Viral dynamics of SARS-CoV-2 in immunocompromised patients

Viral load dynamics in asymptomatic and symptomatic patients during Omicron BA.2 outbreak in Shanghai, China, 2022: A longitudinal cohort study

The SARS-CoV-2 virus, particularly the Omicron BA.2 variant, led to a significant surge in Shanghai, 2022. However, the viral load dynamic in Omicron infections with varying clinical severities remain unclear. This prospective cohort included 48,830 hospitalized coronavirus disease 2019 (COVID-19) patients across three hospitals in Shanghai, China, between 23 March and 15 May, 2022. Systematic nucleic acid testing was performed using RT-PCR Cycle threshold (Ct) value as a proxy of viral load. We analyzed the kinetic characteristics of viral shedding by clinical severity and identified associated risk factors. The study comprised 31.06% asymptomatic cases, 67.66% mild-moderate cases, 1.00% severe cases, 0.29% critical and fatal cases. Upon admission, 57% of patients tested positive, with peak viral load observed at 4 days (median Ct value 27.5), followed by a decrease and an average viral shedding time (VST) of 6.1 days (Interquartile range, 4.0-8.8 days). Although viral load exhibited variation by age and clinical severity, peak Ct values occurred at similar times. Unvaccinated status, age exceeding 60, and comorbidities including hypertension, renal issues kidney dialysis and kidney transplantation, neurological disorders, rheumatism, and psychotic conditions were found to correlate with elevated peak viral load and extended VST. Asymptomatic cases demonstrated a 40% likelihood of contagiousness within 6 days of detection, while mild-moderate and severe cases exhibited post-symptom resolution infectious probabilities of 27% and over 50%, respectively. These findings revealed that the initial Ct values serve as a predictive indicator of severe outcomes. Unvaccinated elderly individuals with particular comorbidities are at high-risk for elevated viral load and prolonged VST.

Omicron SARS-CoV-2 infection management and outcomes in patients with hematologic disease and recipients of cell therapy

Introduction

Scarce real-life data exists for COVID-19 management in hematologic disease (HD) patients in the Omicron era.

Purpose

To assess the current clinical management and outcome of SARS-CoV-2 infection diagnosed, identify the risk factors for severe outcomes according to the HD characteristics and cell therapy procedures in a real-world setting.

Methods

A retrospective observational registry led by the Spanish Transplant Group (GETH-TC) with 692 consecutive patients with HD from December 2021 to May 2023 was analyzed.

Results

Nearly one-third of patients (31%) remained untreated and presented low COVID-19-related mortality (0.9%). Nirmatrelvir/ritonavir was used mainly in mild COVID-19 cases in the outpatient setting (32%) with a low mortality (1%), while treatment with remdesivir was preferentially administered in moderate-to-severe SARS-CoV-2 infection cases during hospitalization (35%) with a mortality rate of 8.6%. The hospital admission rate was 23%, while 18% developed pneumonia. COVID-19-related mortality in admitted patients was 14%. Older age, autologous hematopoietic stem cell transplantation (SCT), chimeric antigen receptor T-cell therapy, corticosteroids and incomplete vaccination were factors independently associated with COVID-19 severity and significantly related with higher rates of hospital admission and pneumonia. Incomplete vaccination status, treatment with prior anti-CD20 monoclonal antibodies, and comorbid cardiomyopathy were identified as independent risk factors for COVID-19 mortality.

Conclusions

The results support that, albeit to a lower extent, COVID-19 in the Omicron era remains a significant problem in HD patients. Complete vaccination (3 doses) should be prioritized in these immunocompromised patients. The identified risk factors may help to improve COVID-19 management to decrease the rate of severe disease, ICU admissions and mortality.

Culturing of SARS-CoV-2 from patient samples: Protocol for optimal virus recovery and assessment of infectious viral load

Optimal sampling, preservation, and culturing of SARS-CoV-2 from COVID-19 patients are critical for successful recovery of virus isolates and to accurately estimate contagiousness of the patient. In this study, we investigated the influence of the type of sampling media, storage time, freezing conditions, sterile filtration, and combinations of these to determine the optimal pre-analytic conditions for virus recovery and estimation of infectious viral load in COVID-19 patients. Further, we investigated the viral shedding kinetics and mucosal antibody response in 38 COVID-19 hospitalized patients. We found Universal Transport Medium (Copan) to be the most optimal medium for preservation of SARS-CoV-2 infectivity. Our data showed that the probability of a positive viral culture was strongly correlated to Ct values, however some samples did not follow the general trend. We found a significant correlation between plaque forming units and levels of mucosal antibodies and found that high levels of mucosal antibodies correlated with reduced chance of isolating the virus. Our data reveals essential parameters to consider from specimen collection over storage to culturing technique for optimal chance of isolating SARS-CoV-2 and accurately estimating patient contagiousness.

Effects of Different SARS-CoV-2 Testing Strategies in the Emergency Department on Length of Stay and Clinical Outcomes: A Randomised Controlled Trial

The turn-around-time (TAT) of diagnostic and screening measures such as testing for SARS-CoV-2 can affect a patient's length of stay (LOS) in the hospital as well as the emergency department (ED). This, in turn, can affect clinical outcomes. Therefore, a reliable and time-efficient SARS-CoV-2 testing strategy is necessary, especially in the ED. In this randomised controlled trial, n = 598 ED patients presenting to one of three university hospital EDs in Berlin, Germany, and needing hospitalisation were randomly assigned to two intervention groups and one control group. Accordingly, different SARS-CoV-2 testing strategies were implemented: rapid antigen and point-of-care (POC) reverse transcription polymerase chain reaction (rtPCR) testing with the Roche cobas® Liat® (LIAT) (group one n = 198), POC rtPCR testing with the LIAT (group two n = 197), and central laboratory rtPCR testing (group three, control group n = 203). The median LOS in the hospital as an inpatient across the groups was 7 days. Patients' LOS in the ED of more than seven hours did not differ significantly, and furthermore, no significant differences were observed regarding clinical outcomes such as intensive care unit stay or death. The rapid and POC test strategies had a significantly (p < 0.01) shorter median TAT (group one 00:48 h, group two 00:21 h) than the regular central laboratory rtPCR test (group three 06:26 h). However, fast SARS-CoV-2 testing strategies did not reduce ED or inpatient LOS significantly in less urgent ED admissions. Testing strategies should be adjusted to the current circumstances including crowding, SARS-CoV-2 incidences, and patient cohort. This trial is registered with DRKS00023117.