COVID-19 in South Korea.

A novel coronavirus (severe acute respiratory syndrome-CoV-2) that initially originated from Wuhan, China, in December 2019 has already caused a pandemic. While this novel coronavirus disease (COVID-19) frequently induces mild diseases, it has also generated severe diseases among certain populations, including older-aged individuals with underlying diseases, such as cardiovascular disease and diabetes. As of 31 March 2020, a total of 9786 confirmed cases with COVID-19 have been reported in South Korea. South Korea has the highest diagnostic rate for COVID-19, which has been the major contributor in overcoming this outbreak. We are trying to reduce the reproduction number of COVID-19 to less than one and eventually succeed in controlling this outbreak using methods such as contact tracing, quarantine, testing, isolation, social distancing and school closure. This report aimed to describe the current situation of COVID-19 in South Korea and our response to this outbreak.

SARS-CoV-2 viral spike G614 mutation exhibits higher case fatality rate.

AIM: The COVID-19 pandemic is caused by infection with the SARS-CoV-2 virus. The major mutation detected to date in the SARS-CoV-2 viral envelope spike protein, which is responsible for virus attachment to the host and is also the main target for host antibodies, is a mutation of an aspartate (D) at position 614 found frequently in Chinese strains to a glycine (G). We sought to infer health impact of this mutation. RESULT: Increased case fatality rate correlated strongly with the proportion of viruses bearing G614 on a country by country basis. The amino acid at position 614 occurs at an internal protein interface of the viral spike, and the presence of G at this position was calculated to destabilise a specific conformation of the viral spike, within which the key host receptor binding site is more accessible. CONCLUSION: These results imply that G614 is a more pathogenic strain of SARS-CoV-2, which may influence vaccine design. The prevalence of this form of the virus should also be included in epidemiologic models predicting the COVID-19 health burden and fatality over time in specific regions. Physicians should be aware of this characteristic of the virus to anticipate the clinical course of infection.

Host range and structural analysis of bat-origin RshSTT182/200 coronavirus binding to human ACE2 and its animal orthologs.

Bat-origin RshSTT182 and RshSTT200 coronaviruses (CoV) from Rhinolophus shameli in Southeast Asia (Cambodia) share 92.6% whole-genome identity with SARS-CoV-2 and show identical receptor-binding domains (RBDs). In this study, we determined the structure of the RshSTT182/200 receptor binding domain (RBD) in complex with human angiotensin-converting enzyme 2 (hACE2) and identified the key residues that influence receptor binding. The binding of the RshSTT182/200 RBD to ACE2 orthologs from 39 animal species, including 18 bat species, was used to evaluate its host range. The RshSTT182/200 RBD broadly recognized 21 of 39 ACE2 orthologs, although its binding affinities for the orthologs were weaker than those of the RBD of SARS-CoV-2. Furthermore, RshSTT182 pseudovirus could utilize human, fox, and Rhinolophus affinis ACE2 receptors for cell entry. Moreover, we found that SARS-CoV-2 induces cross-neutralizing antibodies against RshSTT182 pseudovirus. Taken together, these findings indicate that RshSTT182/200 can potentially infect susceptible animals, but requires further evolution to obtain strong interspecies transmission abilities like SARS-CoV-2.

Inference from longitudinal laboratory tests characterizes temporal evolution of COVID-19-associated coagulopathy (CAC).

Temporal inference from laboratory testing results and triangulation with clinical outcomes extracted from unstructured electronic health record (EHR) provider notes is integral to advancing precision medicine. Here, we studied 246 SARS-CoV-2 PCR-positive (COVIDpos) patients and propensity-matched 2460 SARS-CoV-2 PCR-negative (COVIDneg) patients subjected to around 700,000 lab tests cumulatively across 194 assays. Compared to COVIDneg patients at the time of diagnostic testing, COVIDpos patients tended to have higher plasma fibrinogen levels and lower platelet counts. However, as the infection evolves, COVIDpos patients distinctively show declining fibrinogen, increasing platelet counts, and lower white blood cell counts. Augmented curation of EHRs suggests that only a minority of COVIDpos patients develop thromboembolism, and rarely, disseminated intravascular coagulopathy (DIC), with patients generally not displaying platelet reductions typical of consumptive coagulopathies. These temporal trends provide fine-grained resolution into COVID-19 associated coagulopathy (CAC) and set the stage for personalizing thromboprophylaxis.

Cancer Patients and Risk of Mortality for COVID-19.

Two recent Lancet and Lancet Oncology papers report that cancer patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have higher mortality rates. Common independent factors associated with increased risk of death were older age, history of smoking status, number of comorbidities, more advanced performance status, and active cancer.

Involvement of the digestive system in covid-19. A review. / Afectación del aparato digestivo en la covid-19. Una revisión sobre el tema.

The SARS-CoV-2 pandemic is leading to high mortality and a global health crisis. The primary involvement is respiratory; however, the virus can also affect other organs, such as the gastrointestinal tract and liver. The most common symptoms are anorexia and diarrhea. In about half of the cases, viral RNA could be detected in the stool, which is another line of transmission and diagnosis. covid19 has a worse prognosis in patients with comorbidities, although there is not enough evidence in case of previous digestive diseases. Digestive endoscopies may give rise to aerosols, which make them techniques with a high risk of infection. Experts and scientific organizations worldwide have developed guidelines for preventive measures. The available evidence on gastrointestinal and hepatic involvement, the impact on patients with previous digestive diseases and operating guidelines for Endoscopy Units during the pandemic are reviewed.

Single-cell landscape of bronchoalveolar immune cells in patients with COVID-19.

Respiratory immune characteristics associated with Coronavirus Disease 2019 (COVID-19) severity are currently unclear. We characterized bronchoalveolar lavage fluid immune cells from patients with varying severity of COVID-19 and from healthy people by using single-cell RNA sequencing. Proinflammatory monocyte-derived macrophages were abundant in the bronchoalveolar lavage fluid from patients with severe COVID-9. Moderate cases were characterized by the presence of highly clonally expanded CD8+ T cells. This atlas of the bronchoalveolar immune microenvironment suggests potential mechanisms underlying pathogenesis and recovery in COVID-19.