Abstract The clinical characteristics of patients with COVID-19 were analysed to determine the factors influencing the prognosis and virus shedding time to facilitate early detection of disease progression. Logistic regression analysis was used to explore the relationships among prognosis, clinical characteristics and laboratory indexes. The predictive value of this model was assessed with receiver operating characteristic curve analysis, calibration and internal validation. The viral shedding duration was calculated using the Kaplan–Meier method, and the prognostic factors were analysed by univariate log-rank analysis and the Cox proportional hazards model. A retrospective study was carried out with patients with COVID-19 in Tianjin, China. A total of 185 patients were included, 27 (14.59%) of whom were severely ill at the time of discharge and three (1.6%) of whom died. Our findings demonstrate that patients with an advanced age, diabetes, a low PaO2/FiO2 value and delayed treatment should be carefully monitored for disease progression to reduce the incidence of severe disease. Hypoproteinaemia and the fever duration warrant special attention. Timely interventions in symptomatic patients and a time from symptom onset to treatment <4 days can shorten the duration of viral shedding.

Objectives. Viral load is important when evaluating viral transmission potential, involving the use of a polymerase chain reaction (PCR) cycle threshold (Ct) value. We aimed to analyze the PCR Ct values of respiratory tract samples taken from patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant strains to evaluate these strains’ viral dynamics. Methods. This study comprised 361 patients. The Ct values of SARS-CoV-2-related respiratory samples were compared between symptomatic and asymptomatic patients. Results. The median (25th percentile and 75th percentile) nasopharynx and oropharynx SARS-CoV-2 Ct values were 30.5 (24.5–35.0) and 34.5 (30.0–37.0) in the symptomatic group, respectively, and 27.8 (23.4–34.5) and 33.5 (26.0–35.0) in the asymptomatic group, respectively, without significance. In the symptomatic group, subgroup analyses according to age showed the mean nasal Ct value for patients aged >18 years was 29.0 (23.5–34.5), which was significantly lower than that of patients aged 0–4 years and 5–13 years (36.0 (30.5–38.0) and 34.5 (31.0–39.0), respectively). The nasal Ct value for asymptomatic patients aged >18 years was 25.5 (20.9–28.4), which was significantly lower than of patients aged 5–13 years (34.5 (25.6–36.4)). Conclusion. Our findings suggest that the viral loads of asymptomatic and symptomatic patients did not differ significantly. However, adults infected with SARS-CoV-2 had higher nasal viral loads that those of young children.

Background: Developing liquid biopsy technology with higher sensitivity and specificity especially for low-frequency mutations remains crucial. This study demonstrated superior performance of the newly developed digital PCR (dPCR) kit for ctDNA-based EGFR p.T790M detection in metastatic non-small-cell lung cancer (NSCLC) against ARMS-PCR. Methods: This large-scale, multi-centered diagnostic study recruited 1,045 patients including 1,029 patients diagnosed with advanced NSCLC and 16 patients with specific samples between April 1 st 2018 and November 30 th 2019. EGFR p.T790M in plasma samples from mNSCLC patients were tested using dPCR with ADx-ARMS PCR and Cobas ® EGFR Mutation Test V2 as comparator assays to confirm cut-off value 2 Xu et al. The performance of dPCR in detecting ctDNA-EGFR p.T790M