Coronaviruses are a large family of viruses which include viruses that cause the common cold and severe acute respiratory syndrome (SARS) in humans and other diseases in animals. There are considerable genetic diversities within coronaviruses due to their wide rang hosts and their special gene replication and transcription mechanisms. During this process, gene recombinations often occur, resulting in novel subtype or coronavirus emerge constantly. Of note are SARS-like-CoVs and novel HCoV-EMC identified in 2012. This minireview summarized major advances of recently identified coronaviruses, focusing on the genome structures and interspecies jumping mechanism of coronavirus.
Animals ; Coronavirus ; classification ; genetics ; isolation & purification ; Coronavirus Infections ; transmission ; Humans ; Phylogeny

The deltacoronavirus is a new member of the subfamily Coronaviridae of the family Coronaviridae. Deltacoronaviruses can infect birds and mammals. Deltacoronaviruses were detected in early 2007 in Asian leopard cats and Chinese ferret badgers. In 2014, porcine deltacoronavirus (PDCoV) infection spread rapidly in the USA. Moreover, cell culture-adapted PDCoV has been obtained from infected piglets. Animal experiments have confirmed that the isolated PDCoV is highly pathogenic and causes severe diarrhea in piglets. Thus, the PDCoV can be considered to be a good model to study the deltacoronavirus. In this review, we discuss the etiology, epidemiology, pathogenicity, culture, and diagnostic methods of the PDCoV.
Animals ; Coronavirus ; classification ; genetics ; isolation & purification ; Coronavirus Infections ; veterinary ; virology ; Diarrhea ; veterinary ; virology ; Phylogeny ; Swine ; Swine Diseases ; virology

PURPOSE: During the late autumn to winter season (October to December) in the Republic of Korea, respiratory syncytial virus (RSV) is the most common pathogen causing lower respiratory tract infections (LRTIs). Interestingly, in 2014, human coronavirus (HCoV) caused not only upper respiratory infections but also LRTIs more commonly than in other years. Therefore, we sought to determine the epidemiology, clinical characteristics, outcomes, and severity of illnesses associated with HCoV infections at a single center in Korea. MATERIALS AND METHODS: We retrospectively identified patients with positive HCoV respiratory specimens between October 2014 and December 2014 who were admitted to Severance Children’s Hospital at Yonsei University Medical Center for LRTI. Charts of the patients with HCoV infection were reviewed and compared with RSV infection. RESULTS: During the study period, HCoV was the third most common respiratory virus and accounted for 13.7% of infections. Coinfection was detected in 43.8% of children with HCoV. Interestingly, one patient had both HCoV-OC43 and HCoV-NL63. Mild pneumonia was most common (60.4%) with HCoV, and when combined with RSV, resulted in bronchiolitis. Two patients required care in the intensive care unit. However, compared with that of RSV infection, the disease course HCoV was short. CONCLUSION: Infections caused by HCoVs are common, and can cause LRTIs. During an epidemic season, clinicians should be given special consideration thereto. When combined with other medical conditions, such as neurologic or cardiologic diseases, intensive care unit (ICU) care may be necessary.
Child ; Child, Preschool ; Coronavirus/*isolation & purification ; Coronavirus Infections/epidemiology/*virology ; Coronavirus OC43, Human/isolation & purification ; Female ; Hospitalization ; Humans ; Infant ; Male ; Republic of Korea/epidemiology ; Respiratory Tract Infections/epidemiology/*virology ; Retrospective Studies ; Seasons

Acute respiratory failure due to acute hypoxemia is the major manifestation in severe coronavirus disease 2019 (COVID-19). Rational and effective respiratory support is crucial in the management of COVID-19 patients. High-flow nasal cannula (HFNC) has been utilized widely due to its superiority over other non-invasive respiratory support techniques. To avoid HFNC failure and intubation delay, the key issues are proper patients, timely application and improving compliance. It should be noted that elder patients are vulnerable for failed HFNC. We applied HFNC for oxygen therapy in severe and critical ill COVID-19 patients and summarized the following experiences. Firstly, to select the proper size of nasal catheter, to locate it at suitable place, and to confirm the nose and the upper respiratory airway unobstructed. Secondly, an initial ow of 60 L/min and 37℃ should be given immediately for patients with obvious respiratory distress or weak cough ability; otherwise, low-level support should be given first and the level gradually increased. Thirdly, to avoid hypoxia or hypoxemia, the treatment goal of HFNC should be maintained the oxygen saturation (SpO) above 95% for patients without chronic pulmonary disease. Finally, patients should wear a surgical mask during HFNC treatment to reduce the risk of virus transmission through droplets or aerosols.
Aged ; Betacoronavirus ; isolation & purification ; Cannula ; Coronavirus Infections ; therapy ; Humans ; Oxygen ; administration & dosage ; Pandemics ; Pneumonia, Viral ; therapy

OBJECTIVE: To establish a SEIR epidemic dynamics model that can be used to evaluate the COVID-19 epidemic, and to predict and evaluate the COVID-19 epidemic in Hubei province using the proposed model. METHODS: COVID-19 SEIR transmission dynamics model was established, which took transmission ability in latent period and tracking quarantine interventions into consideration. Based on the epidemic data of Hubei province from January 23, 2020 to February 24, 2020, the parameters of the newly established modified SEIR model were fitted. By using Euler integral algorithm to solve the modified SEIR dynamics model, the epidemic situation in Hubei province was analyzed, and the impact of prevention and control measures such as quarantine and centralized treatment on the epidemic development was discussed. RESULTS: The theoretical estimation of the epidemic situation by the modified SEIR epidemic dynamics model is in good agreement with the actual situation in Hubei province. Theoretical analysis showed that prevention and control quarantine and medical follow-up quarantine played an important inhibitory effect on the outbreak of the epidemic.The centralized treatment played a key role in the rapid decline in the number of infected people. In addition, it is suggested that individuals should improve their prevention awareness and take strict self-protection measures to curb the increase in infected people. CONCLUSIONS The modified SEIR model is reliable in the evaluation of COVID-19 epidemic in Hubei province, which provides a theoretical reference for the decision-making of epidemic interventions.
Algorithms ; Betacoronavirus ; isolation & purification ; China ; epidemiology ; Coronavirus Infections ; epidemiology ; Humans ; Models, Biological ; Pandemics ; Pneumonia, Viral ; epidemiology

No abstract available.
Coronavirus Infections/*diagnosis/virology ; Humans ; Middle East Respiratory Syndrome Coronavirus/genetics/isolation & purification ; Nasopharynx/virology ; RNA, Viral/genetics/metabolism ; Real-Time Polymerase Chain Reaction ; Viral Envelope Proteins/genetics

Since the first imported case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection was reported on May 20, 2015 in Korea, there have been 186 laboratory-confirmed cases of MERS-CoV infection with 36 fatalities. Ninety-seven percent (181/186) of the cases had exposure to the health care facilities. We are reporting a superspreading event that transmitted MERS-CoV to 81 persons at a hospital emergency room (ER) during the Korean outbreak in 2015. The index case was a 35-yr-old man who had vigorous coughing while staying at the ER for 58 hr. As in severe acute respiratory syndrome outbreaks, superspreading events can cause a large outbreak of MERS in healthcare facilities with severe consequences. All healthcare facilities should establish and implement infection prevention and control measure as well as triage policies and procedures for early detection and isolation of suspected MERS-CoV cases.
Adult ; Coronavirus Infections/*epidemiology/*virology ; Female ; Humans ; Incidence ; Male ; Middle East Respiratory Syndrome Coronavirus/*isolation & purification ; Pandemics/*statistics & numerical data ; Republic of Korea/epidemiology ; Risk Factors

No abstract available.
Aged ; Coronavirus Infections/*epidemiology/*transmission/virology ; *Disease Outbreaks ; Female ; Humans ; Male ; Middle Aged ; Middle East Respiratory Syndrome Coronavirus/*isolation & purification ; Republic of Korea/epidemiology

A simple and sensitive assay for rapid detection of human coronavirus NL63 (HCoV-NL63) was developed by colorimetic reverse transcription loop-mediated isothermal amplification (RT-LAMP). The method employed six specially designed primers that recognized eight distinct regions of the HCoV-NL63 nucleocapsid protein gene for amplification of target sequences under isothermal conditions at 63 degrees C for 1 h Amplification of RT-LAMP was monitored by addition of calcein before amplification. A positive reaction was confirmed by change from light-brown to yellow-green under visual detection. Specificity of the RT-LAMP assay was validated by cross-reaction with different human coronaviruses, norovirus, influenza A virus, and influenza B virus. Sensitivity was evaluated by serial dilution of HCoV-NL63 RNA from 1.6 x 10(9) to 1.6 x 10(1) per reaction. The RT-LAMP assay could achieve 1,600 RNA copies per reaction with high specificity. Hence, our colorimetric RT-LAMP assay could be used for rapid detection of human coronavirus NL63.
Colorimetry ; methods ; Coronavirus Infections ; diagnosis ; virology ; Coronavirus NL63, Human ; genetics ; isolation & purification ; DNA Primers ; genetics ; Humans ; Nucleic Acid Amplification Techniques ; methods ; Reverse Transcription ; Sensitivity and Specificity

A simple, rapid and sensitive colorimetric reverse-transcription loop-mediated isothermal amplification (RT-LAMP) was developed for rapid detection of Middle East respiratory syndrome coronavirus (MERS-CoV). The method employed six primers that recognized sequences of a nucleocapsid gene for amplification of nucleic acids under isothermal conditions at 63 degrees C for 60 min. Products were detected through a LA-320c Loopamp Turbidimeter (real-time RT-LAMP) or visual inspection of color change by pre-addition of Hydroxynaphthol Blue dye (visual RT-LAMP). Specificity of RT-LAMP was validated by detection of several human coronaviruses and common respiratory viruses. MERS-CoV real-time RT-LAMP had a linear correlation (R2) of 0.995 at 10(3)-10(6) copies. The limit of detection of real-time RT-LAMP, visual RT-LAMP and quantitative real-time PCR was 500, 1000 and 100 copies/reaction, respectively. The established RT-LAMP assay was demonstrated to be a rapid screening tool for MERS-CoV infection, and could be suitable in resource-limited clinical sites and for field studies.
Coronavirus Infections ; virology ; DNA Primers ; genetics ; Humans ; Middle East Respiratory Syndrome Coronavirus ; classification ; genetics ; isolation & purification ; Nucleic Acid Amplification Techniques ; methods ; Reverse Transcription