Characteristics of the Severe Acute Respiratory Syndrome Coronavirus 2 Omicron BA.2 Subvariant in Jilin, China from March to May 2022

Background and Objectives In the midst of the pandemic, new coronavirus mutants continue to emerge;the most relevant variant worldwide is omicron. Here, patients who recovered from the disease living in Jilin Province were analyzed to identify factors affecting the severity of omicron infection and to provide insights into its spread and early indication. Methods In this study, 311 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were divided into two groups. Data on the patients' demographic characteristics and laboratory tests, including platelet count (PLT), neutrophil count (NE), C-reactive protein (CRP), serum creatinine (SCR), and neutrophil-to-lymphocyte ratio (NLR), were collected. The biomarkers for moderate and severe coronavirus disease 2019 (COVID-19) and factors affecting the incubation period and time to subsequent negative nucleic acid amplification test (NAAT) were also investigated. Results Age, gender, vaccination, hypertension, stroke, chronic obstructive pulmonary disease (COPD)/chronic bronchitis/asthma, and some laboratory tests were statistically different between the two groups. In the receiver operating characteristic (ROC) analysis, PLT and CRP had higher area under the ROC curve values. In the multivariate analysis, age, hypertension, COPD/chronic bronchitis/asthma, and CRP were correlated with moderate and severe COVID-19. Moreover, age was correlated with longer incubation. In the Kaplan-Meier curve analysis, gender (male), CRP, and NLR were associated with longer time to subsequent negative NAAT. Conclusions Older patients with hypertension and lung diseases were likely to have moderate or severe COVID-19, and younger patients might have a shorter incubation. A male patient with high CRP and NLR levels might take more time to turn back negative in the NAAT.

Characteristics of the Severe Acute Respiratory Syndrome Coronavirus 2 Omicron BA.2 Subvariant in Jilin, China from March to May 2022.

Background and Objectives: In the midst of the pandemic, new coronavirus mutants continue to emerge; the most relevant variant worldwide is omicron. Here, patients who recovered from the disease living in Jilin Province were analyzed to identify factors affecting the severity of omicron infection and to provide insights into its spread and early indication. Methods: In this study, 311 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were divided into two groups. Data on the patients' demographic characteristics and laboratory tests, including platelet count (PLT), neutrophil count (NE), C-reactive protein (CRP), serum creatinine (SCR), and neutrophil-to-lymphocyte ratio (NLR), were collected. The biomarkers for moderate and severe coronavirus disease 2019 (COVID-19) and factors affecting the incubation period and time to subsequent negative nucleic acid amplification test (NAAT) were also investigated. Results: Age, gender, vaccination, hypertension, stroke, chronic obstructive pulmonary disease (COPD)/chronic bronchitis/asthma, and some laboratory tests were statistically different between the two groups. In the receiver operating characteristic (ROC) analysis, PLT and CRP had higher area under the ROC curve values. In the multivariate analysis, age, hypertension, COPD/chronic bronchitis/asthma, and CRP were correlated with moderate and severe COVID-19. Moreover, age was correlated with longer incubation. In the Kaplan-Meier curve analysis, gender (male), CRP, and NLR were associated with longer time to subsequent negative NAAT. Conclusions: Older patients with hypertension and lung diseases were likely to have moderate or severe COVID-19, and younger patients might have a shorter incubation. A male patient with high CRP and NLR levels might take more time to turn back negative in the NAAT.

Humanized mice for investigating SARS-CoV-2 lung infection and associated human immune responses.

There is an urgent need for animal models of coronavirus disease 2019 to study immunopathogenesis and test therapeutic intervenes. In this study, we showed that NOD/SCID IL2rg-/- (NSG) mice engrafted with human lung (HL) tissue (NSG-L mice) could be infected efficiently by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and that live virus capable of infecting Vero cells was found in the HL grafts and multiple organs from infected NSG-L mice. RNA-Sequencing identified a series of differentially expressed genes, which are enriched in viral defense responses, chemotaxis, IFN stimulation and pulmonary fibrosis, between HL grafts from infected and control NSG-L mice. Furthermore, when infected with SARS-CoV-2, humanized mice with both human immune system (HIS) and autologous HL grafts (HISL mice) had bodyweight loss and hemorrhage and immune cell infiltration in HL grafts, which were not observed in immunodeficient NSG-L mice, indicating the development of anti-viral immune responses in these mice. In support of this possibility, the infected HISL mice showed bodyweight recovery and lack of detectable live virus at the later time. These results demonstrate that NSG-L and HISL mice are susceptible to SARS-CoV-2 infection, offering a useful in vivo model for studying SARS-CoV-2 infection and the associated immune response and immunopathology, and testing anti-SARS-CoV-2 therapies.

Epidemiological and clinical characteristics of 2019 novel coronavirus disease (COVID-19) in Jilin, China: A descriptive study.

Coronavirus diseases 2019 (COVID-19) has become a global pandemic. To add to the scarce information on this disease, here, we investigated the epidemiological and clinical characteristics of 93 hospitalized patients with COVID-19 in Jilin, China from January 22 to March 15, 2020.We retrospectively investigated the demographic information, recent exposure history, clinical symptoms or signs, comorbidity, chest computed tomographic (CT) scan or X-ray results, laboratory test results, diagnostic classification, treatment, length of hospitalization, complications, and outcomes.Of the 93 patients, 54 were male and 39 female. More than half of these patients had a history of exposure to infected patients. The mean incubation period was 10.4 days in 87 patients, where the data was available. The 5 most common symptoms of illness onset were fever, cough, expectoration, fatigue, and dyspnea. One patient was asymptomatic. The imaging results were abnormal in majority of the patients. Almost one-third of the patients had lymphopenia. All patients received antiviral therapy, 84 patients were treated with antibiotics and 54 received different doses of the hormone for methylprednisolone. In addition, 72 patients used traditional Chinese medicine. Oxygen therapy, high nasal flow oxygen, non-invasive ventilator, invasive ventilator and extracorporeal membrane oxygenation (ECMO) were used symptomatically in different patients. Except 1 patient who died during treatment, all others were discharged.The average incubation time is prolonged in the present analysis, as compared to that in other reports. A few patients symptoms improved but CT exacerbated. Therefore, we suggest that close follow-up observation is still required after discharge.

Digital PCR is a sensitive new technique for SARS-CoV-2 detection in clinical applications.

The global coronavirus disease 2019 (COVID-19) pandemic has posed great challenges in people's daily lives. Highly sensitive laboratory techniques played a critical role in clinical COVID-19 diagnosis and management. In this study the feasibility of using a new digital PCR-based detection assay for clinical COVID-19 diagnosis was investigated by comparing its performance with that of RT-PCR. Clinical patient samples and samples obtained from potentially contaminated environments were analyzed. The study included 10 patients with confirmed COVID-19 diagnoses, 32 validated samples of various types derived from different clinical timepoints and sites, and 148 environmentally derived samples. SARS-CoV-2 nucleic acids were more readily detected in respiratory tract samples (35.0%). In analyses of environmentally derived samples, the positivity rate of air samples was higher than that of surface samples, probably due to differences in virus concentrations. Digital PCR detected SARS-CoV-2 in several samples that had previously been deemed negative, including 3 patient-derived samples and 5 environmentally derived samples. In this study digital PCR exhibited higher sensitivity than conventional RT-PCR, suggesting that it may be a useful new method for clinical SARS-CoV-2 detection. Improvement of SARS-CoV-2 detection would substantially reduce the rates of false-negative COVID-19 test results, in particular those pertaining to asymptomatic carriers.

Clinical characteristics of family-clustered onset of coronavirus disease 2019 in Jilin Province, China.

Eight members of a big family with laboratory-confirmed COVID-19 pneumonia were admitted to First Hospital of Jilin University, Changchun, China, from 28 January to 5 February 2020. The clinical records, laboratory results, and chest computed tomography (CT) scans were retrospectively reviewed. Throat swab samples were positive for severe acute respiratory syndrome coronavirus 2, confirmed by the Center for Disease Control and Prevention of Changchun. All eight patients had fever of different degrees; and 6, 3, and 2 had cough; diarrhea; and sore throat. With disease progression, the percentage of lymphocytes in older patients increased, CT images worsened, and the ratio of lymphocytes increased when images revealed inflammation absorption. Although the CT images showed ground-glass opacities in the youngest patient, his lymphocyte count did not decrease with mild clinical symptoms, and the images showed that inflammation was quickly absorbed. Only the oldest patient developed critical illness. The C reaction protein (CRP) levels of Patient 5 increased significantly, and the rate of decline was the slowest, while his condition was the most severe. The clinical manifestations of COVID-19 in this family cluster varied with contact, age, and underlying disease. Lymphocyte count and quality of chest CT images appeared inversely associated with disease severity. CRP changes may be an indicator of disease severity and prognosis.