Cytomegalovirus reactivation in a SARS-CoV-2 infected woman experiencing fetal demise in the first trimester with fetal trisomy 21: A case report.

Cytomegalovirus (CMV) is the most common cause of congenital viral infections. Women seropositive for CMV prior to pregnancy can develop a non-primary CMV infection. Here, we present a case of first trimester pregnancy loss during active SARS-CoV-2 infection. There was no evidence of SARS-CoV-2 RNA in placenta and fetal tissue, but there was presence of congenital cytomegalovirus infection by nested PCR. To the best of our knowledge, this is the first report demonstrating association of early congenital CMV infection due to reactivation and fetal demise in a SARS-CoV-2 positive woman with fetal trisomy 21.

Opposing roles for sMAdCAM and IL-15 in COVID-19 associated cellular immune pathology.

Immune cell dysregulation and lymphopenia characterize COVID-19 pathology in moderate to severe disease. While underlying inflammatory factors have been extensively studied, homeostatic and mucosal migratory signatures remain largely unexplored as causative factors. In this study, we evaluated the association of circulating IL-6, soluble mucosal addressin cell adhesion molecule (sMAdCAM), and IL-15 with cellular dysfunction characterizing mild and hypoxemic stages of COVID-19. A cohort of SARS-CoV-2 infected individuals (n = 130) at various stages of disease progression together with healthy controls (n = 16) were recruited from COVID Care Centres (CCCs) across Mumbai, India. Multiparametric flow cytometry was used to perform in-depth immune subset characterization and to measure plasma IL-6 levels. sMAdCAM, IL-15 levels were quantified using ELISA. Distinct depletion profiles, with relative sparing of CD8 effector memory and CD4+ regulatory T cells, were observed in hypoxemic disease within the lymphocyte compartment. An apparent increase in the frequency of intermediate monocytes characterized both mild as well as hypoxemic disease. IL-6 levels inversely correlated with those of sMAdCAM and both markers showed converse associations with observed lympho-depletion suggesting opposing roles in pathogenesis. Interestingly, IL-15, a key cytokine involved in lymphocyte activation and homeostasis, was detected in symptomatic individuals but not in healthy controls or asymptomatic cases. Further, plasma IL-15 levels negatively correlated with T, B, and NK count suggesting a compensatory production of this cytokine in response to the profound lymphopenia. Finally, higher levels of plasma IL-15 and IL-6, but not sMAdCAM, were associated with a longer duration of hospitalization.

Cycle threshold values in RT-PCR to determine dynamics of SARS-CoV-2 viral load: An approach to reduce the isolation period for COVID-19 patients.

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected all inhabited continents, and India is currently experiencing a devastating second wave of coronavirus disease-2019 (COVID-19). Here, we examined the duration of clearance of SARS-CoV-2 in respiratory samples from 207 infected cases by real-time reverse-transcription polymerase chain reaction (RT-PCR). A substantial proportion of COVID-19 positive cases with cycle threshold (Ct) values more than or equal to 31 (45.7%) were subsequently tested negative for SARS-CoV-2 RNA within 7 days of initial detection of the viral load. A total of 60% of all the patients with COVID-19, irrespective of their Ct values, cleared SARS-CoV-2 RNA within 14 days of the initial detection. Longitudinal assessment of RT-PCR test results in individuals requiring 15-30 days to clear SARS-CoV-2 RNA showed a significant reduction of the viral load in samples with high or intermediate viral loads (Ct values ≤ 25 and between 26 and 30, respectively) but the follow-up group with low viral RNA (Ct values ≥ 31) exhibited a stable viral load. Together, these results suggest that COVID-19 positive cases with Ct values more than or equal to 31 require reduced duration to clear SARS-CoV-2, and thus, a shorter isolation period for this group might be considered to facilitate adequate space in the COVID Care Centres and reduce the burden on healthcare infrastructure.

sMAdCAM: IL-6 Ratio Influences Disease Progression and Anti-Viral Responses in SARS-CoV-2 Infection.

The role of sMAdCAM, an important gut immune migratory marker, remains unexplored in COVID-19 pathogenesis considering recent studies positing the gut as a sanctuary site for SARS-CoV-2 persistence. Thus, assimilating profiles of systemic inflammatory mediators with sMAdCAM levels may provide insights into the progression of COVID-19 disease. Also, the role of these markers in governing virus specific immunity following infection remains largely unexplored. A cohort (n = 84) of SARS-C0V-2 infected individuals included a group of in-patients (n = 60) at various stages of disease progression together with convalescent individuals (n = 24) recruited between April and June 2020 from Mumbai, India. Follow-up of 35 in-patients at day 7 post diagnosis was carried out. Th1/Th2/Th17 cytokines along with soluble MAdCAM (sMAdCAM) levels in plasma were measured. Also, anti-viral humoral response as measured by rapid antibody test (IgG, IgM), Chemiluminescent Immunoassay (IgG), and antibodies binding to SARS-CoV-2 proteins were measured by Surface Plasmon Resonance (SPR) from plasma. IL-6 and sMAdCAM levels among in-patients inversely correlated with one another. When expressed as a novel integrated marker-sMIL index (sMAdCAM/IL-6 ratio)-these levels were incrementally and significantly higher in various disease states with convalescents exhibiting the highest values. Importantly, sMAdCAM levels as well as sMIL index (fold change) correlated with peak association response units of receptor binding domain and fold change in binding to spike respectively as measured by SPR. Our results highlight key systemic and gut homing parameters that need to be monitored and investigated further to optimally guide therapeutic and prophylactic interventions for COVID-19.

A novel ORF1a-based SARS-CoV-2 RT-PCR assay to resolve inconclusive samples.

BACKGROUND: India bears the second largest burden of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. A multitude of reverse transcription polymerase chain reaction (RT-PCR) detection assays with disparate gene targets, including automated high-throughput platforms, are available. Varying concordance and interpretation of diagnostic results in this setting can result in significant reporting delays, leading to suboptimal disease management. This article reports the development of a novel ORF1a-based SARS-CoV-2 RT-PCR assay - Viroselect - that shows high concordance with conventional assays and the ability to resolve inconclusive results generated during the peak of the epidemic in Mumbai, India. METHODS: A unique target region within SARS-CoV-2 ORF1a - the non-structural protein 3 (nsp3) region - was used to design and develop the assay. This hypervariable region (1923-3956) between SARS-CoV-2, SARS-CoV-1 and Middle East respiratory syndrome coronavirus was utilized to design the primers and probes for the RT-PCR assay. The concordance of this assay with commonly used emergency use authorization (US Food and Drug Administration) manual kits and an automated high-throughput testing platform was evaluated. Further, a retrospective analysis was carried out using Viroselect on samples reported as 'inconclusive' between April and October 2020. RESULTS: In total, 701 samples were tested. Concordance analysis of 477 samples demonstrated high overall agreement of Viroselect with both manual (87.6%) and automated (84.7%) assays. Also, in the retrospective analysis of 224 additional samples reported as 'inconclusive', Viroselect was able to resolve 100% (19/19) and 93.7% (192/205) of samples which had inconclusive results on manual and automated high-throughput platforms, respectively. CONCLUSION: Viroselect had high concordance with conventional assays, both manual and automated, and has potential to resolve inconclusive samples.

A retrospective analysis of COVID-19 diagnosis results obtained by rapid antigen tests and RT-PCR: Implications for disease management.

There is a need for understanding and establishment of the most appropriate testing algorithm for COVID-19 diagnosis in asymptomatic high-risk groups. Here, we present a retrospective analysis of RT-PCR results obtained from 412 cases tested negative for coronavirus disease 2019 (COVID-19) by rapid antigen testing method. Among 178 (43.2%) asymptomatic individuals, 44.9% of the high risk contacts, 12.2% of police custody individuals, 22.22% of the pregnant women and 33.33% of individuals hospitalised for preoperative or other medical conditions showed RT-PCR positivity. Our results suggest a need for focussed and intensive (multi-modality) testing in groups at high risk for SARS-CoV-2 infection.

Detection of SARS-CoV-2 infection by RT-PCR test: factors influencing interpretation of results.

In this current pandemic of coronavirus disease 2019 (COVID-19), prompt interventions in terms of early detection and clinical management along with isolation of positive cases is of utmost importance. This helps to limit not only the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections but also the morbidity and mortality associated with it. Different strategies for screening of COVID-19 in containment zones and non-containment areas include testing of symptomatic patients and their contacts in fever clinics, hospital-based testing, testing on demand and population-based screening. The choice of tests like reverse-transcription polymerase chain reaction (RT-PCR), rapid antigen testing (RAT) or antibody test depends upon these strategies and also the turnaround time. Currently, RT-PCR is considered the gold standard for COVID-19 detection. This commentary provides the insights and experiences on COVID-19 diagnosis by RT-PCR. The utility of this test is limited by several false positive, false negative and inconclusive results at early stages of infection, scarcity of reagents and lack of well-equipped labs including trained staff. Moreover, appropriate sample collection and transport, standard laboratory protocols, stringent quality control norms, good quality RNA extraction kits, PCR kits with suitable primers can help in improving accuracy of the test results. A careful assessment of clinical, radiological and molecular findings is required for identifying potential cases of COVID-19.

Persistence of SARS-CoV-2 in the first trimester placenta leading to transplacental transmission and fetal demise from an asymptomatic mother.

Coronavirus disease 2019 (COVID-19) is caused by infection of the respiratory tract by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which survives in the tissues during the clinical course of infection but there is limited evidence on placental infection and vertical transmission of SARS-CoV-2. The impact of COVID-19 in first trimester pregnancy remains poorly understood. Moreover, how long SARS-CoV-2 can survive in placenta is unknown. Herein, we report a case of a pregnant woman in the first trimester who tested positive for SARS-CoV-2 at 8 weeks of gestation, although her clinical course was asymptomatic. At 13 weeks of gestation, her throat swab tested negative for SARS-CoV-2 but viral RNA was detected in the placenta, and the Spike (S) proteins (S1 and S2) were immunolocalized in cytotrophoblast and syncytiotrophoblast cells of the placental villi. Histologically, the villi were generally avascular with peri-villus fibrin deposition and in some areas the syncytiotrophoblast layer appeared lysed. The decidua also had fibrin deposition with extensive leukocyte infiltration suggestive of inflammation. The SARS-CoV-2 crossed the placental barrier, as the viral RNA was detected in the amniotic fluid and the S proteins were detected in the fetal membrane. Ultrasonography revealed extensively subcutaneous edema with pleural effusion suggestive of hydrops fetalis and the absence of cardiac activity indicated fetal demise. This is the first study to provide concrete evidence of persistent placental infection of SARS-CoV-2 and its congenital transmission is associated with hydrops fetalis and intrauterine fetal demise in early pregnancy.