Analysis of SARS-CoV-2 in Corneal Tissue of Deceased Asymptomatic Novel Coronavirus Disease 2019 Donors.

PURPOSE: The aim of this study was to analyze the presence of the SARS-CoV-2 virus in the corneal tissue of asymptomatic deceased novel coronavirus disease 2019 (COVID-19) patients. METHODS: This was a cross-sectional study performed at a tertiary eye hospital. All corneas of the deceased asymptomatic donors who tested positive for SARS-CoV-2 on a nasopharyngeal swab at the time of corneal tissue harvesting were included in the study. Histopathological examination and immunohistochemistry were performed. mRNA in situ hybridization for SARS-CoV-2 was performed in all specimens that showed positive immunostaining. The main outcome measure was the presence of SARS-CoV-2 virus in the corneal tissues. RESULTS: Twenty-two corneal tissues of 11 donors were analyzed. The mean age was 72.2 ± 14.2 years. On histological examination, no signs of inflammation or any other abnormalities were detected in the cornea and adjacent bulbar conjunctiva. Immunohistochemistry revealed faint to moderate cytoplasmic staining in the basal layer of the corneal epithelium in 8 specimens from 5 patients. None of the specimens with positive immunostaining showed the presence of SARS-CoV-2 mRNA. CONCLUSIONS: In line with previous studies , our study also reflects the absence of SARS-CoV-2 viral mRNA in corneal tissues of clinically asymptomatic deceased COVID-19 donors, thereby indicating a probable low risk of transmission of the SARS-CoV-2 virus through the transplantation of corneas from donors who tested positive for, but were asymptomatic for COVID-19. In addition, further studies on the subject should include histopathological examination because of the false positive and negative rates of molecular tests.

Rate of shed of SARS COV-2 viral RNA from COVID-19 cadavers.

BACKGROUND: At what rate does the RNA of SARS CoV-2 shed from cadavers? Although, there have been numerous studies which have demonstrated the persistence of the virus on dead bodies, there is a lack of conclusive evidence regarding the variation of viral RNA content in cadavers. This has led to a knowledge gap regarding the safe handling/management of COVID-19 decedents, posing a barrier in forensic investigations. METHODS: In this study, we report the presence of RNA of SARS CoV-2 by real time RT-PCR, in nasopharyngeal swabs collected after death from two groups of bodies - one who died due to COVID-19 and the other who died due to other diagnoses. A prospective study on 199 corpses, who had tested positive for COVID-19 ante-mortem, was conducted at a tertiary care center. RNA testing was conducted at different time intervals (T1-T5). RESULTS: 112(56.3%) died primarily due to COVID-19 and 87(43.7%) died due to other diagnoses. 144(72.4%) were male and 55(27.6%) were female. A total of 115 (57.8%) tested positive for COVID-19 after death at different time points. The mean age was 50.7 ± 18.9 years and the length of hospitalization ranged from 1 to 50 days with a mean of 9.2 ± 7.6 days. Realtime RT-PCR positivity of SARS CoV-2 RNA decreases with time. CONCLUSION: We observed that real time RT-PCR positivity, indicating viral RNA detection, decreases with time. Therefore, it is advisable to follow appropriate COVID-19 precautions to carry out scientific studies, medico-legal investigations and mortuary services on suspected/confirmed COVID-19 corpses.

Effectiveness of BBV152/Covaxin and AZD1222/Covishield vaccines against severe COVID-19 and B.1.617.2/Delta variant in India, 2021: a multi-centric hospital-based case-control study.

OBJECTIVES: India introduced BBV152/Covaxin and AZD1222/Covishield vaccines in January 2021. We estimated the effectiveness of these vaccines against severe COVID-19 among individuals aged ≥45 years. METHODS: We did a multi-centric, hospital-based, case-control study between May and July 2021. Cases were severe COVID-19 patients, and controls were COVID-19 negative individuals from 11 hospitals. Vaccine effectiveness (VE) was estimated for complete (2 doses ≥ 14 days) and partial (1 dose ≥ 21 days) vaccination; interval between two vaccine doses and vaccination against the Delta variant. We used the random effects logistic regression model to calculate the adjusted odds ratios (aOR) with a 95% confidence interval (CI) after adjusting for relevant known confounders. RESULTS: We enrolled 1143 cases and 2541 control patients. The VE of complete vaccination was 85% (95% CI: 79-89%) with AZD1222/Covishield and 71% (95% CI: 57-81%) with BBV152/Covaxin. The VE was highest for 6-8 weeks between two doses of AZD1222/Covishield (94%, 95% CI: 86-97%) and BBV152/Covaxin (93%, 95% CI: 34-99%). The VE estimates were similar against the Delta strain and sub-lineages. CONCLUSION: BBV152/Covaxin and AZD1222/Covishield were effective against severe COVID-19 among the Indian population during the period of dominance of the highly transmissible Delta variant in the second wave of the pandemic. An escalation of two-dose coverage with COVID-19 vaccines is critical to reduce severe COVID-19 and further mitigate the pandemic in the country.

Identification of Human Case of Avian Influenza A(H5N1) Infection, India.

A 11-year-old boy with acute myeloid leukemia was brought for treatment of severe acute respiratory infection in the National Capital Region, New Delhi, India. Avian influenza A(H5N1) infection was laboratory confirmed. Complete genome analysis indicated hemagglutinin gene clade 2.3.2.1a. We found the strain to be susceptible to amantadine and neuraminidase inhibitors.

Zika a Vector Borne Disease Detected in Newer States of India Amidst the COVID-19 Pandemic.

Background: During the second wave of the COVID-19 pandemic, outbreaks of Zika were reported from Kerala, Uttar Pradesh, and Maharashtra, India in 2021. The Dengue and Chikungunya negative samples were retrospectively screened to determine the presence of the Zika virus from different geographical regions of India. Methods: During May to October 2021, the clinical samples of 1475 patients, across 13 states and a union territory of India were screened and re-tested for Dengue, Chikungunya and Zika by CDC Trioplex Real time RT-PCR. The Zika rRTPCR positive samples were further screened with anti-Zika IgM and Plaque Reduction Neutralization Test. Next generation sequencing was used for further molecular characterization. Results: The positivity was observed for Zika (67), Dengue (121), and Chikungunya (10) amongst screened cases. The co-infections of Dengue/Chikungunya, Dengue/Zika, and Dengue/Chikungunya/Zika were also observed. All Zika cases were symptomatic with fever (84%) and rash (78%) as major presenting symptoms. Of them, four patients had respiratory distress, one presented with seizures, and one with suspected microcephaly at birth. The Asian Lineage of Zika and all four serotypes of Dengue were found in circulation. Conclusion: Our study indicates the spread of the Zika virus to several states of India and an urgent need to strengthen its surveillance.

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.

COVID-19 disease in hospitalized young adults in India and China: Evaluation of risk factors predicting progression across two major ethnic groups.

Data pertaining to risk factor analysis in coronavirus disease 2019 (COVID-19) is confounded by the lack of data from an ethnically diverse population. In addition, there is a lack of data for young adults. This study was conducted to assess risk factors predicting COVID-19 severity and mortality in hospitalized young adults. A retrospective observational study was conducted at two centers from China and India on COVID-19 patients aged 20-50 years. Regression analysis to predict adverse outcomes was performed using parameters including age, sex, country of origin, hospitalization duration, comorbidities, lymphocyte count, and National Early Warning Score 2 (NEWS2) score at admission. A total of 420 patients (172 East Asians and 248 South Asians) were included. The predictive model for intensive care unit (ICU) admission with variables NEWS2 Category II and higher, diabetes mellitus, liver dysfunction, and low lymphocyte counts had an area under the curve (AUC) value of 0.930 with a sensitivity of 0.931 and a specificity of 0.784. The predictive model for mortality with NEWS2 Category III, cancer, and decreasing lymphocyte count had an AUC value of 0.883 with a sensitivity of 0.903 and a specificity of 0.701. A combined predictive model with bronchial asthma and low lymphocyte count, in contrast, had an AUC value of 0.768 with a sensitivity of 0.828 and a specificity of 0.719 for NEWS2 score (5 or above) at presentation. NEWS2 supplemented with comorbidity profile and lymphocyte count could help identify hospitalized young adults at risk of adverse COVID-19 outcomes.

Cohort profile: Indian Network of Population-Based Surveillance Platforms for Influenza and Other Respiratory Viruses among the Elderly (INSPIRE).

PURPOSE: We describe here a multicentric community-dwelling cohort of older adults (>60 years of age) established to estimate incidence, study risk factors, healthcare utilisation and economic burden associated with influenza and respiratory syncytial virus (RSV) in India. PARTICIPANTS: The four sites of this cohort are in northern (Ballabgarh), southern (Chennai), eastern (Kolkata) and western (Pune) parts of India. We enrolled 5336 participants across 4220 households and began surveillance in July 2018 for viral respiratory infections with additional participants enrolled annually. Trained field workers collected data about individual-level and household-level risk factors at enrolment and quarterly assessed frailty and grip strength. Trained nurses surveilled weekly to identify acute respiratory infections (ARI) and clinically assessed individuals to diagnose acute lower respiratory infection (ALRI) as per protocol. Nasal and oropharyngeal swabs are collected from all ALRI cases and one-fifth of the other ARI cases for laboratory testing. Cost data of the episode are collected using the WHO approach for estimating the economic burden of seasonal influenza. Handheld tablets with Open Data Kit platform were used for data collection. FINDINGS TO DATE: The attrition of 352 participants due to migration and deaths was offset by enrolling 680 new entrants in the second year. All four sites reported negligible influenza vaccination uptake (0.1%-0.4%), low health insurance coverage (0.4%-22%) and high tobacco use (19%-52%). Ballabgarh had the highest proportion (54.4%) of households in the richest wealth quintile, but reported high solid fuel use (92%). Frailty levels were highest in Kolkata (11.3%) and lowest in Pune (6.8%). The Chennai cohort had highest self-reported morbidity (90.1%). FUTURE PLANS: The findings of this cohort will be used to inform prioritisation of strategies for influenza and RSV control for older adults in India. We also plan to conduct epidemiological studies of SARS-CoV-2 using this platform.

Outcomes of multisystem inflammatory syndrome in children temporally related to COVID-19: a longitudinal study.

To study the clinical, laboratory characteristics and outcomes of multisystem inflammatory syndrome in children (MIS-C) temporally related to coronavirus disease 2019 (COVID-19) in a resource-limited setting. All children meeting the World Health Organization case definition of MIS-C were prospectively enrolled. Baseline clinical and laboratory parameters were compared between survivors and non-survivors. Enrolled subjects were followed up for 4-6 weeks for evaluation of cardiac outcomes using echocardiography. The statistical data were analyzed using the stata-12 software. Thirty-one children with MIS-C were enrolled in an 11-month period. Twelve children had preexisting chronic systemic comorbidity. Fever was a universal finding; gastrointestinal and respiratory manifestations were noted in 70.9% and 64.3%, respectively, while 57.1% had a skin rash. Fifty-eight percent of children presented with shock, and 22.5% required mechanical ventilation. HSP like rash, gangrene and arthritis were uncommon clinical observations.The median duration of hospital stay was 9 (6.5-18.5) days: four children with preexisting comorbidities succumbed to the illness. The serum ferritin levels (ng/ml) [median (IQR)] were significantly higher in non-survivors as compared to survivors [1061 (581, 2750) vs 309.5 (140, 720.08), p value = 0.045]. Six patients had coronary artery involvement; five recovered during follow-up, while one was still admitted. Twenty-six children received immunomodulatory drugs, and five improved without immunomodulation. The choice of immunomodulation (steroids or intravenous immunoglobulin) did not affect the outcome. Most children with MIS-C present with acute hemodynamic and respiratory symptoms.The outcome is favorable in children without preexisting comorbidities.Raised ferritin level may be a poor prognostic marker. The coronary outcomes at follow-up were reassuring.

Clinical Characterization and Genomic Analysis of Samples from COVID-19 Breakthrough Infections during the Second Wave among the Various States of India.

From March to June 2021, India experienced a deadly second wave of COVID-19, with an increased number of post-vaccination breakthrough infections reported across the country. To understand the possible reason for these breakthroughs, we collected 677 clinical samples (throat swab/nasal swabs) of individuals from 17 states/Union Territories of the country who had received two doses (n = 592) and one dose (n = 85) of vaccines and tested positive for COVID-19. These cases were telephonically interviewed and clinical data were analyzed. A total of 511 SARS-CoV-2 genomes were recovered with genome coverage of higher than 98% from both groups. Analysis of both groups determined that 86.69% (n = 443) of them belonged to the Delta variant, along with Alpha, Kappa, Delta AY.1, and Delta AY.2. The Delta variant clustered into four distinct sub-lineages. Sub-lineage I had mutations in ORF1ab A1306S, P2046L, P2287S, V2930L, T3255I, T3446A, G5063S, P5401L, and A6319V, and in N G215C; Sub-lineage II had mutations in ORF1ab P309L, A3209V, V3718A, G5063S, P5401L, and ORF7a L116F; Sub-lineage III had mutations in ORF1ab A3209V, V3718A, T3750I, G5063S, and P5401L and in spike A222V; Sub-lineage IV had mutations in ORF1ab P309L, D2980N, and F3138S and spike K77T. This study indicates that majority of the breakthrough COVID-19 clinical cases were infected with the Delta variant, and only 9.8% cases required hospitalization, while fatality was observed in only 0.4% cases. This clearly suggests that the vaccination does provide reduction in hospital admission and mortality.

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.

Evaluation of COVID-19 Antigen Fluorescence Immunoassay Test for Rapid Detection of SARS-CoV-2.

INTRODUCTION: Tests detecting SARS-CoV-2-specific antigen have recently been developed, and many of them are now commercially available. However, the real-world performance of these assays is uncertain; therefore, their validation is important. In this study, we have evaluated the performance of STANDARD F COVID-19 antigen fluorescence immunoassay (FIA) kit. METHODS: Nasopharyngeal samples collected from patients were subjected to the test as per manufacturer's instructions. The performance of the kit was compared with the gold standard real-time polymerase chain reaction. RESULTS: A total of 354 patients were tested with STANDARD F COVID-19 antigen FIA test kit. The overall sensitivity, specificity, positive predictive value, and negative predictive value of this test were found to be 38%, 99%, 96.2%, and 72%, respectively, with a diagnostic accuracy of 75.7%. CONCLUSION: STANDARD F COVID-19 antigen FIA showed high specificity and positive predictive value but low sensitivity and negative predictive value.

A case of neglected hepatorenal dysfunction during the COVID pandemic.

As the world fights with the Coronavirus, most of the hospitals are gearing up for the care of these patients. As most of the attention these days is being given on Coronavirus, the patients suffering from other clinical infections are being neglected. SARS-CoV-2 is being kept as the top differential in patients presenting with fever and respiratory distress. We hereby present a case of patient returning from Indonesia during the pandemic presenting with a history of hepatic, renal dysfunction with fever and cough. Due to the pandemic, the patient's fever and cough outweighed the hepatic and renal dysfunction, and the patient had to undergo dialysis before the final diagnosis of leptospirosis could be made.

Chloroquine nasal drops in asymptomatic & mild COVID-19: An exploratory randomized clinical trial.

Background & objectives: Chloroquine (CQN) administered as nasal drops has the potential to achieve much greater local tissue levels than with oral/systemic administration. This trial was undertaken to study the efficacy and safety profile of topical nasal administration of CQN drops in reducing viral load and preventing clinical progression in early COVID-19 infection. Methods: This randomized clinical trial was done with a sample size of 60. Reverse transcription-polymerase chain reaction (RT-PCR) confirmed asymptomatic patients or those with mild COVID-19 illness [National Early Warning Score (NEWS) ≤4] were included. Patients were randomized in a 1:1 manner. Control arm (standard supportive treatment, n=30) was compared with intervention arm (n=30) of standard treatment plus CQN eye drops (0.03%) repurposed as nasal drops administered six times daily (0.5 ml/dose) for 10 days. Outcome measures were adverse events and adherence; clinical progression and outcomes were measured by NEWS; sequential RT-PCR cycle threshold (Ct) values were also noted on days 0, 3, 7 and 10. Results: Nasal CQN was associated with local irritation in seven and non-compliance in one of 30 patients. Eleven patients were excluded due to enrolment error (2 - recovered; 9 - false-positive referral), and 49 patients were analyzed as per modified intention-to-treat analysis. Clinical recovery was noted as similar with 100 per cent asymptomatic by day seven in both arms. Virological outcomes also indicated similarly improving Ct values in both arms, and similar proportion of patients transitioning to non-infectivity by day 10 (controls - 19/25; nasal CQN - 15/24). Nine false-positive patients with enrolment error and day 0 RT-PCR negative were initially uninfected but had continuing COVID-19 exposure and treatment as per randomization. Patients receiving nasal CQN (n=5) demonstrated stable Ct values from day 0 to 10, while patients with no nasal CQN (n=4) demonstrated significant dip in Ct value indicating to infection (Ct<35) and infectivity (Ct<33). Interpretation & conclusions: The present study suggests to the potential of topical nasal CQN in the prevention of COVID-19 infection if administered before the infection is established. No significant differences in clinical or virological outcome were however, demonstrated in patients with mild but established illness.

Rapid chromatographic immunoassay-based evaluation of COVID-19: A cross-sectional, diagnostic test accuracy study & its implications for COVID-19 management in India.

Background & objectives: Coronavirus disease 2019 (COVID-19) has so far affected over 41 million people globally. The limited supply of real-time reverse transcription-polymerase chain reaction (rRT-PCR) kits and reagents has made meeting the rising demand for increased testing incompetent, worldwide. A highly sensitive and specific antigen-based rapid diagnostic test (RDT) is the need of the hour. The objective of this study was to evaluate the performance of a rapid chromatographic immunoassay-based test (index test) compared with a clinical reference standard (rRT-PCR). Methods: A cross-sectional, single-blinded study was conducted at a tertiary care teaching hospital in north India. Paired samples were taken for RDT and rRT-PCR (reference standard) from consecutive participants screened for COVID-19 to calculate the sensitivity and specificity of the RDT. Further subgroup analysis was done based on the duration of illness and cycle threshold values. Cohen's kappa coefficient was used to measure the level of agreement between the two tests. Results: Of the 330 participants, 77 were rRT-PCR positive for SARS-CoV-2. Sixty four of these patients also tested positive for SARS-CoV-2 by RDT. The overall sensitivity and specificity were 81.8 and 99.6 per cent, respectively. The sensitivity of RDT was higher (85.9%) in participants with a duration of illness ≤5 days. Interpretation & conclusions: With an excellent specificity and moderate sensitivity, this RDT may be used to rule in COVID-19 in patients with a duration of illness ≤5 days. Large-scale testing based on this RDT across the country would result in quick detection, isolation and treatment of COVID-19 patients.

Otolaryngologic Manifestation and Long-Term Outcome in Mild COVID-19: Experience from a Tertiary Care Centre in India.

This study endeavours to comprehensively the study the spectrum of ENT manifestations in mild and asymptomatic COVID-19 and observe the natural course of anosmia and dysgeusia consequent to SARS-Cov-2 infection. A prospective cohort study was undertaken at a tertiary care centre in India on admitted patients with RT-PCR proven COVID-19. Patients were included provided the baseline National Early Warning Score (NEWS) was less than 4. Patients were screened for ENT manifestations using a questionnaire at baseline, 7 days, 14 days and 28 days. 225 patients were included in the study. Of these complete data at 4 weeks was available for 210. Out of 145 patients with mild COVID-19 (asymptomatic = 80), ENT manifestations accounted for 66.2% of all symptoms. Smell and taste disturbance had an overall incidence of 20% and 45% of ENT manifestations. Temporal trends of the recovery rate of anosmia and dysgeusia were 53.6% and 66.7% at 2 weeks, respectively. Corresponding rates at 3 weeks were 89.29% and 86.7%, respectively. By the end of 4 weeks 96% of the patients had recovered completely. The incidence of anosmia and dysgeusia in this study parallels the rates reported from other Asian countries, albeit, lower than the rates quoted from the Western Hemisphere. We recommend structured reporting of all ENT manifestations especially smell and taste disturbances to accurately identify individuals infected with SARS-Cov-2.

SARS-CoV-2 RT-PCR profile in 298 Indian COVID-19 patients: a retrospective observational study.

BACKGROUND: despite being in the 5th month of pandemic, knowledge with respect to viral dynamics, infectivity and RT-PCR positivity continues to evolve. AIM: to analyse the SARS CoV-2 nucleic acid RT-PCR profiles in COVID-19 patients. DESIGN: it was a retrospective, observational study conducted at COVID facilities under AIIMS, New Delhi. METHODS: patients admitted with laboratory confirmed COVID-19 were eligible for enrolment. Patients with incomplete details, or only single PCR tests were excluded. Data regarding demographic details, comorbidities, treatment received and results of SARS-CoV-2 RT-PCR performed on nasopharyngeal and oropharyngeal swabs, collected at different time points, was retrieved from the hospital records. RESULTS: a total of 298 patients were included, majority were males (75·8%) with mean age of 39·07 years (0·6-88 years). The mean duration from symptom onset to first positive RT-PCR was 4·7 days (SD 3·67), while that of symptom onset to last positive test was 17·83 days (SD 6·22). Proportions of positive RT-PCR tests were 100%, 49%, 24%, 8·7% and 20·6% in the 1st, 2nd, 3rd, 4th and >4 weeks of illness. A total of 12 symptomatic patients had prolonged positive test results even after 3 weeks of symptom onset. Age > = 60 years was associated with prolonged RT-PCR positivity (statistically significant). CONCLUSION: this study showed that the average period of PCR positivity is more than 2 weeks in COVID-19 patients; elderly patients have prolonged duration of RT-PCR positivity and requires further follow up.