A comprehensive overview on the transmission, pathogenesis, diagnosis, treatment, and prevention of SARS-CoV-2.

Severe acute respiratory syndrome coronavirus (SARS-CoV) is a single positive-strand RNA virus that is responsible for the current pandemic that the world has been facing since 2019. The primary route of transmission of SARS-CoV-2 is through respiratory tract transmission. However, other transmission routes such as fecal-oral, vertical transmission, and aerosol-eye also exist. In addition, it has been found that the pathogenesis of this virus involves the binding of the virus's S protein to its host cell surface receptor angiotensin-converting enzyme 2, which results in the subsequent membrane fusion that is required for SARS-CoV-2 to replicate and complete its entire life. The clinical symptoms of patients infected with SARS-CoV-2 can range from asymptomatic to severe. The most common symptoms seen include fever, dry cough, and fatigue. Once these symptoms are observed, a nucleic acid test is done using reverse transcription-polymerase chain reaction. This currently serves as the main confirmatory tool for COVID-19. Despite the fact that no cure has been found for SARS-CoV-2, prevention methods such as vaccines, specific facial mask, and social distancing have proven to be quite effective. It is imperative to have a complete understanding of the transmission and pathogenesis of this virus. To effectively develop new drugs as well as diagnostic tools, more knowledge about this virus would be needed.

A retrospective study of Pupingqinghua prescription versus Lianhuaqingwen in Chinese participants infected with SARS-CoV-2 Omicron variants.

Background: Coronavirus disease (COVID-19) seriously endangers global public health. Pupingqinghua prescription (PPQH) is an herbal formula from traditional Chinese medicine used for treatment of SARS-CoV-2 infection. This study aims to evaluate the clinical efficacy and safety of PPQH in Chinese participants infected with the SARS-CoV-2 Omicron variant. Methods: A total of 873 SARS-CoV-2 (Omicron)-infected patients were included. Among them, the patients were divided into the PPQH group (653 cases) and LHQW group (220 cases) according to different medications. The effectiveness indicators (hematological indicators, Ct values of novel Coronavirus nucleic acid tests, and viral load-shedding time) and safety indicators (liver and kidney function and adverse events) were analyzed. Results: There was no significant difference in baseline characteristics between the PPQH group and the LHQW group, except the gender; After the treatment, the levels of IL-5, IL-6, IL-10, NK cells, and INF-α of the patients in the PPQH group showed a downward trend (p < 0.05); The viral load shedding time was 5.0 (5.0, 7.0) in the PPQH group and 5.0 (4.0, 7.0) in the LHQW group; both PPQH and LHQW can shorten the duration of symptoms of fever, cough, and sore throat. The re-positive rate of COVID-19 test was 1.5 % in the PPQH group and 2.3 % in the LHQW group. In terms of safety, the levels of γ-GTT decreased significantly (p < 0.01); gastrointestinal reaction was the primary adverse reaction, and the reaction rate was 4.7 % in the PPQH group and 9.5 % in the LHQW group. Conclusion: PPQH can shorten the length of hospital stay and improve clinical symptoms of patients with SARS-COV-2 (Omicron), and it also has a good safety profile.

A retrospective study of Pupingqinghua prescription versus Lianhuaqingwen in Chinese participants infected with SARS-CoV-2 Omicron variants

Background: Coronavirus disease (COVID-19) seriously endangers global public health. Pupingqinghua prescription (PPQH) is an herbal formula from traditional Chinese medicine used for treatment of SARS-CoV-2 infection. This study aims to evaluate the clinical efficacy and safety of PPQH in Chinese participants infected with the SARS-CoV-2 Omicron variant. Methods: A total of 873 SARS-CoV-2 (Omicron)-infected patients were included. Among them, the patients were divided into the PPQH group (653 cases) and LHQW group (220 cases) according to different medications. The effectiveness indicators (hematological indicators, Ct values of novel Coronavirus nucleic acid tests, and viral load-shedding time) and safety indicators (liver and kidney function and adverse events) were analyzed. Results: There was no significant difference in baseline characteristics between the PPQH group and the LHQW group, except the gender;After the treatment, the levels of IL-5, IL-6, IL-10, NK cells, and INF-α of the patients in the PPQH group showed a downward trend (p < 0.05);The viral load shedding time was 5.0 (5.0, 7.0) in the PPQH group and 5.0 (4.0, 7.0) in the LHQW group;both PPQH and LHQW can shorten the duration of symptoms of fever, cough, and sore throat. The re-positive rate of COVID-19 test was 1.5 % in the PPQH group and 2.3 % in the LHQW group. In terms of safety, the levels of γ-GTT decreased significantly (p < 0.01);gastrointestinal reaction was the primary adverse reaction, and the reaction rate was 4.7 % in the PPQH group and 9.5 % in the LHQW group. Conclusion: PPQH can shorten the length of hospital stay and improve clinical symptoms of patients with SARS-COV-2 (Omicron), and it also has a good safety profile.

Construction and Application of in vitro Alveolar Models Based on 3D Printing Technology

Increasing lung diseases, mutating coronaviruses, and the development of new compounds urgently require biomimetic in vitro lung models for lung pathology, toxicology, and pharmacology. The current construction strategies for lung models mainly include animal models, 2D cell culture, lung-on-a-chip, and lung organoids. However, current models face difficulties in reproducing in vivo-like alveolar size and vesicle-like structures, and are unable to contain multiple cell types. In this study, a strategy for constructing alveolar models based on degradable hydrogel microspheres is proposed. Hydrogel microspheres, 200–250 μm in diameter, were prepared using a self-developed printing technique driven by alternating viscous and inertial forces. Microcapsules were further constructed using a coacervation-based layer-by-layer technique and core liquefaction. Three types of cells were inoculated and co-cultured on hydrogel capsules based on optimized microcapsule surface treatment strategies. Finally, an in vitro three-dimensional endothelial alveolar model with a multicellular composition and vesicle-like structure with a diameter of approximately 230 μm was successfully constructed. Cells in the constructed alveolar model maintained a high survival rate. The LD50 values of glutaraldehyde based on the constructed models were in good agreement with the reference values, validating the potential of the model for future toxicant and drug detection.

Respiratory Mucosal Immunity: Kinetics of Secretory Immunoglobulin A in Sputum and Throat Swabs From COVID-19 Patients and Vaccine Recipients.

While IgM and IgG response to SARS-CoV-2 has been extensively studied, relatively little is known about secretory IgA (sIgA) response in respiratory mucosa. Here we report IgA response to the SARS-CoV-2 in sputum, throat swabs, and serum with nucleocapsid protein (NP) enzyme-linked immunosorbent assays (ELISA) in a cohort of 28 COVID-19 patients and 55 vaccine recipients. The assays showed sIgA in respiratory mucosa could be detected on the first day after illness onset (AIO), and the median conversion time for sIgA in sputum, throat swabs, and serum was 3, 4, and 10 days, respectively. The positive rates of sIgA first week AIO were 100% (24/28) and 85.7% (24/28) in sputum and throat swabs, respectively, and were both 100% during the mid-onset (2-3 weeks AIO). During the recovery period, sIgA positive rates in sputum and throat swabs gradually decreased from 60.7% (17/28) and 57.1% (16/28) 1 month AIO and the sIgA antibodies were all undetectable 6 months AIO. However, serum IgA positive rate was still 100% at 4 months and 53.6% (15/28) at 6 months. Throat swabs obtained from volunteers who received inactivated SARS-CoV-2 vaccines by intramuscular delivery all showed negative results in IgA ELISA. These findings will likely improve our understanding of respiratory mucosal immunity of this emerging disease and help in containing the pandemic and developing vaccines.

A Review of SARS-CoV2: Compared With SARS-CoV and MERS-CoV.

The outbreak of coronavirus disease 2019 (COVID-19) has been spreading rapidly in China and the Chinese government took a series of policies to control the epidemic. Studies found that severe COVID-19 is characterized by pneumonia, lymphopenia, exhausted lymphocytes and a cytokine storm. Studies have showen that SARS-CoV2 has significant genomic similarity to the severe acute respiratory syndrome (SARS-CoV), which was a pandemic in 2002. More importantly, some diligent measures were used to limit its spread according to the evidence of hospital spread. Therefore, the Public Health Emergency of International Concern (PHEIC) has been established by the World Health Organization (WHO) with strategic objectives for public health to curtail its impact on global health and economy. The purpose of this paper is to review the transmission patterns of the three pneumonia: SARS-CoV2, SARS-CoV, and MERS-CoV. We compare the new characteristics of COVID-19 with those of SARS-CoV and MERS-CoV.

Coronary artery calcification and risk of mortality and adverse outcomes in patients with COVID-19: a Chinese multicenter retrospective cohort study.

Background: Coronary artery calcification (CAC) is an independent risk factor of major adverse cardiovascular events; however, the impact of CAC on in-hospital death and adverse clinical outcomes in patients with coronavirus disease 2019 (COVID-19) remains unclear. Objective: To explore the association between CAC and in-hospital mortality and adverse events in patients with COVID-19. Methods: This multicenter retrospective cohort study enrolled 2067 laboratory-confirmed COVID-19 patients with definitive clinical outcomes (death or discharge) admitted from 22 tertiary hospitals in China between January 3, 2020 and April 2, 2020. Demographic, clinical, laboratory results, chest CT findings, and CAC on admission were collected. The primary outcome was in-hospital death and the secondary outcome was composed of in-hospital death, admission to intensive care unit (ICU), and requiring mechanical ventilation. Multivariable Cox regression analysis and Kaplan-Meier plots were used to explore the association between CAC and in-hospital death and adverse clinical outcomes. Results: The mean age was 50 years (SD,16) and 1097 (53.1%) were male. A total of 177 patients showed high CAC level, and compared with patients with low CAC, these patients were older (mean age: 49 vs. 69 years, P < 0.001) and more likely to be male (52.0% vs. 65.0%, P = 0.001). Comorbidities, including cardiovascular disease (CVD) ([33.3%, 59/177] vs. [4.7%, 89/1890], P < 0.001), presented more often among patients with high CAC, compared with patients with low CAC. As for laboratory results, patients with high CAC had higher rates of increased D-dimer, LDH, as well as CK-MB (all P < 0.05). The mean CT severity score in high CAC group was also higher than low CAC group (12.6 vs. 11.1, P = 0.005). In multivariable Cox regression model, patients with high CAC were at a higher risk of in-hospital death (hazard ratio [HR], 1.731; 95% CI 1.010-2.971, P = 0.046) and adverse clinical outcomes (HR, 1.611; 95% CL 1.087-2.387, P = 0.018). Conclusion: High CAC is a risk factor associated with in-hospital death and adverse clinical outcomes in patients with confirmed COVID-19, which highlights the importance of calcium load testing for hospitalized COVID-19 patients and calls for attention to patients with high CAC. Supplementary Information: The online version contains supplementary material available at 10.1007/s42058-021-00072-4.

Evaluation of serum IgM and IgG antibodies in COVID-19 patients by enzyme linked immunosorbent assay.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is sweeping the world since the end of 2019. The titer change of antibodies against SARS-CoV-2 needs to be further clarified, the clinical and preventive value of antibodies still needs to be further investigated. An enzyme-linked immunosorbent assay (ELISA) was established by coating with SARS-CoV-2 recombinant spike protein and used to detect serum immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against SARS-CoV-2 in coronavirus disease 2019 patients to evaluate the pattern of changes of antibodies. The specificity of the ELISA for detection SARS-CoV-2 IgM and IgG were 96% (144/150) and 100% (150/150), respectively. The sensitivity of ELISA was 100% (150/150) for IgM, and 99.3% (149/150) for IgG. SARS-CoV-2-SP-IgM and SP-IgG antibodies could be detected on Day 1 of hospitalization in 12.5% patients, and SP-IgM began to decrease after reaching its peak at around 22-28 days, and become negative at Month 3 in 30% patients and negative at Month 7 in 79% of these patients after onset; IgG reached its peak around Day 22-28 and kept at a high level within the longest observation period for 4 months, it dropped very sharply at 7 months. The positive rates of SP-IgM and SP-IgG were higher than those of reverse transcription-polymerase chain reaction on Day 7 and 4. The established indirect ELISA has good specificity and sensitivity. IgM and IgG against SARS-CoV-2 appeared almost simultaneously in the early stage, and the level of IgG antibodies could not maintain a high plateau in the observation period of 7 months. Our data will help develop the diagnosis and vaccine of SARS-CoV-2.

Spontaneous pneumomediastinum in an elderly COVID-19 patient: A case report.

BACKGROUND: Spontaneous pneumomediastinum (SPM) is more common in young adults, usually caused by external factors like trauma. It causes symptoms such as chest pain or dyspnea, but it is rare to see elderly patients who develop SPM. Here we report the case of an elderly patient diagnosed with coronavirus disease 2019 (COVID-19) who neither got mechanical ventilation nor had chest trauma but were found to develop SPM for unknown reason. CASE SUMMARY: A 62-year-old man complained of a 14-d history of fever accompanied by dry cough, shortness of breath, wheezing, myalgia, nausea, and vomiting. Real-time fluorescence polymerase chain reaction confirmed the diagnosis of COVID-19. The patient was treated with supplementary oxygen by nasal cannula and gamma globulin. Other symptomatic treatments included antibacterial and antiviral treatments. On day 4 of hospitalization, he reported sudden onset of dyspnea. On day 6, he was somnolent. On day 12, the patient reported worsening right-sided chest pain which eventually progressed to bilateral chest pain. He was diagnosed with SPM, with no clear trigger found. Conservative treatment was administrated. During follow-up, the pneumomediastinum had resolved and the patient recovered without other complications. CONCLUSION: We presume that aging lung changes and bronchopulmonary infection play an important part in the onset of SPM in COVID-19, but severe acute respiratory syndrome may represent a separate pathophysiologic mechanism for pneumomediastinum. Although the incidence of SPM in elderly patients is low, clinicians should be alert to the possibility of SPM in those infected with severe acute respiratory syndrome coronavirus 2 for life-threatening complications such as cardiorespiratory arrest may occur.

Risk factors for adverse clinical outcomes with COVID-19 in China: a multicenter, retrospective, observational study.

Background: The risk factors for adverse events of Coronavirus Disease-19 (COVID-19) have not been well described. We aimed to explore the predictive value of clinical, laboratory and CT imaging characteristics on admission for short-term outcomes of COVID-19 patients. Methods: This multicenter, retrospective, observation study enrolled 703 laboratory-confirmed COVID-19 patients admitted to 16 tertiary hospitals from 8 provinces in China between January 10, 2020 and March 13, 2020. Demographic, clinical, laboratory data, CT imaging findings on admission and clinical outcomes were collected and compared. The primary endpoint was in-hospital death, the secondary endpoints were composite clinical adverse outcomes including in-hospital death, admission to intensive care unit (ICU) and requiring invasive mechanical ventilation support (IMV). Multivariable Cox regression, Kaplan-Meier plots and log-rank test were used to explore risk factors related to in-hospital death and in-hospital adverse outcomes. Results: Of 703 patients, 55 (8%) developed adverse outcomes (including 33 deceased), 648 (92%) discharged without any adverse outcome. Multivariable regression analysis showed risk factors associated with in-hospital death included ≥ 2 comorbidities (hazard ratio [HR], 6.734; 95% CI; 3.239-14.003, p < 0.001), leukocytosis (HR, 9.639; 95% CI, 4.572-20.321, p < 0.001), lymphopenia (HR, 4.579; 95% CI, 1.334-15.715, p = 0.016) and CT severity score > 14 (HR, 2.915; 95% CI, 1.376-6.177, p = 0.005) on admission, while older age (HR, 2.231; 95% CI, 1.124-4.427, p = 0.022), ≥ 2 comorbidities (HR, 4.778; 95% CI; 2.451-9.315, p < 0.001), leukocytosis (HR, 6.349; 95% CI; 3.330-12.108, p < 0.001), lymphopenia (HR, 3.014; 95% CI; 1.356-6.697, p = 0.007) and CT severity score > 14 (HR, 1.946; 95% CI; 1.095-3.459, p = 0.023) were associated with increased odds of composite adverse outcomes. Conclusion: The risk factors of older age, multiple comorbidities, leukocytosis, lymphopenia and higher CT severity score could help clinicians identify patients with potential adverse events.