The present study was conducted from July 1, 2020 to September 25, 2020 in a dedicated coronavirus disease 2019 (COVID‐19) hospital in Delhi, India to provide evidence for the presence of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) virus in atmospheric air and surfaces of the hospital wards. Swabs from hospital surfaces (patient's bed, ward floor, and nursing stations area) and suspended particulate matter in ambient air were collected by a portable air sampler from the medicine ward, intensive care unit, and emergency ward admitting COVID‐19 patients. By performing reverse‐transcriptase polymerase chain reaction (RT‐PCR) for E‐gene and RdRp gene, SARS‐CoV‐2 virus was detected from hospital surfaces and particulate matters from the ambient air of various wards collected at 1 and 3‐m distance from active COVID‐19 patients. The presence of the virus in the air beyond a 1‐m distance from the patients and surfaces of the hospital indicates that the SARS‐CoV‐2 virus has the potential to be transmitted by airborne and surface routes from COVID‐19 patients to health‐care workers working in COVID‐19 dedicated hospital. This warrants that precautions against airborne and surface transmission of COVID‐19 in the community should be taken when markets, industries, educational institutions, and so on, reopen for normal activities.

BackgroundAntibody testing is often used for serosurveillance of coronavirus disease 2019 (COVID-19). Enzyme-linked immunosorbent assay and chemiluminescence-based antibody tests are quite sensitive and specific for such serological testing. Rapid antibody tests against different antigens are developed and effectively used for this purpose. However, their diagnostic efficiency, especially in real-life hospital setting, needs to be evaluated. Thus, the present study was conducted in a dedicated COVID-19 hospital in New Delhi, India, to evaluate the diagnostic efficacy of a rapid antibody kit against the receptor-binding domain (RBD) of the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).MethodsSixty COVID-19 confirmed cases by reverse transcriptase–polymerase chain reaction (RT-PCR) were recruited and categorized as early, intermediate, and late cases based on the days passed after their first RT-PCR–positive test report, with 20 subjects in each category. Twenty samples from pre-COVID era and 20 RT-PCR–negative collected during the study period were taken as controls. immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against the RBD of the spike (S) protein of SARS-CoV-2 virus were detected by rapid antibody test and compared with the total antibody against the nucleocapsid (N) antigen of SARS-CoV-2 by electrochemiluminescence-based immunoassay (ECLIA).ResultsThe detection of IgM against the RBD of the spike protein by rapid kit was less sensitive and less specific for the diagnosis of SARS-CoV-2 infection. However, diagnostic efficacy of IgG by rapid kit was highly sensitive and specific when compared with the total antibody against N antigen measured by ECLIA.ConclusionIt can be concluded that detection of IgM against the RBD of S protein by rapid kit is less effective, but IgG detection can be used as an effective diagnostic tool for SARS-CoV-2 infection in real-life hospital setting.

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Background Antibody testing are often used for serosurveillance of COVID-19. ELISA and Chemiluminesence based antibody test are quiet sensitive and specific for such serological testing. Rapid antibody tests are developed and effectively used for this purpose. But their diagnostic efficiency needs to be evaluated. So, the present study was conducted in a dedicated COVID-19 hospital in Delhi, India to evaluate the diagnostic efficacy of a Rapid antibody kit for COVID-19. Material and Method : Sixty COVID-19 confirmed cases by RT-PCR were recruited and categorized as early, intermediate and late cases based on the number of days of their first RT-PCR + ve tests, 20 subjects in each category. Twenty samples from pre-covid era were taken as controls. IgM and IgG antibodies against RBD of spike protein (S) of SARS-CoV2 virus were detected by Rapid antibody test and compared with total antibody against the nucleocapsid (N) antigen of SARS-CoV-2 by Electrochemiluminescence based Immunoassay (ECLIA). Results The detection IgM against Receptor binding domain (RBD) of spike protein by rapid kit was 0-37.5% sensitive and 0-100% specific for diagnosis of SARS-CoV-2 infection. However, efficacy of detection of IgG by rapid kit was 87–89% sensitive and 75–100% specific when compared with total antibody against N antigen measured by ECLIA based immunoassay. Conclusion It can be concluded that detection of IgM against RBD of S protein by rapid kit is not effective but IgG detection can be used as an effective diagnostic tool for SARS-COV-2 infection.