Genetic Characterization and Evolution of Porcine Deltacoronavirus Isolated in the Republic of Korea in 2022.

Porcine deltacoronavirus (PDCoV) is an emerging coronavirus that causes diarrhea in nursing piglets. Since its first outbreak in the United States in 2014, this novel porcine coronavirus has been detected worldwide, including in Korea. However, no PDCoV case has been reported since the last report in 2016 in Korea. In June 2022, the Korean PDCoV strain KPDCoV-2201 was detected on a farm where sows and piglets had black tarry and watery diarrhea, respectively. We isolated the KPDCoV-2201 strain from the intestinal samples of piglets and sequenced the viral genome. Genetically, the full-length genome and spike gene of KPDCoV-2201 shared 96.9-99.2% and 95.8-98.8% nucleotide identity with other global PDCoV strains, respectively. Phylogenetic analysis suggested that KPDCoV-2201 belongs to G1b. Notably, the molecular evolutionary analysis indicated that KPDCoV-2201 evolved from a clade different from that of previously reported Korean PDCoV strains and is closely related to the emergent Peruvian and Taiwanese PDCoV strains. Furthermore, KPDCoV-2201 had one unique and two Taiwanese strain-like amino acid substitutions in the receptor-binding domain of the S1 region. Our findings suggest the possibility of transboundary transmission of the virus and expand our knowledge about the genetic diversity and evolution of PDCoV in Korea.

Corrigendum: Evolution, ecology, and zoonotic transmission of betacoronaviruses: a review.

[This corrects the article DOI: 10.3389/fvets.2021.644414.].

The coronavirus recombination pathway.

Recombination is thought to be a mechanism that facilitates cross-species transmission in coronaviruses, thus acting as a driver of coronavirus spillover and emergence. Despite its significance, the mechanism of recombination is poorly understood, limiting our potential to estimate the risk of novel recombinant coronaviruses emerging in the future. As a tool for understanding recombination, here, we outline a framework of the recombination pathway for coronaviruses. We review existing literature on coronavirus recombination, including comparisons of naturally observed recombinant genomes as well as in vitro experiments, and place the findings into the recombination pathway framework. We highlight gaps in our understanding of coronavirus recombination illustrated by the framework and outline how further experimental research is critical for disentangling the molecular mechanism of recombination from external environmental pressures. Finally, we describe how an increased understanding of the mechanism of recombination can inform pandemic predictive intelligence, with a retrospective emphasis on SARS-CoV-2.

Persistent Exhausted T-Cell Immunity after Severe COVID-19: 6-Month Evaluation in a Prospective Observational Study.

INTRODUCTION: Severe COVID-19 can result in a significant and irreversible impact on long-term recovery and subsequent immune protection. Understanding the complex immune reactions may be useful for establishing clinically relevant monitoring. METHODS: Hospitalized adults with SARS-CoV-2 between March/October 2020 (n = 64) were selected. Cryopreserved peripheral blood mononuclear cells (PBMCs) and plasma samples were obtained at hospitalization (baseline) and 6 months after recovery. Immunological components' phenotyping and SARS-CoV-2-specific T-cell response were studied in PBMCs by flow cytometry. Up to 25 plasma pro/anti-inflammatory cytokines/chemokines were assessed by LEGENDplex immunoassays. The SARS-CoV-2 group was compared to matched healthy donors. RESULTS: Biochemical altered parameters during infection were normalized at a follow-up time point in the SARS-CoV-2 group. Most of the cytokine/chemokine levels were increased at baseline in the SARS-CoV-2 group. This group showed increased Natural Killer cells (NK) activation and decreased CD16high NK subset, which normalized six months later. They also presented a higher intermediate and patrolling monocyte proportion at baseline. T cells showed an increased terminally differentiated (TemRA) and effector memory (EM) subsets distribution in the SARS-CoV-2 group at baseline and continued to increase six months later. Interestingly, T-cell activation (CD38) in this group decreased at the follow-up time point, contrary to exhaustion markers (TIM3/PD1). In addition, we observed the highest SARS-CoV-2-specific T-cell magnitude response in TemRA CD4 T-cell and EM CD8 T-cell subsets at the six-months time point. CONCLUSIONS: The immunological activation in the SARS-CoV-2 group during hospitalization is reversed at the follow-up time point. However, the marked exhaustion pattern remains over time. This dysregulation could constitute a risk factor for reinfection and the development of other pathologies. Additionally, high SARS-CoV-2-specific T-cells response levels appear to be associated with infection severity.

The Mutational Landscape of SARS-CoV-2.

Mutation research is crucial for detecting and treating SARS-CoV-2 and developing vaccines. Using over 5,300,000 sequences from SARS-CoV-2 genomes and custom Python programs, we analyzed the mutational landscape of SARS-CoV-2. Although almost every nucleotide in the SARS-CoV-2 genome has mutated at some time, the substantial differences in the frequency and regularity of mutations warrant further examination. C>U mutations are the most common. They are found in the largest number of variants, pangolin lineages, and countries, which indicates that they are a driving force behind the evolution of SARS-CoV-2. Not all SARS-CoV-2 genes have mutated in the same way. Fewer non-synonymous single nucleotide variations are found in genes that encode proteins with a critical role in virus replication than in genes with ancillary roles. Some genes, such as spike (S) and nucleocapsid (N), show more non-synonymous mutations than others. Although the prevalence of mutations in the target regions of COVID-19 diagnostic RT-qPCR tests is generally low, in some cases, such as for some primers that bind to the N gene, it is significant. Therefore, ongoing monitoring of SARS-CoV-2 mutations is crucial. The SARS-CoV-2 Mutation Portal provides access to a database of SARS-CoV-2 mutations.

Regional Differences, Dynamic Evolution and Convergence of Public Health Level in China.

People's health is a necessary condition for the country's prosperity. Under the background of the COVID-19 pandemic and frequent natural disasters, exploring the spatial and temporal distribution, regional differences and convergence of China's provincial public health level is of great significance to promoting the coordinated development of China's regional public health and achieving the strategic goal of a "healthy China". Based on China's provincial panel data from 2009 to 2020, this paper constructs an evaluation index system for China's public health level from five dimensions: the popularization of a healthy life, optimization of health services, improvement of health insurance, construction of a healthy environment, and development of a health industry. In this paper, the entropy method, Dagum Gini coefficient, Kernel density function and spatial econometric model are used to analyze the spatiotemporal distribution, regional differences, dynamic evolution and convergence of China's public health level since the new medical reform. The study found that, first, China's public health level is generally low, structural contradictions are prominent and the construction of a healthy environment has become a shortcoming hindering the improvement of China's public health level since the new medical reform. The public health level of the four major regions showed a spatial distribution pattern of "high in the eastern, low in the northeastern, central and western" areas. Second, the overall Gini coefficient of China's public health level showed a "V-shaped" trend of first decreasing and then rising, but the overall decrease was greater than the increase, among which the regional difference was the main source of regional differences in China's public health level, but its contribution rate showed a downward trend. Third, except for the basic maintenance of a healthy environment, the Kernel density curves of China's public health level and its sub-dimensions have shifted to the right to a certain extent, and there is no polarization phenomenon. Finally, the level of public health in China has a significant spatial correlation. Except for the northeast region, the growth rate of low-level public health provinces in China and the other three major regions is higher than that of high-level public health provinces, showing a certain convergence trend. In addition, the impact of economic development, financial pressure, and urbanization on the convergence of public health levels in the four major regions is significantly heterogeneous.

Molecular detection of monkeypox and related viruses: challenges and opportunities.

The recent widespread emergence of monkeypox (mpox), a rare and endemic zoonotic disease by monkeypox virus (MPXV), has made global headlines. While transmissibility (R0 ≈ 0.58) and fatality rate (0-3%) are low, as it causes prolonged morbidity, the World Health Organization has declared monkeypox as a public health emergency of international concern. Thus, effective containment and disease management require quick and efficient detection of MPXV. In this bioinformatic overview, we summarize the numerous molecular tests available for MPXV, and discuss the diversity of genes and primers used in the polymerase chain reaction-based detection. Over 90 primer/probe sets are used for the detection of poxviruses. While hemagglutinin and A-type inclusion protein are the most common target genes, tumor necrosis factor receptor and complement binding protein genes are frequently used for distinguishing Clade I and Clade II of MPXV. Problems and possibilities in the detection of MPXV have been discussed.

Identification of Evolutionary Trajectories Shared across Human Betacoronaviruses.

Comparing the evolution of distantly related viruses can provide insights into common adaptive processes related to shared ecological niches. Phylogenetic approaches, coupled with other molecular evolution tools, can help identify mutations informative on adaptation, although the structural contextualization of these to functional sites of proteins may help gain insight into their biological properties. Two zoonotic betacoronaviruses capable of sustained human-to-human transmission have caused pandemics in recent times (SARS-CoV-1 and SARS-CoV-2), although a third virus (MERS-CoV) is responsible for sporadic outbreaks linked to animal infections. Moreover, two other betacoronaviruses have circulated endemically in humans for decades (HKU1 and OC43). To search for evidence of adaptive convergence between established and emerging betacoronaviruses capable of sustained human-to-human transmission (HKU1, OC43, SARS-CoV-1, and SARS-CoV-2), we developed a methodological pipeline to classify shared nonsynonymous mutations as putatively denoting homoplasy (repeated mutations that do not share direct common ancestry) or stepwise evolution (sequential mutations leading towards a novel genotype). In parallel, we look for evidence of positive selection and draw upon protein structure data to identify potential biological implications. We find 30 candidate mutations, from which 4 (codon sites 18121 [nsp14/residue 28], 21623 [spike/21], 21635 [spike/25], and 23948 [spike/796]; SARS-CoV-2 genome numbering) further display evolution under positive selection and proximity to functional protein regions. Our findings shed light on potential mechanisms underlying betacoronavirus adaptation to the human host and pinpoint common mutational pathways that may occur during establishment of human endemicity.

Recurrent Loss of Macrodomain Activity in Host Immunity and Viral Proteins.

Protein post-translational modifications (PTMs) are an important battleground in the evolutionary arms races that are waged between the host innate immune system and viruses. One such PTM, ADP-ribosylation, has recently emerged as an important mediator of host antiviral immunity. Important for the host-virus conflict over this PTM is the addition of ADP-ribose by PARP proteins and removal of ADP-ribose by macrodomain-containing proteins. Interestingly, several host proteins, known as macroPARPs, contain macrodomains as well as a PARP domain, and these proteins are both important for the host antiviral immune response and evolving under very strong positive (diversifying) evolutionary selection. In addition, several viruses, including alphaviruses and coronaviruses, encode one or more macrodomains. Despite the presence of the conserved macrodomain fold, the enzymatic activity of many of these proteins has not been characterized. Here, we perform evolutionary and functional analyses to characterize the activity of macroPARP and viral macrodomains. We trace the evolutionary history of macroPARPs in metazoans and show that PARP9 and PARP14 contain a single active macrodomain, whereas PARP15 contains none. Interestingly, we also reveal several independent losses of macrodomain enzymatic activity within mammalian PARP14, including in the bat, ungulate, and carnivore lineages. Similar to macroPARPs, coronaviruses contain up to three macrodomains, with only the first displaying catalytic activity. Intriguingly, we also reveal the recurrent loss of macrodomain activity within the alphavirus group of viruses, including enzymatic loss in insect-specific alphaviruses as well as independent enzymatic losses in two human-infecting viruses. Together, our evolutionary and functional data reveal an unexpected turnover in macrodomain activity in both host antiviral proteins and viral proteins.

Bringing resilience together: On the co-evolutionary capacities of boundary organizations during the COVID-19 pandemic in Rotterdam.

For a city to maintain its vitality during a crisis like the COVID-19 pandemic, social resilience is pivotal. It is a manifestation of adaptive and transformative capacities in a city, through a multitude of interactions between initiatives and organizations, including local government. Resilience can take many forms: coping, adaptive, transformative; community-based, organizational, and institutional. Due to this hybridity and multiplicity, it remains to be seen how all forms of resilience interact and mutually benefit from one another in a city under crisis. Building further in the relational and dynamic dimensions of resilience, we conceptualize these mutual influences as co-evolution and hypothesise that for mutually beneficial co-evolution a city requires boundary organizations, i.e., organizations that facilitate collaboration and information-flow between differently organized societal domains. In our study of the activities of boundary organizations in the Dutch city Rotterdam during the COVID-19 pandemic, we found that boundary organizations were indeed supportive in building social and especially community resilience, but mainly coping and adaptive. Evidence for co-evolutions between various forms of resilience and institutional transformative resilience remained limited. Transformative potential seemed to get lost in procedural translations, was jeopardized by recentralization policies, and seemed only possible on the currents of already ongoing change.

Within-Host Evolution of SARS-CoV-2 in a B-Cell Depleted Patient With Successful Treatment.

Prolonged viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in an immunocompromised host is a challenge as the treatment and infection control for chronic coronavirus disease 2019 infection is not well established and there is a potential risk of new variants emerging. A 48-year-old woman who underwent chemotherapy, including rituximab and steroid, had reactivation of SARS-CoV-2 68 days after the virus was first detected. She successfully recovered after receiving convalescent plasma and intravenous immunoglobulin. Genomic analysis demonstrated that viruses collected from the nasopharyngeal specimens at day 0 and day 68 had 18 different nucleotide mutations, implying within-host evolution after in-depth epidemiologic investigation.

Trajectories of children and adolescents attending a psychiatric emergency unit during the COVID-19 confinements: 2020-2022 longitudinal study.

INTRODUCTION: The prevalence of psychiatric disorders has not shifted widely through the COVID pandemic, except for some specific groups such as young people or women. Our objective is to examine prospectively the evolution of children and adolescents who consulted in a psychiatric emergency service during the COVID-19 confinements. METHOD: We collected prospective clinical information about 296 young people under 18 who visited a tertiary hospital for psychiatric reasons during the confinement periods in Spain. Clinical diagnoses, suicide attempts, hospital admissions, and pharmacological prescriptions were extracted from electronic health records through 2020, 2021, and 2022. Features of those who maintained psychiatric care and those who did not were compared. RESULTS: Three out of four children and adolescents who visited the psychiatric emergency department during the confinements continued psychiatric care at the end of 2022. Those who did not showed better premorbid adjustment at baseline. During follow-up, diagnoses of neurodevelopmental disorders and eating disorders, as well as the dosage of psychotropic drug prescriptions, increased. The diagnoses of major depressive disorder and eating disorder at baseline were associated with attempting suicide during follow-up. Patients with internalizing symptoms were admitted earlier than those with externalizing symptoms but no differences were found in terms of suicide attempts. CONCLUSIONS: The continuity of psychiatric care after an initial emergency visit during the confinements implied greater clinical severity, as reflected by changes in clinical diagnoses and pharmacological regimens. Emergent symptoms of depression or eating disorders after social distancing or isolation could predict subsequent suicidal behavior in young populations.

Key Aspects of Coronavirus Avian Infectious Bronchitis Virus.

Infectious bronchitis virus (IBV) is an enveloped and positive-sense single-stranded RNA virus. IBV was the first coronavirus to be discovered and predominantly causes respiratory disease in commercial poultry worldwide. This review summarizes several important aspects of IBV, including epidemiology, genetic diversity, antigenic diversity, and multiple system disease caused by IBV as well as vaccination and antiviral strategies. Understanding these areas will provide insight into the mechanism of pathogenicity and immunoprotection of IBV and may improve prevention and control strategies for the disease.

Supply Chain Risk Diffusion in Partially Mapping Double-Layer Hypernetworks.

The impact of COVID-19 is global, and uncertain information will affect product quality and worker efficiency in the complex supply chain network, thus bringing risks. Aiming at individual heterogeneity, a partial mapping double-layer hypernetwork model is constructed to study the supply chain risk diffusion under uncertain information. Here, we explore the risk diffusion dynamics, drawing on epidemiology, and establish an SPIR (Susceptible-Potential-Infected-Recovered) model to simulate the risk diffusion process. The node represents the enterprise, and hyperedge represents the cooperation among enterprises. The microscopic Markov chain approach (MMCA) is used to prove the theory. Network dynamic evolution includes two removal strategies: (i) removing aging nodes; (ii) removing key nodes. Using Matlab to simulate the model, we found that it is more conducive to market stability to eliminate outdated enterprises than to control key enterprises during risk diffusion. The risk diffusion scale is related to interlayer mapping. Increasing the upper layer mapping rate to strengthen the efforts of official media to issue authoritative information will reduce the infected enterprise number. Reducing the lower layer mapping rate will reduce the misled enterprise number, thereby weakening the efficiency of risk infection. The model is helpful for understanding the risk diffusion characteristics and the importance of online information, and it has guiding significance for supply chain management.

The evolution of consumers' demand for hotels under the public health crisis: opinion mining from online reviews

This research aims to grasp the evolution of consumer demand and improve the resilience of the hotel industry under the public health crisis (COVID-19). Online reviews of 7,679 hotels in 10 cities were collected from Ctrip, China's major online hotel platform. Then, we applied opinion mining and time evolution to mine the change in consumer demand before, during, and after the COVID-19 pandemic. Findings show that some consumer demands (e.g. epidemic safety) will change during the outbreak period. However, during the nonoutbreak period, users were more concerned about their own check-in experience (e.g. hotel facilities, front desk services). This article provides new ideas for identifying the dynamic value of online reviews. We suggest that businesses focus on ensuring hotel safety during the crisis period. The results contribute essential theoretical and practical significance to the hotel industry's crisis management during public health crises.

Scaling law of COVID-19 cases and city size and its evolution over time

Urban scaling law quantifies the disproportional growth of urban indicators with urban population size, which is one of the simple rules behind the complex urban system. Infectious diseases are closely related to social interactions that intensify in large cities, resulting in a faster speed of transmission in large cities. However, how this scaling relationship varies in an evolving pandemic is rarely investigated and remains unclear. Here, taking the COVID- 19 epidemic in the United States as an example, we collected daily added cases and deaths from January 2020 to June 2022 in more than three thousand counties to explore the scaling law of COVID- 19 cases and city size and its evolution over time. Results show that COVID- 19 cases super- linearly scaled with population size, which means cases increased faster than population size from a small city to a large city, resulting in a higher morbidity rate of COVID- 19 in large cities. Temporally, the scaling exponent that reflects the scaling relationship stabilized at around 1.25 after a fast increase from less than one. The scaling exponent gradually decreased until it was close to one. In comparison, deaths caused by the epidemic did not show a super-linear scaling relationship with population size, which revealed that the fatality rate of COVID-19 in large cities was not higher than that in small or medium-sized cities. The scaling exponent of COVID- 19 deaths shared a similar trend with that of COVID- 19 cases but with a lag in time. We further estimated scaling exponents in each wave of the epidemic, respectively, which experienced the common evolution process of first rising, then stabilizing, and then decreasing. We also analyzed the evolution of scaling exponents over time from regional and provincial perspectives. The northeast, where New York State is located, had the highest scaling exponent, and the scaling exponent of COVID- 19 deaths was higher than that of COVID-19 cases, which indicates that large cities in this region were more prominently affected by the epidemic. This study reveals the size effect of infectious diseases based on the urban scaling law, and the evolution process of scaling exponents over time also promotes the understanding of the urban scaling law. The mechanism behind temporal variations of scaling exponents is worthy of further exploration. © 2023 Science Press. All rights reserved.

Transforming India's Agrarian Society in a Post-COVID World: Prospects and Challenges

The need for change in India's agrarian sector came into sharp focus with the COVID-19 pandemic. This paper traces the imperatives that have shaped the trajectory of the development of the rural economy in post-independence India including the social, cultural and political matrix within which the processes and activities of the rural economy are carried out. It also explores the possibilities of social, cultural and political change based on a perspective that seeks to reconcile the imperatives of unity and social justice with a practical reading of the ground reality in India's villages. The paper suggests reform in social, cultural and political structures and practices at the village level along with economic prescriptions such as increasing the marketability of agricultural produce and creating jobs in the manufacturing sector to absorb workers displaced from the agricultural sector. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

IDENTIFICATION OF FACTORS ASSOCIATED WITH A WORSE OUTCOME -EXITUS- IN PATIENTS WITH RHEUMATOID ARTHRITIS AND SEVERE INFECTION

BackgroundInfections constitute an important and frequent cause of morbidity and mortality in patients with chronic inflammatory and systemic autoimmune rheumatic diseases. In rheumatoid arthritis (RA), this increased risk has been related to the immune system alterations inherent to the disease, the drugs used to control it (corticosteroids, DMARDs and immunosuppressants) and associated comorbidities. Most studies focus on the search for factors associated with the development of infections but do not explore the worst outcome: patient failure.ObjectivesTo identify factors that help to predict an unfavorable outcome (exitus) after a severe infection in patients with rheumatoid arthritis.MethodsThis study was a retrospective case-control study at a single institution over a 10-year period. Patients with a diagnosis of rheumatoid arthritis with hospital admission for infection from January 1, 2010, to December 31, 2019 (pre-pandemic SARS-COV-2) were selected. The main variable was exitus due to the infectious episode. We collected: age, sex, time of evolution of RA, previous treatment and at the time of admission, number of admissions for infection, location of the infection, comorbidities, and other associated serious diseases. The statistics included a descriptive analysis of the different variables (expressed as median and interquartile range -IR- for quantitative variables and percentages for qualitative variables), and the association study using the χ2 test or Fisher's exact test for qualitative variables, and t-student or Mann-Whitney U and Kruskal Wallis for quantitative variables.ResultsWe obtained 152 patients (71.7% female, 28.3% male), with a total of 214 episodes of admission for infection (115 patients with 1 episode (75.7%), 25 (16.4%) with 2 episodes, 6 being the maximum number of episodes recorded). The median age at admission was 77 years, and the median time of RA evolution was 8 years (IR 4-16). The location of the infection responsible for admission was mainly respiratory and urinary. Forty-eight patients died in the episode (31.6% of the sample, 15 males and 33 females, median age 81.5 years (IR 69.5-86.5)). Comparing the patients with unfavorable outcomes (exitus) with the rest, we only found a statistically significant difference in the number of previous admissions (p=0.011), and in the coexistence of some other serious disease (exitus 85.4%, rest 61.5% p=0.003). There were no differences by sex, age, time of RA evolution, drugs, location of the infection, or comorbidities.ConclusionA history of hospital admission due to infection, and having another serious disease, are factors associated with an unfavorable outcome (exitus) in patients with RA admitted for an infectious process.References[1] Listing J, Gerhold K, Zink A. The risk of infections associated with rheumatoid arthritis, with its comorbidity and treatment. Rheumatology 2013;52(1):53-61.[2] George MD, Baker JF, Winthrop K, Hsu JY, Wu Q, Chen L, et al. Risk for serious infection with low-dose glucocorticoids in patients with Rheumatoid Arthritis: A cohort study. Ann Intern Med. 2020;173(11):870-8.[3] Singh JA, Cameron C, Noorbaloochi S, Cullis T, Tucker M, Christensen R, et al. Risk of serious infection in biological treatment of patients with rheumatoid arthritis: A systematic review and meta-analysis. The Lancet. 2015;386(9990):258-65.Acknowledgements:NIL.Disclosure of InterestsNone Declared.

SARS-CoV-2 Vaccine Against Virus: Mission Accomplished!?

Since the beginning of the COVID-19 pandemic in late 2019, SARS-CoV-2 has started to optimize itself. After crossing the species barrier between bats and humans, it has developed mutations in the viral spike protein, in particular at positions 69/70, 452, 501, 614, and 681, that enhance binding to the ACE-2 receptor and entry into host cells, thereby promoting viral transmissibility and pathogenesis. Mutations at positions 417 and 484 have begun to undermine the effectiveness of convalescent plasma, monoclonal antibodies, and currently available vaccines. The targeted and convergent evolution of SARS-CoV-2, which occurred despite the proofreading activity of the exonuclease, has resulted so far in five variants of concern, which have replaced previous strains. This calls for a worldwide surveillance of viral evolution including animal transmission and the development of vaccines responding to escape variants and inducing mucosal immunity. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

Development and application of a multiplex fluorescent quantitative RT-PCR for detection of Porcine epidemic diarrhea virus, porcine coronavirus and porcine acute diarrhea syndrome coronavirus

To develop a multiplex fluorescent quantitative RT-PCR for the detection of porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV) and swine acute diarrhea syndrome coronavirus (SADS-CoV), in this study, specific primers/probes were designed based on the conserved regions of M, M and N gene sequences of PEDV, PDCoV and SADS-CoV, respectively. After optimization of the reaction conditions, a multiplex fluorescent quantitative RT-PCR for PEDV, PDCoV and SADS-CoV was established. The results of specificity assay showed that the method was positive for detection of PEDV, PDCoV and SADS-CoV, and negative for detection of porcine transmissible gastroenteritis virus, porcine rotavirus, porcine reproductive and respiratory syndrome virus, porcine pseudorabies virus, porcine circovirus type 2, porcine parvovirus, classical swine fever virus and foot-and-mouth disease virus. The results of sensitivity assay showed that the detection limit of this method for PEDV, PDCoV, and SADS-CoV plasmids standard was 1.0x101 copies/L, and had a good linear relationship with their Ct values in the range of 101 copies/L to 106 copies/L. The results of repeatability assay showed that the coefficients of variation (CVs) of intra- and inter-assay reproducibility ranged from 0.33% to 2.53%, indicating good repeatability and stability. To evaluate the effects of the developed method, 100 clinical samples collected from different parts of Henan province were used for detection of these three viruses and compared with those of single RT-PCR and standard methods. The results of multiplex fluorescent quantitative RT-PCR showed that the positive rates of PEDV, PDCoV and SADS-CoV were 38% (38/100), 14% (14/100) and 5% (5/100), respectively. There was no mixed infection. The coincidence rate with the standard detection methods of PEDV and PDCoV was 100%, and the sensitivity was higher than that of single RT-PCR. In this study, a specific, sensitive and rapid multiplex fluorescent quantitative RTPCR method was established for the first time, which could be used for the differential detection of PEDV, PDCoV and SADS-CoV, and laid a foundation for the differential diagnosis and control of porcine diarrheal diseases.