Innate immune pathway modulator screen identifies STING pathway activation as a strategy to inhibit multiple families of arbo and respiratory viruses.

RNA viruses continue to remain a threat for potential pandemics due to their rapid evolution. Potentiating host antiviral pathways to prevent or limit viral infections is a promising strategy. Thus, by testing a library of innate immune agonists targeting pathogen recognition receptors, we observe that Toll-like receptor 3 (TLR3), stimulator of interferon genes (STING), TLR8, and Dectin-1 ligands inhibit arboviruses, Chikungunya virus (CHIKV), West Nile virus, and Zika virus to varying degrees. STING agonists (cAIMP, diABZI, and 2',3'-cGAMP) and Dectin-1 agonist scleroglucan demonstrate the most potent, broad-spectrum antiviral function. Furthermore, STING agonists inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and enterovirus-D68 (EV-D68) infection in cardiomyocytes. Transcriptome analysis reveals that cAIMP treatment rescue cells from CHIKV-induced dysregulation of cell repair, immune, and metabolic pathways. In addition, cAIMP provides protection against CHIKV in a chronic CHIKV-arthritis mouse model. Our study describes innate immune signaling circuits crucial for RNA virus replication and identifies broad-spectrum antivirals effective against multiple families of pandemic potential RNA viruses.

Cardiopulmonary Outcomes in Covid-19 Patients Discharged From a Tertiary Care Center: A Prospective Study.

To determine the cardiopulmonary changes in the survivors of acute COVID-19 infection at 3-6 month and 6-12 month. We followed up 53 patients out of which 28 (52%) had mild COVID-19 and 25 (48%) had severe COVID-19. The first follow-up was between 3 month after diagnosis up to 6 month and second follow-up between 6 and 12 month from the date of diagnosis of acute COVID-19. They were monitored using vital parameters, pulmonary function tests, echocardiography and a chest computed tomography (CT) scan. We found improvement in diffusing capacity for carbon monoxide (DLCO) with a median of 52% of predicted and 80% of predicted at the first and second follow-up, respectively. There was improvement in the CTSS in severe group from 22 (18-24) to 12 (10-18; p-0.001). Multivariable logistic regression revealed increased odds of past severe disease with higher CTSS at follow-up (OR-1.7 [CI 1.14-2.77]; P = 0.01). Correlation was found between CTSS and DLCO at second follow-up (r2 = 0.36; p < 0.01). Most of patients recovered from COVID-19 but a subgroup of patients continued to have persistent radiological and pulmonary function abnormalities necessitating a structured follow-up.

Efficacy of Bacillus Calmette-Guérin (BCG) Vaccination in Reducing the Incidence and Severity of COVID-19 in High-Risk Population (BRIC): a Phase III, Multi-centre, Quadruple-Blind Randomised Control Trial.

INTRODUCTION: Universal coverage of vaccines alone cannot be relied upon to protect at-risk populations in lower- and middle-income countries against the impact of the coronavirus disease 2019 (COVID-19) pandemic and newer variants. Live vaccines, including Bacillus Calmette-Guérin (BCG), are being studied for their effectiveness in reducing the incidence and severity of COVID-19 infection. METHODS: In this multi-centre quadruple-blind, parallel assignment randomised control trial, 495 high-risk group adults (aged 18-60 years) were randomised into BCG and placebo arms and followed up for 9 months from the date of vaccination. The primary outcome was the difference in the incidence of COVID-19 infection at the end of 9 months. Secondary outcomes included the difference in the incidence of severe COVID-19 infections, hospitalisation rates, intensive care unit stay, oxygen requirement and mortality at the end of 9 months. The primary analysis was done on an intention-to-treat basis, while safety analysis was done per protocol. RESULTS: There was no significant difference in the incidence rates of cartridge-based nucleic acid amplification test (CB-NAAT) positive COVID-19 infection [odds ratio (OR) 1.08, 95% confidence interval (CI) 0.54-2.14] in the two groups, but the BCG arm showed a statistically significant decrease in clinically diagnosed (symptomatic) probable COVID-19 infections (OR 0.38, 95% CI 0.20-0.72). Compared with the BCG arm, significantly more patients developed severe COVID-19 pneumonia (CB-NAAT positive) and required hospitalisation and oxygen in the placebo arm (six versus none; p = 0.03). One patient belonging to the placebo arm required intensive care unit (ICU) stay and died. BCG had a protective efficacy of 62% (95% CI 28-80%) for likely symptomatic COVID-19 infection. CONCLUSIONS: BCG is protective in reducing the incidence of acute respiratory illness (probable symptomatic COVID-19 infection) and severity of the disease, including hospitalisation, in patients belonging to the high-risk group of COVID-19 infection, and the antibody response persists for quite a long time. A multi-centre study with a larger sample size will help to confirm the findings in this study. CLINICAL TRIALS REGISTRY: Clinical Trials Registry India (CTRI/2020/07/026668).

The Bacillus Calmette­Guérin (BCG) vaccine has been studied previously in several settings, including reducing childhood mortalities due to viral infections and induction of trained immunity and reducing upper respiratory tract infections and pneumonia in older adults. This multi-centre trial has tried to evaluate the efficacy of BCG revaccination in reducing the incidence and severity of COVID-19 infections in adults between 18 and 60 years of age belonging to the high-risk group owing to the presence of comorbidities including diabetes, chronic kidney disease, chronic liver disease and chronic lung diseases. A single dose of BCG vaccine produced significantly high titres of BCG antibodies lasting for six months. While there was no significant reduction in the incidence of COVID-19 infection, there was an 8.4% reduction in the incidence of symptomatic COVID-19 disease at the end of 9 months of follow-up. In addition, there were significantly fewer severe COVID-19 infections requiring hospital stay and oxygen support. However, the overall numbers of severe COVID-19 infections were low. Thus, the study shows that BCG can protect against symptomatic and severe COVID-19 disease. However, it might not reduce the incidence of new infections. The study results are significant for low- and middle-income countries without adequate coverage of primary doses of COVID-19 vaccination, let alone the booster doses. Future studies should evaluate the BCG vaccine's efficacy as a booster compared with routine COVID-19 vaccine boosters.

In Silico Genome Analysis Reveals the Evolution and Potential Impact of SARS-CoV-2 Omicron Structural Changes on Host Immune Evasion and Antiviral Therapeutics.

New variants of SARS-CoV-2 continue to evolve. The novel SARS-CoV-2 variant of concern (VOC) B.1.1.529 (Omicron) was particularly menacing due to the presence of numerous consequential mutations. In this study, we reviewed about 12 million SARS-CoV-2 genomic and associated metadata using extensive bioinformatic approaches to understand how evolutionary and mutational changes affect Omicron variant properties. Subsampled global data based analysis of molecular clock in the phylogenetic tree showed 29.56 substitutions per year as the evolutionary rate of five VOCs. We observed extensive mutational changes in the spike structural protein of the Omicron variant. A total of 20% of 7230 amino acid and structural changes exclusive to Omicron's spike protein were detected in the receptor binding domain (RBD), suggesting differential selection pressures exerted during evolution. Analyzing key drug targets revealed mutation-derived differential binding affinities between Delta and Omicron variants. Nine single-RBD substitutions were detected within the binding site of approved therapeutic monoclonal antibodies. T-cell epitope prediction revealed eight immunologically important functional hotspots in three conserved non-structural proteins. A universal vaccine based on these regions may likely protect against all these SARS-CoV-2 variants. We observed key structural changes in the spike protein, which decreased binding affinities, indicating that these changes may help the virus escape host cellular immunity. These findings emphasize the need for continuous genomic surveillance of SARS-CoV-2 to better understand how novel mutations may impact viral spread and disease outcome.

Prevalence of Long COVID-19 and its Impact on Quality of Life Among Outpatients With Mild COVID-19 Disease at Tertiary Care Center in North India.

Literature is lacking on the spectrum of symptoms of long COVID-19 (defined as symptoms persisting beyond 28 days of diagnosis) and its impact on quality of life. This single-center, cross-sectional study included mild COVID-19 cases as determined by a positive real-time reverse transcription polymerase chain reaction test. Patients were contacted at least 28 days after diagnosis and were interviewed telephonically using semi-structured questionnaires for duration of symptoms, fatigue using Fatigue Severity Scale (FSS) and quality of life using the World Health Organization Quality of Life: Brief Version (WHOQOL-BREF). A total of 251 COVID-19 patients were included; of which 169 (67.3%) were males. The mean age of the patients was 35.8 years (SD = 12.5). The prevalence of long COVID-19 was 28.2% (n = 71, 95% CI: 23.0-34.2). The most common symptoms involved the musculoskeletal system (12.7%), upper respiratory tract (7.6%), and fatigue among 17 (6.8%) patients. Patients with long COVID-19 had significantly higher FSS score and lower WHOQOL-BREF score compared to the patients without long COVID-19 (<28 days).

Th1/Th2/Th17 Cytokine Profile among Different Stages of COVID-19 Infection.

Aim: To characterize Th1/Th2/Th17 cytokine profile (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ, and IL-17A) among different stages of COVID-19 infection. Methods: This was a cross-sectional study which included six healthy individuals and 68 patients who were admitted with COVID-19 in the Department of Medicine, at All India Institute of Medical Sciences, New Delhi, from July 2020 to September 2020. Patients were categorized into mild, moderate, and severe COVID-19 groups, and serum samples were drawn for the measurement of Th1/Th2/Th17 cytokines (IL-4, IL-6, IL-10, TNF-α, IFN-γ, and IL-17A) which was done by BD™ Cytometric Bead Array. Results: All the cytokines showed dynamic expression in the COVID-19 group, of which only IL-6 was statistically significant. Among the three severity groups of COVID-19, increased severity did not transform into increased cytokine level, with the exception for IL-6, which was statistically significant. Conclusions: In our small sample study, six cytokines expressions were evaluated however most of them were elevated in COVID-19 patients but were not statistically significant except IL-6.

Evaluation of Host Protein Biomarkers by ELISA From Whole Lysed Peripheral Blood for Development of Diagnostic Tests for Active Tuberculosis.

Tuberculosis (TB) remains a significant global health crisis and the number one cause of death for an infectious disease. The health consequences in high-burden countries are significant. Barriers to TB control and eradication are in part caused by difficulties in diagnosis. Improvements in diagnosis are required for organisations like the World Health Organisation (WHO) to meet their ambitious target of reducing the incidence of TB by 50% by the year 2025, which has become hard to reach due to the COVID-19 pandemic. Development of new tests for TB are key priorities of the WHO, as defined in their 2014 report for target product profiles (TPPs). Rapid triage and biomarker-based confirmatory tests would greatly enhance the diagnostic capability for identifying and diagnosing TB-infected individuals. Protein-based test methods e.g. lateral flow devices (LFDs) have a significant advantage over other technologies with regard to assay turnaround time (minutes as opposed to hours) field-ability, ease of use by relatively untrained staff and without the need for supporting laboratory infrastructure. Here we evaluate the diagnostic performance of nine biomarkers from our previously published biomarker qPCR validation study; CALCOCO2, CD274, CD52, GBP1, IFIT3, IFITM3, SAMD9L, SNX10 and TMEM49, as protein targets assayed by ELISA. This preliminary evaluation study was conducted to quantify the level of biomarker protein expression across latent, extra-pulmonary or pulmonary TB groups and negative controls, collected across the UK and India, in whole lysed blood samples (WLB). We also investigated associative correlations between the biomarkers and assessed their suitability for ongoing diagnostic test development, using receiver operating characteristic/area under the curve (ROC) analyses, singly and in panel combinations. The top performing single biomarkers for pulmonary TB versus controls were CALCOCO2, SAMD9L, GBP1, IFITM3, IFIT3 and SNX10. TMEM49 was also significantly differentially expressed but downregulated in TB groups. CD52 expression was not highly differentially expressed across most of the groups but may provide additional patient stratification information and some limited use for incipient latent TB infection. These show therefore great potential for diagnostic test development either in minimal configuration panels for rapid triage or more complex formulations to capture the diversity of disease presentations.

Effectiveness of an inactivated virus-based SARS-CoV-2 vaccine, BBV152, in India: a test-negative, case-control study.

BACKGROUND: BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine that has been deployed in India. The results of the phase 3 trial have shown clinical efficacy of BBV152. We aimed to evaluate the effectiveness of BBV152 against symptomatic RT-PCR-confirmed SARS-CoV-2 infection. METHODS: We conducted a test-negative, case-control study among employees of the All India Institute of Medical Sciences (a tertiary care hospital in New Delhi, India), who had symptoms suggestive of COVID-19 and had an RT-PCR test for SARS-CoV-2 during the peak of the second wave of the COVID-19 pandemic in India between April 15 and May 15, 2021. Cases (test-positives) and controls (test-negatives) were matched (1:1) on the basis of age and gender. The odds of vaccination with BBV152 were compared between cases and controls and adjusted for level of occupational exposure (to COVID-19), previous SARS-CoV-2 infection, and calendar time, using conditional logistic regression. The primary outcome was effectiveness of two doses of BBV152 (with the second dose received at least 14 days before testing) in reducing the odds of symptomatic RT-PCR-confirmed SARS-CoV-2 infection, expressed as (1 - odds ratio) × 100%. FINDINGS: Between April 15 and May 15, 2021, 3732 individuals had an RT-PCR test. Of these, 2714 symptomatic employees had data on vaccination status, and 1068 matched case-control pairs were available for analysis. The adjusted effectiveness of BBV152 against symptomatic COVID-19 after two doses administered at least 14 days before testing was 50% (95% CI 33-62; p<0·0001). The adjusted effectiveness of two doses administered at least 28 days before testing was 46% (95% CI 22-62) and administered at least 42 days before testing was 57% (21-76). After excluding participants with previous SARS-CoV-2 infections, the adjusted effectiveness of two doses administered at least 14 days before testing was 47% (95% CI 29-61). INTERPRETATION: This study shows the effectiveness of two doses of BBV152 against symptomatic COVID-19 in the context of a huge surge in cases, presumably dominated by the potentially immune-evasive delta (B.1.617.2) variant of SARS-CoV-2. Our findings support the ongoing roll-out of this vaccine to help control the spread of SARS-CoV-2, while continuing the emphasis on adherence to non-pharmacological measures. FUNDING: None. TRANSLATION: For the Hindi translation of the abstract see Supplementary Materials section.

Risk factors for Coronavirus disease-associated mucormycosis.

BACKGROUND: The epidemiology of the Coronavirus-disease associated mucormycosis (CAM) syndemic is poorly elucidated. We aimed to identify risk factors that may explain the burden of cases and help develop preventive strategies. METHODS: We performed a case-control study comparing cases diagnosed with CAM and taking controls as recovered COVID 19 patients who did not develop mucormycosis. Information on comorbidities, glycemic control, and practices related to COVID-19 prevention and treatment was recorded. Multivariate regression analysis was used to identify independent predictors. RESULTS: A total of 352 patients (152 cases and 200 controls) diagnosed with COVID-19 during April-May 2021 were included. In the CAM group, symptoms of mucormycosis began a mean of 18.9 (SD 9.1) days after onset of COVID-19, and predominantly rhino-sinus and orbital involvement was present. All, but one, CAM cases had conventional risk factors of diabetes and steroid use. On multivariable regression, increased odds of CAM were associated with the presence of diabetes (adjusted OR 3.5, 95% CI 1.1-11), use of systemic steroids (aOR 7.7, 95% CI 2.4-24.7), prolonged use of cloth and surgical masks (vs. no mask, aOR 6.9, 95%CI 1.5-33.1), and repeated nasopharyngeal swab testing during the COVID-19 illness (aOR 1.6, 95% CI 1.2-2.2). Zinc therapy was found to be protective (aOR 0.05, 95%CI 0.01-0.19). Notably, the requirement of oxygen supplementation or hospitalization did not affect the risk of CAM. CONCLUSION: Judicious use of steroids and stringent glycemic control are vital to preventing mucormycosis. Use of clean masks, preference for N95 masks if available, and minimizing swab testing after the diagnosis of COVID-19 may further reduce the incidence of CAM.

COVID-19-associated subacute invasive pulmonary aspergillosis.

BACKGROUND: Though invasive pulmonary aspergillosis is a well known complication of COVID-19 pneumonia, indolent forms of aspergillosis have been rarely described. METHODS: We prospectively collected the clinico-radio-microbiological data of 10 patients of subacute invasive pulmonary aspergillosis (SAIA), who presented to our hospital with recent history of COVID-19 pneumonia along with cavitary lung disease, positive IgG (against Aspergillus) with or without positive respiratory samples for Aspergillus spp. RESULT: The mean age of presentation of SAIA was 50.7 ± 11.8 years. All the patients had recently recovered from severe COVID-19 illness with a mean duration of 29.2 ± 12 days from COVID-19 positivity. Cough was the predominant symptom seen in 8/10 (80%) patients followed by haemoptysis. 7/10 (70%) patients were known diabetic. While serum galactomannan was positive in 5/9 patients (55.5%), fungal culture was positive in 2/7 patients (28.5%) and polymerase chain reaction (PCR) for Aspergillus was positive in three patients. Eight (80%) patients presented with a single cavitary lesion; pseudoaneurysm of pulmonary artery was seen in two patients and post-COVID-19 changes were seen in all patients. All patients were treated with voriconazole, out of which four (40%) patients died during the follow-up period. CONCLUSION: SAIA should be considered in the differential diagnosis of cavitating lung lesions in patients with recent history of COVID-19 in the background of steroid use with or without pre-existing diabetes.

Post COVID-19 sequelae: A prospective observational study from Northern India.

Post COVID-19 sequelae are a constellation of symptoms often reported after recovering from COVID-19. There is a need to better understand the clinical spectrum and long-term course of this clinical entity. The aim of this study is to describe the clinical features and risk factors of post COVID-19 sequelae in the North Indian population. This prospective observational study was conducted at a tertiary healthcare centre in Northern India between October 2020 and February 2021. Patients aged >18 years with laboratory-confirmed COVID-19 were recruited after at least two weeks of diagnosis, and details were captured. A total of 1234 patients were recruited and followed up for a median duration of 91 days (IQR: 45-181 days). Among them, 495 (40.1%) had persistent symptoms post-discharge or recovery. In 223 (18.1%) patients, the symptoms resolved within four weeks; 150 (12.1%) patients had symptoms till 12 weeks, and 122 (9.9%) patients had symptoms beyond 12 weeks of diagnosis/symptom-onset of COVID-19. Most common symptoms included myalgia (10.9%), fatigue (5.5%), shortness of breath (6.1%), cough (2.1%), insomnia (1.4%), mood disturbances (0.48%) and anxiety (0.6%). Patients who were hospitalized were more likely to report fatigue as a feature of long COVID. Hypothyroidism (OR: 4.13, 95% CI: 2.2-7.6, p-value < 0.001) and hypoxia (SpO2 ≤ 93%) (OR: 1.7, 95% CI: 1.1-2.4, p-value 0.012) were identified as risk factors for long COVID sequelae. In conclusion, long COVID symptoms were common (22%), and 9.9% had the post COVID-19 syndrome. Myalgias, fatigue and dyspnoea were common symptoms. Patients with hypothyroidism and hypoxia during acute illness were at higher risk of long COVID.

Impact of metabolic and cardiovascular disease on COVID-19 mortality: A systematic review and meta-analysis.

BACKGROUND AND AIMS: This meta-analysis aims to highlight the impact of cardio-metabolic comorbidities on COVID-19 severity and mortality. METHODS: A thorough search on major online databases was done for studies describing the clinical outcomes of COVID-19 patients. We used random-effects model to compute pooled estimates for critical or fatal disease. RESULTS: A total of 20,475 patients from 33 eligible studies were included. Maximum risk of development of critical or fatal COVID-19 disease was seen in patients with underlying cardiovascular disease [OR: 3.44, 95% CI: 2.65-4.48] followed by chronic lung disease, hypertension and diabetes mellitus. Of the total cases, 64% had one of the four comorbidities with the most prevalent being hypertension with a pooled prevalence of 27%. CONCLUSIONS: Presence of comorbidities like cardiovascular disease, chronic lung disease, hypertension and diabetes mellitus led to a higher risk of development of critical or fatal COVID-19 disease, with maximum risk seen with underlying cardiovascular disease.

Impact of COVID-19 on the patients' income and work in Delhi, India.

BACKGROUND: Currently, there is no data on the impact of COVID-19 on patients' income and work in India. METHODS: We conducted a cross-sectional study at a tertiary hospital in New Delhi. We included all the patients who were ≥18 years of age and consecutively diagnosed with COVID-19 between the 1st of May 2020 to 31st July 2020. Patients were interviewed by a physician using a semi-structure questionnaire. Data were collected on socio-economic status, occupation, income loss, leaves taken, decrease in work efficiency (self-perceived) and about-facing any stigma/discrimination at the workplace. RESULTS: Out of 245 patients, 190 patients were employed. A total of 126 patients (66.3%) self-reported their work was affected due to COVID-19 disease. A total of 30.5% of patients (n = 58/190) reported deduction in their salary. The median amount of salary loss was INR 10,000 (IQR 9000-25000). Decrease in income and work efficiency (self-perceived) was found to be 37.3% (n = 71) and 12.1% (n = 23), respectively. A total of 47 patients (37.3%) took personal leaves (median number - 17 days (IQR 14-25), and discrimination/stigma related to the COVID-19 at the workplace was faced by 22.6% of patients. CONCLUSION: Income and work of a substantial number of patients was affected due to COVID-19, as there was a decrease in income and work efficiency. Patients also had to take personal leaves and face stigma in the workplace. This will inform the policymakers to formulate strategies to mitigate the impact of COVID-19.

Gargle lavage & saliva: Feasible & cheaper alternatives to nasal & throat swabs for diagnosis of COVID-19.

Background & objectives: In the present scenario, the most common sample for diagnosis of COVID-19 by reverse transcription polymerase chain reaction (RT-PCR) is nasal and throat swab (NTS). Other sampling options such as gargle lavage have found limited application in clinical use mostly because of unavailability of an appropriate gargling liquid. This study was conducted to assess the stability of SARS-CoV-2 RNA in normal saline at 4°C that can serve as a gargling liquid as well as a transport medium. The study also looked at the agreement between NTS and gargle lavage/saliva for the detection of SARS-CoV-2. Methods: In 29 consecutive real-time RT-PCR (rRT-PCR) positive COVID-19 patients, paired NTS, gargle and saliva samples were taken. Samples were processed by rRT-PCR for the detection of SARS-CoV-2 RNA. To assess the SARS-CoV-2 RNA stability in normal saline, gargle lavage specimens were divided into two aliquots; one subset of the specimen was run within 4-6 h along with the routine samples (NTS and saliva) and the other subset was stored at 4°C and processed after 24-30 h. Agreement between cycle threshold (Ct) values from both the runs was compared using Bland-Altman (BA) analysis. Results: The positivity rates of rRT-PCR in NTS, saliva and gargle lavage samples were 82.7 (24/29), 79.3 (23/29) and 86.2 per cent (25/29), respectively. BA plot showed a good agreement between the Ct values of fresh and stored gargle samples, stipulating that there were no significant differences in the approximate viral load levels between the fresh and stored gargle lavage samples (bias: E gene -0.64, N gene -0.51, ORF gene -0.19). Interpretation & conclusions: Our study results show stability of SARS-CoV-2 RNA in the gargle samples collected using normal saline up to 24-30 h. Gargle lavage and saliva specimen collection are cost-effective and acceptable methods of sampling for the detection of SARS-CoV-2 RNA by rRT-PCR. These simplified, inexpensive and acceptable methods of specimen collection would reduce the cost and workload on healthcare workers for sample collection.

Management of COVID-19 from the pulmonologist's perspective: a narrative review.

Introduction: The COVID-19 pandemic has provided global challenges to health-care facilities in ensuring the delivery of care to patients. Tremendous international collaboration has enabled the swift formulation of evidence-based guidelines that aim to clarify day-to-day issues faced by physicians and other health-care providers on the frontlines.Areas covered: In order to provide answers to the common questions and dilemmas faced by physicians and policymakers, especially those handling pulmonary manifestations of COVID-19, the authors made a list of pertinent clinical topics that were reviewed between 21st of August, 2020 to 30th of August, 2020 by the authors using online databases that included PubMed, EBSCO, and the Cochrane Library. Literature was reviewed and included based on relevance to the topics selected. The review was aimed to serve as a quick reference for addressing practical issues faced during patient care in the ongoing pandemic with a brief account of the management of COVID-19 patients as per international guidelines.Expert opinion: As more evidence continues to generate regarding the optimal methods of managing COVID-19 cases while caring for non-COVID patients concurrently, physicians will need to constantly reeducate themselves to keep pace with a rapidly evolving landscape of therapeutic options.

Gargle lavage as a viable alternative to swab for detection of SARS-CoV-2.

BACKGROUND & OBJECTIVES: Nasopharyngeal and oropharyngeal swab (NPS and OPS) collection is widely accepted as the preferred method for obtaining respiratory samples. However, it has certain disadvantages which may be overcome by gargling. The primary objective of this study was to assess agreement between gargle lavage and swab as an appropriate respiratory sample for the detection of SARS-CoV-2. The secondary objective was to assess the patient acceptability of the two sampling methods. METHODS: It was a cross-sectional study done at a tertiary care hospital in New Delhi, India, on 50 confirmed COVID-19 patients. Paired swab (NPS and OPS) and gargle samples were taken within 72 h of their diagnosis. Samples were processed by reverse transcription-polymerase chain reaction (RT-PCR) for detection of SARS-CoV-2. Post-sample collection, a 10-point scale was administered to assess the level of discomfort with either of the collection methods. RESULTS: All gargle samples were positive and comparable to their corresponding swab samples irrespective of the symptoms and duration of illness. The cycle threshold (Ct) values for gargle samples were slightly higher but comparable to those of swabs. Bland-Altman plot showed good agreement between the two methods. Majority (72%) of the patients reported moderate-to-severe discomfort with swab collection in comparison to 24 per cent reporting only mild discomfort with gargle collection. INTERPRETATION & CONCLUSIONS: Our preliminary results show that the gargle lavage may be a viable alternative to swabs for sample collection for the detection of SARS-CoV-2. Adoption of gargle lavage for sample collection will have a significant impact as it will enable easy self-collection, relieve healthcare workers and also lead to substantial cost savings by reducing the need for swabs and personal protective equipment.