are more obvious in severe patients.The positivity of fecal nucleic acid suggests the possibility of digestive tract transmission of SARS-CoV-2, and fecal nucleic acid testing can be used as a routine testing method in clinical practice.
Adult ; Betacoronavirus ; isolation & purification ; C-Reactive Protein ; analysis ; China ; Coronavirus Infections ; diagnosis ; physiopathology ; Diarrhea ; virology ; Feces ; virology ; Female ; Ferritins ; analysis ; Humans ; Leukocyte Count ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral ; diagnosis ; physiopathology ; Retrospective Studies

OBJECTIVES: To analyze the clinical characteristics in patients of coronavirus disease 2019 (COVID-19) complicated with liver injury, to explore the relationship between COVID-19 clinical classification and liver injury, and to elucidate whether COVID-19 complicated with hepatitis B virus can aggravate liver injury. METHODS: The abnormal liver function in 110 patients in the First Hospital of Changsha, who were confirmed COVID-19 and admitted to the designated hospital from January 17, 2020 to February 20, 2020, wereretrospectively analyzed. The detection indexes included serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB), and total bilirubin (TBIL). RESULTS: A total of 49.1% of the COVID-19 patients had liver injury. There were significant difference in the ALT, AST, ALB (all <0.05), but there was no significant difference in the TBIL (>0.05) between the severe (critical) patients and the general (light) patients. There was also no significant difference in the liver function injury between the HBsAg-positive COVID-19 patients and HBsAg-negative COVID-19 patients (>0.05). Acute liver injury was not found to be a direct cause of death in the patients. CONCLUSIONS In the COVID-19 patients, the incidence of liver injury is high with the increase of ALT and AST and the decrease of ALB. Severe and critical patients have obvious liver injury, and those patients complicated with hepatitis B virus infection don't show aggravated liver injury.
Alanine Transaminase ; blood ; Aspartate Aminotransferases ; blood ; Betacoronavirus ; Bilirubin ; blood ; Coronavirus Infections ; diagnosis ; Humans ; Liver ; physiopathology ; virology ; Liver Diseases ; virology ; Pandemics ; Pneumonia, Viral ; diagnosis ; Serum Albumin, Human ; analysis