Perspectives on Rapid Antigen Tests for Downstream Validation and Development of Theranostics.

Point-of-care SARS-CoV-2 rapid antigen tests have proven to be useful over the years and have become more apparent to the public eye during COVID-19 pandemic due to their ease of use, rapid processing and result times, and low cost. Here, we have assessed the effectiveness and accuracy of rapid antigen tests in comparison to the standard real-time polymerase chain reaction analyses of the same samples.

Clinical course, diagnosis, and management of bilateral COVID-19 associated conjunctivitis: A case study.

We present a rare case of COVID-19 associated conjunctivitis where patient presented with redness, foreign body sensation, watering, and pain. Symptoms started while patient was COVID-19 positive. On examination, severe conjunctival congestion was present along with follicles. Visual acuity was 6/6 in both eyes. The patient was started on topical antibiotics and showed improvement but again presented with aggravated symptoms. Conjunctival swab was sent for culture and sensitivity, which was negative for any organisms. The patient was then started on oral and topical steroid, which showed improvement. Even though COVID-19 associated conjunctivitis is self-limiting, here it showed a progressive course and resolved only after steroid.

Identification of the novel allele, HLA-A*01:01:01:92, in an individual from North India.

HLA-A*01:01:01:92 differs from HLA-A*01:01:01:01 by a single nucleotide G->C change at gDNA-56 position.

Seroprevalence of SARS-CoV-2 IgG antibody among healthy blood donors: a single centre study.

BACKGROUND: Severe acute respiratory syndrome corona virus 2(SARS-CoV-2), the causative agent of corona virus disease-2019(COVID- 19) which has led to a global pandemic. The true extent of the burden of COVID-19 may be underestimated, and there is need to know the current prevalence of SARS-CoV-2 antibody in population. METHODS: The present study was a cross-sectional study to assess prevalence of SARS-CoV- 2 IgG antibody among 586 healthy voluntary blood donors who donated whole blood between mid-December 2020 to January 2021. A chemiluminescence assay was used to detect the presence of SARS-CoV-2 IgG antibody in serum samples in addition to recommended transfusion transmitted infections tests and Signal to Cut Off (S/C) > 1 was considered as reactive for antibody as per manufacturer's instructions. RESULTS: In the present study, 586 healthy voluntary blood donors were enrolled and were screened for SARS- CoV-2 IgG antibody. Out of 586 donors, 52 donors had indeterminate values of SARS-CoV-2 IgG antibody. A total of 534 healthy voluntary blood donors' samples were included in the present study for analysis. Out of total 534 healthy blood donors, 42.88% (229) were found to be seropositive while 57.11% (305) were found to be seronegative. CONCLUSION: A 43% positivity of SARS-CoV-2 IgG antibody among healthy blood donors was detected which is an indication of presence of infection at community level and majority of the population already has been exposed to SARS-CoV-2 infection. However, there was no statistically significant association of type of blood group and age with seropositivity.

Correlation of sample-to-cut-off ratio of anti-SARS-CoV-2 IgG antibody chemiluminescent assay with neutralization activity: a prospective multi-centric study in India.

Background and Objectives: There are limited published data on association of results from commercial serological anti-SARS-CoV-2 IgG antibody CLIA (chemiluminescent immunoassay) assays with neutralizing antibodies. This study was undertaken with an objective to correlate sample-to-cut-off (S/Co) ratio of CLIA antibody tests with inhibition activity, which may then serve as a valuable guide for labelling plasma as COVID convalescent plasma (CCP) for therapy and assessing vaccine efficacy. Materials and Methods: A total of 139 donor serum samples who were previously RT-PCR positive and had recovered completely from COVID-19 at least 28 days prior to collection of samples were recruited at three sites. The samples were analysed for S/Co ratio and per cent inhibition activity with VITROS SARS-CoV-2 IgG chemiluminescent assay and GenScript cPass SARS-CoV-2 Surrogate Virus Neutralization Test (sVNT) kit, respectively. Linear regression equation and receiver operating characteristic (ROC) curve were used to check the proposed model of comparing S/Co with per cent inhibition. Results: The results indicate very good correlation between the S/Co ratio of the chemiluminescent IgG assay and the neutralization activity depicted by per cent inhibition on sVNT assay. S/Co ratio of 4·04 (low-titre) and 8·19 (high-titre) correlated with 30% and 68% inhibition, respectively. Conclusion: Chemiluminescent SARS-CoV-2 IgG assay can be used as a semi-quantitative test, with a cut-off of >8·19S/Co ratio for selecting donors for convalescent plasma therapy and assessing efficacy of vaccination.

The correlation of spurious eosinophilia in automated hematological analyzer Sysmex XS-800i with Plasmodium infection diagnosis.

CONTEXT: Automated analyzers based on flow cytometry have evolved as an effective adjuvant diagnostic tool in malaria diagnosis. AIM: To find out the correlation of interpretive (IP) message from automated hematology analyzer XS-800i and Plasmodium infection diagnosed in peripheral smear. SETTINGS AND DESIGN: Prospective study carried over a period of 2 years (July 2010 to June 2012). MATERIALS AND METHODS: All cases with IP message of eosinophilia in Sysmex XS-800i analyzer were screened for microscopic correlation of eosinophilia and other peripheral smear findings. RESULTS: In 24 out of 5012 patients with eosinophilia, microscopic eosinophil counts were normal. In these 24 cases, IP message in hematology analyzers was that the eosinophilia and WBC scattergram showed narrowed space between the eosinophil and neutrophil population. On careful examination of the peripheral smears of all 5012 cases, 39 cases revealed different stages of Plasmodium vivax (trophozoites, schizonts or gametocytes) in erythrocytes. CONCLUSION: Peripheral smears of the cases having inconsistent eosinophilia result with that of Sysmex XS-800i analyzer should be examined carefully for the presence of malaria parasites in the red blood cells. Sysmex XS-800i analyzers have moderate range of sensitivity and high degree of specificity in diagnosing malaria as spurious eosinophilia.