Rapid Decline of SARS-CoV-2 Viral Load in Single vs. Double-Dose (Short-Interval <6 Weeks) ChAdOx nCoV-19 Vaccinated Health-Care Workers.

The present work was carried out during the emergence of Delta Variant of Concern (VoC) and aimed to study the change in SARS CoV-2 viral load in Covishield vaccinated asymptomatic/mildly symptomatic health-care workers (HCWs) to find out the optimum isolation period. The SARS CoV-2 viral load was carried out in sequential samples of 55 eligible HCWs which included unvaccinated (UnV; n = 11), single-dose vaccinated (SDV, n = 20) and double-dose vaccinated [DDV, n = 24; short-interval (<6 weeks)] subjects. The mean load of envelope (E) gene on day 5 in SDV [0.42 × 105 copies/reaction] was significantly lower as compared to DDV [6.3 × 105 copies/reaction, P = 0.005] and UnV [6.6 × 105 copies/reaction, P = 0.001] groups. The rate of decline of SARS CoV-2 viral load in the initial 5 days of PCR positivity was significantly higher in SDV as compared to that in DDV (Mean log decline 0.39 vs. 0.19; P < 0.001). This was possibly due to interference of adenoviral immunity of first dose of adenovirus-vectored vaccine in double-dose vaccinated HCWs who had received vaccines within a shorter interval (<6 weeks).

Characteristics & outcomes of cancer patients with COVID-19: A multicentre retrospective study from India.

Background & objectives: High mortality has been observed in the cancer population affected with COVID-19 during this pandemic. We undertook this study to determine the characteristics and outcomes of cancer patients with COVID-19 and assessed the factors predicting outcome. Methods: Patients of all age groups with a proven history of malignancy and a recent diagnosis of SARS-CoV-2 infection based on nasal/nasopharyngeal reverse transcriptase (RT)-PCR tests were included. Demographic, clinical and laboratory variables were compared between survivors and non-survivors groups, with respect to observed mortality. Results: Between May 11 and August 10, 2020, 134 patients were included from the three centres and observed mortality was 17.1 per cent. The median age was 53 yr (interquartile range 39-61 yr) and thirty four patients (25%) were asymptomatic. Solid tumours accounted for 69.1 per cent and breast cancer was the most common tumour type (20%). One hundred and five patients (70.5%) had received chemotherapy within the past four weeks and 25 patients (19.3%) had neutropenia at presentation. On multivariate analysis, age [odds ratio (OR) 7.99 (95% confidence interval [CI] 1.18-54.00); P=0.033], haemoglobin [OR 6.28 (95% CI 1.07-37.04); P=0.042] neutrophil-lymphocyte ratio [OR 12.02 (95% CI 2.08-69.51); P=0.005] and baseline serum albumin [OR 18.52 (95% CI 2.80-122.27); P=0.002], were associated with higher mortality. Recent chemotherapy, haematological tumours type and baseline neutropenia did not affect the outcome. Interpretation & conclusions: Higher mortality in moderate and severe infections was associated with baseline organ dysfunction and elderly age. Significant proportion of patients were asymptomatic and might remain undetected.

Clinical characteristics & outcome of SARS-CoV-2 infected neonates presenting to paediatric emergency.

Background & objectives: Data on neonatal COVID-19 are limited to the immediate postnatal period, with a primary focus on vertical transmission in inborn infants. This study was aimed to assess the characteristics and outcome of COVID-19 in outborn neonates. Methods: All neonates admitted to the paediatric emergency from August 1 to December 31, 2020, were included in the study. SARS-CoV-2 reverse transcription- (RT)-PCR test was done on oro/nasopharyngeal specimens obtained at admission. The clinical characteristics and outcomes of SARS-CoV-2 positive and negative neonates were compared and the diagnostic accuracy of a selective testing policy was assessed. Results: A total of 1225 neonates were admitted during the study period, of whom SARS-CoV-2 RT-PCR was performed in 969. The RT-PCR test was positive in 17 (1.8%). Mean (standard deviation) gestation and birth weight of SARS-CoV-2-infected neonates were 35.5 (3.2) wk and 2274 (695) g, respectively. Most neonates (11/17) with confirmed COVID-19 reported in the first two weeks of life. Respiratory distress (14/17) was the predominant manifestation. Five (5/17, 29.4%) SARS-CoV-2 infected neonates died. Neonates with COVID-19 were at a higher risk for all-cause mortality [odds ratio (OR): 3.1; 95% confidence interval (CI): 1.1-8.9, P=0.03]; however, mortality did not differ after adjusting for lethal malformation (OR: 2.4; 95% CI: 0.7-8.7). Sensitivity, specificity, accuracy, positive and negative likelihood ratios (95% CI) of selective testing policy for SARS-CoV-2 infection at admission was 52.9 (28.5-76.1), 83.3 (80.7-85.6), 82.8 (80.3-85.1), 3.17 (1.98-5.07), and 0.56 (0.34-0.93) per cent, respectively. Interpretation & conclusions: SARS-CoV-2 positivity rate among the outborn neonates reporting to the paediatric emergency and tested for COVID-19 was observed to be low. The selective testing policy had poor diagnostic accuracy in distinguishing COVID-19 from non-COVID illness.

Alternate Approach in Storing and Shipment of SARS-CoV-2 RNA Samples with the Use of FTA Cards.

Shipment of COVID-19 specimens within the country or overseas at long distances requires cold chain facility using dry ice and triple packing to prevent the risk of COVID-19 infection to the personnel involved in sample transport. The present study aimed to utilize FTA card technology as an alternate means of sample transport and storage across the country. Twenty-one SARS-CoV-2 lab confirmed samples with different Ct value (High, medium & low) were used to detect viral load in samples loaded on FTA card and further compared with VTM samples. The SARS-CoV-2 RNA was detected by rRT-PCR after storing for 14 days at 4 °C and 37 °C. The present study evaluated the utility of FTA cards for preserving the SARS CoV-2 RNA for 14-day period. A significant difference (P < 0.05) was observed in the cycle threshold (ΔCt 4-5) values obtained from FTA and VTM viral samples but it did not affect the positivity. The SARS-CoV-2 RNA could be recovered efficiently from FTA sample stored at 4 °C and 37 °C for 14 days. Thus, FTA cards could be an alternate option for transporting the samples at ambient temperature for a long time.

Clinico-Laboratory Profile, Intensive Care Needs and Short-Term Outcome of Multisystem Inflammatory Syndrome in Children (MIS-C): Experience during First and Second Waves from North India.

OBJECTIVES: To describe the clinico-laboratory profile, intensive care needs and outcome of multisystem inflammatory syndrome in children (MIS-C) during the first and second waves. METHODOLOGY: This retrospective study was conducted in the paediatric emergency and paediatric intensive care unit (PICU) of a tertiary care teaching hospital in North India involving 122 children with MIS-C admitted during the first wave (September 2020-January 2021, n = 40) and second wave (February 2021-September 2021, n = 82) of coronavirus disease 2019 (COVID-19). RESULTS: The median (interquartile range) age was 7 (4-10) years and 67% were boys. Common manifestations included fever (99%), abdominal symptoms (81%), rash (66%) and conjunctival injection (65%). Elevated C-reactive protein (97%), D-dimer (89%), procalcitonin (80%), IL-6 (78%), ferritin (56%), N-terminal pro B-type natriuretic peptide (84%) and positive severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibody (81%) were common laboratory abnormalities. Cardiovascular manifestations included myocardial dysfunction (55%), shock (48%) and coronary artery changes (10%). The treatment included intensive care support (57%), non-invasive (33%) and invasive (18%) ventilation, vasoactive drugs (47%), intravenous immunoglobulin (IVIG) (83%), steroids (85%) and aspirin (87%). The mortality was 5% (n = 6). During the second wave, a significantly higher proportion had positive SARS-CoV-2 antibody, contact with COVID-19 and oral mucosal changes; lower markers of inflammation; lower proportion had lymphopenia, elevated IL-6 and ferritin; lower rates of shock, myocardial dysfunction and coronary artery changes; lesser need of PICU admission, fluid boluses, vasoactive drugs and IVIG; and shorter hospital stay. CONCLUSION: MIS-C is a febrile multisystemic disease characterized by hyperinflammation, cardiovascular involvement, temporal relationship to SARS-CoV-2 and good outcome with immunomodulation and intensive care. During the second wave, the severity of illness, degree of inflammation, intensive care needs, and requirement of immunomodulation were less as compared to the first wave.

The clinical association between Periodontitis and COVID-19.

OBJECTIVES: The study aimed to clinically assess the association between periodontitis and COVID-19-related outcomes. MATERIAL AND METHODS: Data pertaining to patient demographics, medical history, blood parameters, periodontal clinical examination and aMMP-8 point-of-care diagnostics (both site-level and patient-level) was recorded for eighty-two COVID-19-positive patients. COVID-19-related outcomes such as COVID-19 pneumonia, death/survival, types of hospital admission and need of assisted ventilation were also assessed. RESULTS: Males were predominantly afflicted with COVID-19, with advanced age exhibiting a greater association with the presence of periodontitis. Higher severity of periodontitis led to 7.45 odds of requiring assisted ventilation, 36.52 odds of hospital admission, 14.58 odds of being deceased and 4.42 odds of COVID-19-related pneumonia. The aMMP-8 mouthrinse kit was slightly more sensitive but less specific than aMMP-8 site-specific tests. CONCLUSIONS: Based on the findings of the present study, periodontitis seems to be related to poorer COVID-19-related outcomes. However, within the constraints of this work, a direct causality may not be established. Periodontitis, by means of skewing the systemic condition for a number of comorbidities, may eventually influence COVID-19 outcomes in an indirect manner. CLINICAL RELEVANCE: The study is the first to clinically, and by means of a validated point-of-care diagnostic methodology, assess the association between periodontal health and COVID-19-related outcomes. Assessment of the periodontal status of individuals can aid in the identification of risk groups during the pandemic along with reinforcing the need to maintain oral hygiene and seeking periodontal care.

Excavating SARS-coronavirus 2 genome for epitope-based subunit vaccine synthesis using immunoinformatics approach.

Since the outbreak of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) in December 2019 in China, there has been an upsurge in the number of deaths and infected individuals throughout the world, thereby leading to the World Health Organization declaration of a pandemic. Since no specific therapy is currently available for the same, the present study was aimed to explore the SARS-CoV-2 genome for the identification of immunogenic regions using immunoinformatics approach. A series of computational tools were applied in a systematic way to identify the epitopes that could be utilized in vaccine development. The screened-out epitopes were passed through several immune filters, such as promiscuousity, conservancy, antigenicity, nonallergenicity, population coverage, nonhomologous to human proteins, and affinity with human leukocyte antigen alleles, to screen out the best possible ones. Further, a construct comprising 11 CD4, 12 CD8, 3 B cell, and 3 interferon-γ epitopes, along with an adjuvant ß-defensin, was designed in silico, resulting in the formation of a multiepitope vaccine. The in silico immune simulation and population coverage analysis of the vaccine sequence showed its capacity to elicit cellular, humoral, and innate immune cells and to cover up a worldwide population of more than 97%. Further, the interaction analysis of the vaccine construct with Toll-like receptor 3 (immune receptor) was carried out by docking and dynamics simulations, revealing high affinity, constancy, and pliability between the two. The overall findings suggest that the vaccine may be highly effective, and is therefore required to be tested in the lab settings to evaluate its efficacy.

Demographic & clinical profile of patients with COVID-19 at a tertiary care hospital in north India.

BACKGROUND & OBJECTIVES: The COVID-19 pandemic emerged as a major public health emergency affecting the healthcare services all over the world. It is essential to analyze the epidemiological and clinical characteristics of patients with COVID-19 in different parts of our country. This study highlights clinical experience in managing patients with COVID-19 at a tertiary care centre in northern India. METHODS: Clinical characteristics and outcomes of consecutive adults patients admitted to a tertiary care hospital at Chandigarh, India, from April 1 to May 25, 2020 were studied. The diagnosis of SARS-CoV-2 infection was confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) on throat and/or nasopharyngeal swabs. All patients were managed according to the institute's consensus protocol and in accordance with Indian Council of Medical Research guidelines. RESULTS: During the study period, 114 patients with SARS-CoV-2 infection were admitted. The history of contact with COVID-19-affected individuals was available in 75 (65.8%) patients. The median age of the patients was 33.5 yr (13-79 yr), and there were 66 (58%) males. Of the total enrolled patients, 48 (42%) were symptomatic. The common presenting complaints were fever (37, 77%), cough (26, 54%) and shortness of breath (10, 20.8%). Nineteen (17%) patients had hypoxia (SpO2<94%) at presentation and 36 (31%) had tachypnoea (RR >24). Thirty four (29.8%) patients had an accompanying comorbid illness. Age more than 60 yr and presence of diabetes and hypertension were significantly associated with severe COVID-19 disease. Admission to the intensive care unit (ICU) was needed in 18 patients (52%), with three (2.6%) patients requiring assisted ventilation. Mortality of 2.6 per cent (3 patients) was observed. INTERPRETATION & CONCLUSIONS: Majority of the patients with COVID-19 infection presenting to our hospital were young and asymptomatic. Fever was noted only in three-fourth of the patients and respiratory symptoms in half of them. Patients with comorbidities were more vulnerable to complications. Triaged classification of patients and protocol-based treatment resulted in good outcomes and low case fatality.

Absence of SARS-CoV-2 infection in the semen of men recovering from COVID-19 infection: An exploratory study and review of literature.

The effect of COVID-19 on the male reproductive tract has been sparsely studied. This exploratory study was designed to determine the presence of SARS-CoV-2 in the semen of men recovering from COVID-19. A systematic literature review was also performed as per PRISMA guidelines to gather perspective on this topic. The prospective study included men 21 years and older recovering from COVID-19 with nasopharyngeal swab negative for SARS-CoV-2 or at least two weeks from the last COVID RT-PCR positivity. After clinical evaluation, freshly ejaculated semen sample by masturbation was collected in a sterile container. Samples were processed for the detection of SARS-CoV-2 by RT-PCR. Twenty-one patients were contacted for the study, 11 of which consented to provide a semen sample. The mean age of the cohort was 29.72 ± 4.52 years. None of the patients gave a history of epididymo-orchitis or sexual dysfunction at the time of assessment. None of the semen samples demonstrated SARS-CoV-2 on RT-PCR. Median duration of semen sample collection from the COVID positivity was 44 days (Range 19-59 days). Detailed literature review revealed that SARS-CoV-2 is not found in patients recovering from COVID-19 infection. We conclude that SARS-CoV-2 is not found in the semen of patients recovering from COVID-19.

Intensive Care Needs and Short-Term Outcome of Multisystem Inflammatory Syndrome in Children (MIS-C): Experience from North India.

OBJECTIVES: To describe the intensive care needs and outcome of multisystem inflammatory syndrome in children (MIS-C). METHODOLOGY: This retrospective study was conducted in the pediatric emergency, pediatric intensive care unit (PICUs) and the coronavirus disease 2019 (COVID 19) hospital of a tertiary teaching and referral hospital in North India over a period of 5 months (September 2020 to January 2021). Clinical details, laboratory investigations, intensive care needs, treatment and short-term outcome were recorded. RESULTS: Forty children with median interquartile range age of 7 (5-10) years were enrolled. The common clinical features were fever (97.5%), mucocutaneous involvement (80%), abdominal (72.5%) and respiratory (50%) symptoms. Shock was noted in 80% children. Most cases (85%) required PICU admission where they received nasal prong oxygen (40%), non-invasive (22.5%) and invasive (22.5%) ventilation and vasoactive drug support (72.5%). The confirmation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) exposure was in the form of positive serology (66.7%), reverse transcriptase polymerase chain reaction (10%), and contact with SARS-CoV-2 positive case (12.5%). The common echocardiographic findings included myocardial dysfunction (ejection fraction <55%; 72.5%), and coronary artery dilatation or aneurysm (22.5%). The immunomodulatory treatment included intravenous immunoglobulin (2 g/kg) (100%) and steroids (methylprednisolone 10-30 mg/kg/day for 3-5 days) (85%). Aspirin was used in 80% and heparin (low molecular weight) in 7.5% cases. Two children died (5%) and median duration of PICU and hospital stay in survivors were 5 (2-8) and 7 (4-9) days, respectively. Children with shock showed higher total leucocyte count and higher rates of myocardial dysfunction. CONCLUSION: Cardiovascular involvement and shock are predominant features in severe disease. Early diagnosis can be challenging given the overlapping features with other diagnoses. A high index of suspicion is warranted in children with constellation of fever, mucocutaneous, gastrointestinal and cardiovascular involvement alongwith evidence of systemic inflammation and recent or concurrent SARS-CoV-2 infection. The short-term outcome is good with appropriate organ support therapies and immunomodulation.

Containment of varicella outbreak in intensive care unit of a tertiary level hospital.

BACKGROUND: Varicella-Zoster virus (VZV) infection in healthcare organizations, especially in intensive care units (ICU), having admitted immunocompromised patients, is of serious concern as well as poses threat to healthcare workers working in such critical areas. The present report defines the transmission and infection control measures initiated to curtail VZV infection spread in the trauma ICU of a tertiary care hospital of North India. OUTBREAK REPORT: At the infection outset, there were 12 patients admitted in ICU and 54 healthcare workers were posted to manage these critical patients. After confirmation of VZV infection, all susceptible patients as well as healthcare workers were quarantined and fresh intake of patients was restricted. Out of the total healthcare workers, 14 (25.92%) were found susceptible (as per protective VZV IgG titers) and were vaccinated. Of the 12 patients admitted in the ICU, six patients were discharged and sent home directly, four patients expired due to their critical disease state, one patient left against medical advice, and one patient remained admitted in ICU till the incubation period was over. Epidemiologically, line listing for index case reporting was done. The efficacy of control measures was re-evaluated to strengthen existing infection control practices and general measures viz. strict hand washing, adherence to aseptic protocols and intensification of environmental cleaning. CONCLUSIONS: Established varicella surveillance measures ensure VZV outbreaks are identified in a timely manner and control measures implemented to prevent further transmission. Also, vaccination policy among HCWs is the utmost requirement despite having huge financial implications.

No Traces of SARS-CoV-2 In Wounds of COVID-19 Positive Patients: A Pilot Study.

Background This study was performed to investigate the presence of SARS-CoV-2 virus in wounds of COVID-19 positive patients. Methods This is a single-center observational study. COVID-19 patients with wounds (traumatic/infective/surgical) were included in this study. Preoperative, intraoperative, or postoperative specimens were collected and analyzed with real-time reverse transcriptase polymerase chain reaction (rRT-PCR) to know the presence of the virus. Results A total of eight patients were included in this study. Eleven samples were collected (seven wound swabs, two peritoneal fluids, and two tissue specimens) and analyzed. None of the samples from the wound tested positive for the virus while they were tested positive for nasal swab taken simultaneously or within 3 days prior. Conclusion The wounds of COVID-19 patients are considered negative and can be managed with routine wound precautions.

A strategic approach to the synthesis of ferrocene appended chalcone linked triazole allied organosilatranes: Antibacterial, antifungal, antiparasitic and antioxidant studies.

A series of ferrocene appended chalcone allied triazole coupled organosilatranes (FCTSa 7-FCTSa 12) were synthesised with the aim of amalgamating the pharmacological action of the constituting moieties into a single molecular scaffold. All the synthesised silatranes were well characterized by various spectroscopic techniques like IR, 1H NMR, 13C NMR and elemental analysis. Organosilatranes were then evaluated for their biological alacrity against bacterial and fungal strains compared with the standard drugs Rifampicin and Amphotericin B respectively. The ferrocene conjugates were found to be only moderately effective against the tested microbes. However, the organosilatranes conceded excellent efficacy against parasite G. lamblia with FCTSa 11 arraying the leading results. On the other hand against another parasite T. vaginalis, FCTSa 8 has emerged as an outstanding composite. Further, Total Antioxidant Assay (TAA) with 2,2'-azino-bis-3-(ethylbenzothiazoline-6-sulphonic acid) revealed FCTSa 10 to be the best claimant for radical scavenging activity. Along these lines, introducing some different substituents in the synthesised hybrids may act as a useful strategy for increasing the biological profile of the drugs.

Genetic diversity of Plasmodium falciparum merozoite surface protein-1 (block 2), glutamate-rich protein and sexual stage antigen Pfs25 from Chandigarh, North India.

OBJECTIVE: To elucidate the genetic diversity of Plasmodium falciparum in residual transmission foci of northern India. METHODS: Clinically suspected patients with malaria were screened for malaria infection by microscopy. 48 P. falciparum-infected patients were enrolled from tertiary care hospital in Chandigarh, India. Blood samples were collected from enrolled patients, genomic DNA extraction and nested PCR was performed for further species confirmation. Sanger sequencing was carried out using block 2 region of msp1, R2 region of glurp and pfs25-specific primers. RESULTS: Extensive diversity was found in msp1 alleles with predominantly RO33 alleles. Overall allelic prevalence was 55.8% for RO33, 39.5% for MAD20 and 4.7% for K1. Six variants were observed in MAD20, whereas no variant was found in RO33 and K1 alleles. A phylogenetic analysis of RO33 alleles indicated more similarity to South African isolates, whereas MAD20 alleles showed similarity with South-East Asian isolates. In glurp, extensive variation was observed with eleven different alleles based on the AAU repeats. However, pfs25 showed less diversity and was the most stable among the targeted genes. CONCLUSION: Our findings document the genetic diversity among circulating strains of P. falciparum in an area of India with low malaria transmission and could have implications for control strategies to reach the national goal of malaria elimination.

Detailed investigation of ongoing subclinical hepatitis E virus infections; occurring in outbreak settings of North India.

BACKGROUND & AIMS: Every year globally WHO reports 20 million Hepatitis E virus (HEV) infections. The disease occurs as sporadic cases or focused outbreaks and has potentials to cause massive epidemics. The reservoir of HEV during inter-epidemic period is not well characterized. The sporadic cases usually lack history of contact with clinically overt HEV patients. In the present context we evaluated the occurrence of subclinical HEV as a possible reservoir in endemic region. METHODS: Blood samples were collected from 67 apparently healthy individuals and 10 acute viral hepatitis (AVH) patients during two HEV outbreaks in North India. The serum samples were tested for anti-HEV IgM, IgG, HEV-IgG avidity index, HEV viral load and conventional-PCR followed by sequencing and phylogenetic analysis. RESULTS: A total of 14 (20.89%) apparently healthy individuals showed the presence of anti-HEV IgM and IgG. Of 14 based on HEV-IgG avidity index, 9 (64.28%) had secondary-exposure, 4 (28.57%) had primary exposure, while one patient had intermediate avidity. Subclinical subjects with primary exposure had significantly higher anti-HEV IgM index as compared to secondary-exposure (P = 0.0028). Viral load in clinically jaundiced patients was significantly higher as compared to subclinical subjects (P < 0.0001). Phylogenetic analysis showed HEV sequences retrieved from subclinical individuals clustered along with AVH patients, suggesting matched source. The significantly low viral load in subclinical subjects hints towards the dose dependency for progression of clinical manifestation. CONCLUSION: We document subclinical HEV with low level viremia occurs during outbreak settings and goes un-noticed, which helps maintaining the virus in nature possibly leading to its endemicity.

Assessment of dried blood samples as an alternative less invasive method for detection of Hepatitis E virus marker in an outbreak setting.

Hepatitis E virus (HEV) is the causative agent of hepatitis E. It can be asymptomatic, associated with acute self-limiting hepatitis or acute liver failure. The conventional diagnosis of HEV infection relies on anti-HEV IgM serology. The collection of blood samples by venepunture for laboratory confirmation is often difficult during an outbreak. Thus, testing the specimens of dried blood spots (DBS) on filter papers can prove to be a feasible alternative. The present study aimed to evaluate the applicability of anti-HEV IgM detection from DBS samples and the stability of anti-HEV IgM detection at varied time interval, at various storage temperatures. Paired blood and DBS sample were collected from 44 jaundiced patients and eight healthy controls during HEV outbreaks. The DBS were tested for anti-HEV IgM by available ELISA kit with in-house modifications. Three cut offs were determined, that is, the CO1: kit cut-off, CO2: mean of negative controls above 3SD and CO3: area under Receiver operating Curve. The sensitivity of anti-HEV IgM detection ranged from 86-91%. The maximum sensitivity (91%) and specificity (100%) was obtained using CO3. Maximum stability of anti-HEV IgM antibodies (100%) was observed till 65 days at 4°C. Storage at 37°C significantly reduced anti-HEV IgM positivity, wherein 42.85% sample became negative by 45 days. DBS showed good sensitivity and specificity for detecting anti-HEV IgM and can be considered an alternate to serum sample. Moreover, anti-HEV IgM was stable at 4°C, which makes DBS a preferred method for storage and transportation of the sample to reference laboratory.

Effect of storage temperatures simulating transport conditions of nasopharyngeal swabs on the results of a chemiluminescence immunoassay (CLIA) to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen.

PURPOSE: Chemiluminescence Immunoassay (CLIA) is high throughput, rapid diagnostic test which has recently come up for the detection of SARS-CoV-2 antigen. The present study evaluated performance of CLIA antigen test in nasopharyngeal swab samples stored at different temperatures for 7 days to simulate the transport conditions and transit time across the country from remote peripheral laboratories to central facilities. MATERIALS AND METHODS: Limit of detection (LOD), sensitivity and specificity of VITROS® SARS-CoV-2 antigen assay was determined using Real-time reverse transcriptase PCR (rRT-PCR) confirmed SARS-CoV-2 positive and negative samples. To detect the effect of storage temperatures on VITROS ®SARS-CoV-2 antigen results, samples were stored at 4 â€‹°C, 25 â€‹°C & 37 â€‹°C for 7 days followed by detection of SARS-CoV-2 nucleocapsid antigen and compared with N-gene rRT-PCR. RESULTS: The VITROS® SARS-CoV-2 antigen test was found to have a sensitivity and specificity of 78.9% and 100% respectively with high sensitivity of 88.1% for samples with Ct â€‹< â€‹30. The LOD of VITROS assay was equivalent to 3800 copies of RNA per reactions as compared to 72 copies per reaction for rRT-PCR. We observed that more than 80% of samples with <30 Ct values could be detected by VITROS SARS-CoV-2 antigen assay at day 7 even when stored at 37 â€‹°C. For samples with Ct values between 26 and 30, on day 7 the positivity rate of N-antigen at 4 â€‹°C was 90.9% and 37 â€‹°C was 63.6%. CONCLUSIONS: CLIA testing can be carried out for the detection of SARS-CoV-2 N-protein in NP-swab samples transported in cold chain even with 7 days transit time, particularly for Ct â€‹< â€‹30 samples which represents cases with higher transmissibility. As drop in positivity for VITROS assay was lower as compared to rRT-PCR on day 7 in cold chain-maintained samples, the assay can be useful to screen samples received from remote peripheral areas before performing rRT-PCR.