Research progress on detection methods of the asymptomatic COVID-19 infected persons

The global pandemic of COVID-19 has brought great harm and challenges to many countries and regions around the world. The majority of COVID-19 patients have typical clinical manifestations, but the number of asymptomatic infections is increasing as COVID-19 research continues and SARS-CoV-2 testing improves. Many asymptomatic COVID-19 patients with no obvious clinical symptoms are able to transmit the virus to others due to the presence of SARS-CoV-2 in their bodies, thus greatly accelerating the worldwide pandemic and posing great difficulty and threat to global epidemic prevention and control. Therefore, early detection and identification of asymptomatic infected persons through various testing methods are effective measures to control the COVID-19 pandemic. This article will provide a brief review of the available methods and techniques for detecting asymptomatic COVID-19 patients.

Resumption of school after lockdown in COVID-19 pandemic: Three case reports.

BACKGROUND: Students in the 9th grade of junior high school in Changsha were under a 75 d lockdown due to the coronavirus disease 2019 (COVID-19) pandemic. After the resumption of school post-lockdown, the 9th grade students in Changsha faced the entrance physical examination test for senior high school. CASE SUMMARY: We report on 3 cases of occult fracture on the same site in adolescents of the same grade since resumption of school after the lockdown from the COVID-19 pandemic. Three students in the 9th grade of junior high school who were facing the physical examination in 2 wk were diagnosed with an occult fracture of the distal femur. CONCLUSION: It is recommended that the students, parents, education providers and policy makers should all pay attention to the physical exercise of students when the resumption of school after lockdown occurs and they should be aware of occult fractures when the adolescents have pain after physical exercise.

[Impact of Coronavirus Disease 2019 on Prognosis and Treatment Strategies in Patients with Hematological Malignancy--Review].

Coronavirus disease 2019 (COVID-19) has spread rapidly worldwide since outbreak in December 2019, and become a global public health crisis. Patients with hematological malignancy concurrently infected with COVID-19 are often associated with severe even fatal complications, due to low basic immune function, high intensity of chemotherapy and radiotherapy, and slow immune reconstruction post hematopoietic stem cell transplantation, and their treatment strategies, such as anti-infective therapy, blood transfusion, and the use of granulocyte colony stimulating factor need to be adjusted. The characteristics of patients, chemotherapy, hematopoietic stem cell transplantation, and other clinical factors may affect the prognosis of patients with hematological malignancy concurrently infected with COVID-19. Herein, the latest research progress is reviewed.

Differential transcriptomic landscapes of multiple organs from SARS-CoV-2 early infected rhesus macaques.

SARS-CoV-2 infection causes complicated clinical manifestations with variable multi-organ injuries, however, the underlying mechanism, in particular immune responses in different organs, remains elusive. In this study, comprehensive transcriptomic alterations of 14 tissues from rhesus macaque infected with SARS-CoV-2 were analyzed. Compared to normal controls, SARS-CoV-2 infection resulted in dysregulation of genes involving diverse functions in various examined tissues/organs, with drastic transcriptomic changes in cerebral cortex and right ventricle. Intriguingly, cerebral cortex exhibited a hyperinflammatory state evidenced by significant upregulation of inflammation response-related genes. Meanwhile, expressions of coagulation, angiogenesis and fibrosis factors were also up-regulated in cerebral cortex. Based on our findings, neuropilin 1 (NRP1), a receptor of SARS-CoV-2, was significantly elevated in cerebral cortex post infection, accompanied by active immune response releasing inflammatory factors and signal transmission among tissues, which enhanced infection of the central nervous system (CNS) in a positive feedback way, leading to viral encephalitis. Overall, our study depicts a multi-tissue/organ transcriptomic landscapes of rhesus macaque with early infection of SARS-CoV-2, and provides important insights into the mechanistic basis for COVID-19-associated clinical complications.

Proinflammatory cytokines are associated with prolonged viral RNA shedding in COVID-19 patients.

Since December 2019, Coronavirus Disease 2019 (COVID-19) has emerged as a global pandemic. We aimed to investigate the clinical characteristics and analyzed the risk factors for prolonged viral RNA shedding. We retrospectively collected data from 112 hospitalized COVID-19 patients in a single center in Wuhan, China. Factors associated with prolonged viral RNA shedding (≥28 days) were investigated. Forty-nine (43.8%) patients had prolonged viral RNA shedding. Patients with prolonged viral shedding were older and had a higher rate of hypertension. Proinflammatory cytokines, including interleukin-2R (IL-2R) and tumor necrosis factor-α (TNF-α), were significantly elevated in patients with prolonged viral shedding. Multivariate analysis revealed that hypertension, older age, lymphopenia and elevated serum IL-2R were independent risk factors for prolonged viral shedding. This comprehensive investigation revealed the distinct characteristics between patients with or without prolonged viral RNA shedding. Hypertension, older age, lymphopenia and high levels of proinflammatory cytokines may be correlated with prolonged viral shedding.

Dynamic profile of RT-PCR findings from 301 COVID-19 patients in Wuhan, China: A descriptive study.

BACKGROUND: With the spread of Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection, its effect on society is amplified. We aimed to describe the viral detection results across different timepoints throughout the disease course. METHODS: A retrospective study of 301 confirmed COVID-19 patients hospitalized at Tongji Hospital in Wuhan, China, were included. Demographic characteristics of the patients were collected. Upper respiratory specimens (throat and/or nasal swabs) were obtained and analyzed by real-time RT-PCR for SARS-CoV-2 infection. Period of viral infection and the contagious stage were analyzed. RESULTS: Of 301 hospitalized COVID-19 patients, the median age was 58 years and 51.2 % were male. The median period between symptoms presence and positive SARS-CoV-2 RT-PCR results was 16 days (IQR, 10-23, N = 301). The median period between symptoms presence and an effective negative SARS-CoV-2 RT-PCR result was 20 days (IQR, 17-24; N = 216). Infected patient ≥65 years old stayed contagious longer (22 days vs 19 days, p = 0.015). Although two consecutive negative results were confirmed in 70 patients, 30 % of them had positive viral test results for the third time. Using specimens from nasal swabs to run the RT-PCR test showed a higher positive rate than using specimens from throat swabs. CONCLUSIONS: This large-scale investigation with 1113 RT-PCR test results from 301 COVID-19 patients showed that the average contagious period of SARS-CoV-2 infected patients was 20 days. Longer observation period and more than 2 series of negative viral test are necessary for patients ≥65 years.