Corpus overview


MeSH Disease

Human Phenotype

Fever (11)

Anosmia (5)

Dyspnea (3)

Pneumonia (3)

Cough (3)


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    Dynamic Change of COVID-19 Seroprevalence SERO among Asymptomatic TRANS Population in Tokyo during the Second Wave

    Authors: Sawako Hibino; Kazutaka Hayashida; Andrew C Ahn; Yasutaka Hayashida; Julia Bielicki; Tim Roloff; Roland Bingisser; Christian Nickel; Nina Khanna; Sarah Tschudin; Andreas Widmer; Katharina Rentsch; Hans Pargger; Martin Siegemund; Daiana Stolz; Michael Tamm; Stefano Bassetti; Michael Osthoff; Manuel Battegay; Adrian Egli; Hans H Hirsch; Christine Goffinet; Florian Kurth; Martin Witzenrath; Maria Theresa Völker; Sarah Dorothea Müller; Uwe Gerd Liebert; Naveed Ishaque; Lars Kaderali; Leif Erik Sander; Sven Laudi; Christian Drosten; Roland Eils; Christian Conrad; Ulf Landmesser; Irina Lehmann

    doi:10.1101/2020.09.21.20198796 Date: 2020-09-23 Source: medRxiv

    Importance: Fatality rates related to COVID-19 in Japan have been low compared to Western Countries and have decreased despite the absence of lockdown. Serological tests SERO monitored across the course of the second wave can provide insights into the population-level prevalence SERO and dynamic patterns of COVID-19 infection MESHD. Objective: To assess changes in COVID-19 seroprevalence SERO among asymptomatic TRANS employees working in Tokyo during the second wave. Design: We conducted an observational cohort study. Healthy volunteers working for a Japanese company in Tokyo were enrolled from disparate locations to determine seropositivity against COVID19 from May 26 to August 25, 2020. COVID-19 IgM and IgG antibodies SERO were determined by a rapid COVID19 IgM/IgG test kit using fingertip blood SERO. Across the company, tests were performed and acquired weekly. For each participant, serology tests were offered twice, separated by approximately a month, to provide self-reference of test results and to assess for seroconversion and seroreversion. Setting: Workplace setting within a large company. Participants: Healthy volunteers from 1877 employees of a large Japanese company were recruited to the study from 11 disparate locations across Tokyo. Participants having fever HP fever MESHD, cough HP cough MESHD, or shortness of breath MESHD at the time of testing were excluded. Main Outcome(s) and Measure(s): Seropositivity rate (SPR) was calculated by pooled data from each two-weeks window across the cohort. Either IgM or IgG positivity was defined as seropositive. Changes in immunological status against SARS-CoV-2 were determined by comparing results between two tests obtained from the same individual. Results: Six hundred fifteen healthy volunteers (mean + SD 40.8 + 10.0; range 19-69; 45.7 % female TRANS) received at least one test. Seroprevalence SERO increased from 5.8 % to 46.8 % over the course of the summer. The most dramatic increase in SPR occurred in late June and early July, paralleling the rise in daily confirmed cases TRANS within Tokyo, which peaked on August 4. Out of the 350 individuals (mean + SD 42.5 + 10.0; range 19-69; 46.0 % female TRANS) who completed both offered tests, 21.4 % of those individuals who tested seronegative became seropositive and seroreversion was found in 12.2 % of initially seropositive participants. 81.1% of IgM positive cases at first testing became IgM negative in approximately one month. Conclusions and Relevance: COVID-19 infection MESHD may have spread widely across the general population of Tokyo despite the very low fatality rate. Given the temporal correlation between the rise in seropositivity and the decrease in reported COVID-19 cases that occurred without a shut-down, herd immunity may be implicated. Sequential testing for serological SERO response against COVID-19 is useful for understanding the dynamics of COVID-19 infection at the population-level.

    Retinal imaging study diagnoses a case of COVID-19

    Authors: Jorge Ruiz-Medrano; José Manuel Ortiz-Egea; José María Ruiz-Moreno

    doi:10.21203/ Date: 2020-09-23 Source: ResearchSquare

    Background: Hyper-reflective lesions at the level of ganglion cell (GCL) and inner plexiform retinal layers (IPL) by Optical Coherence Tomography (OCT) and cotton wool spots in the examination of the eye fundus have recently been described as findings in patients with COVID-19 infection MESHD.Case report: We report a case of a 42-year-old male TRANS anesthetist who treated COVID patients during the previous five weeks and suddenly debuted with a temporal relative scotoma HP scotoma MESHD in his left eye (OS); three weeks before, he presented with ageusia for several days. Best corrected visual acuity was 20/20 for OS; no discromatopsy or afferent pupillary defect MESHD were present. Visual field was performed, with no significant findings associated to the focal loss of sensitivity SERO referred by the patient. The anterior segment was unremarkable on slit lamp examination in both eyes. Fundus examination of the left eye showed no significant findings. A placoid, hyperreflective band at the level of GCL and IPL was visible in the temporal and nasal side of the fovea on OCT which spared the outer retina, at the time of diagnosis and at one month. A propharyngeal swab test for SARS-CoV-2 RNA, IgG and IgM ELISA SERO determinations were performed. Real-time reverse-transcriptase polymerase chain reaction (RT‐PCR) was negative. ELISA SERO testing and a third rapid antibody SERO detection test performed 7 days after the onset of symptoms TRANS were positive.Conclusions: Ocular signs and symptoms in COVID cases are rarely reported, but may be underestimated, especially those that affect the retina and occur in asymptomatic TRANS or paucisymptomatic cases. We present the first case of diagnosis of COVID-19 based on retinal ophthalmic examination. 

    Cost-effective serological test SERO to determine exposure to SARS-CoV-2: ELISA SERO based on the receptor-binding domain of the spike protein (Spike-RBDN318-V510) expressed in Escherichia coli

    Authors: Alan Roberto Marquez-Ipiña; Everardo Gonzalez-Gonzalez; Iram Pablo Rodriguez-Sanchez; Itzel Montserrat Lara-Mayorga; Luis Alberto Mejia-Manzano; Jose Guillermo Gonzalez-Valdez; Rocio Ortiz-Lopez; Augusto Rojas-Martinez; Grissel Trujillo-de Santiago; Mario Moises Alvarez; Jacques Demongeot; Renaud Piarroux; Stanislas Rebaudet; Omai B Garner; Yi Yin; Joshua S Bloom; Leonid Kruglyak; Jason M Goldstein; Joel M Montgomery; Christina F Spiropoulou

    doi:10.1101/2020.09.15.20195503 Date: 2020-09-18 Source: medRxiv

    Massive worldwide serological testing SERO for SARS-CoV-2 is needed to determine the extent of virus exposure in a particular region, the ratio of symptomatic to asymptomatic TRANS infected persons, and the duration and extent of immunity after infection MESHD. To achieve this aim, the development and production of reliable and cost-effective SARS-CoV-2 antigens is critical. Here, we report the bacterial production of the peptide S-RBDN318-V510, which contains the receptor binding domain of the SARS-CoV-2 spike protein. We purified this peptide using a straightforward approach involving bacterial lysis, his-tag mediated affinity chromatography, and imidazole-assisted refolding. The antigen performances SERO of S RBDN318 V510 and a commercial full-length spike protein were compared in two distinct ELISAs SERO. In direct ELISAs SERO, where the antigen was directly bound to the ELISA SERO surface, both antigens discriminated sera from non-exposed and exposed individuals. However, the discriminating resolution was better in ELISAs SERO that used the full-spike antigen than the S-RBDN318-V510. Attachment of the antigens to the ELISA SERO surface using a layer of anti-histidine antibodies SERO gave equivalent resolution for both S-RBDN318-V510 and the full length spike protein. Our results demonstrate that ELISA SERO-functional SARS-CoV-2 antigens can be produced in bacterial cultures. S-RBDN318-V510 is amenable to massive production and may represent a cost-effective alternative to the use of structurally more complex antigens in serological COVID-19 testing.

    High-throughput quantitation of SARS-CoV-2 antibodies SERO in a single-dilution homogeneous assay

    Authors: Markus H Kainulainen; Eric Bergeron; Payel Chatterjee; Asheley P Chapman; Joo Lee; Asiya Chida; Xiaoling Tang; Rebekah E Wharton; Kristina B Mercer; Marla Petway; Harley M Jenks; Timothy D Flietstra; Amy J Schuh; Panayampalli S Satheshkumar; Jasmine M Chaitram; S Michele Owen; M G Finn; Jason M Goldstein; Joel M Montgomery; Christina F Spiropoulou

    doi:10.1101/2020.09.16.20195446 Date: 2020-09-18 Source: medRxiv

    SARS-CoV-2 emerged in late 2019 and has since spread around the world, causing a pandemic of the respiratory disease COVID-19. Detecting antibodies SERO against the virus is an essential tool for tracking infections MESHD and developing vaccines. Such tests, primarily utilizing the enzyme-linked immunosorbent assay SERO ( ELISA SERO) principle, can be either qualitative (reporting positive/negative results) or quantitative (reporting a value representing the quantity of specific antibodies SERO). Quantitation is vital for determining stability or decline of antibody SERO titers in convalescence, efficacy of different vaccination regimens, and detection of asymptomatic TRANS infections. Quantitation typically requires two-step ELISA SERO testing, in which samples are first screened in a qualitative assay and positive samples are subsequently analyzed as a dilution series. To overcome the throughput limitations of this approach, we developed a simpler and faster system that is highly automatable and achieves quantitation in a single-dilution screening format with sensitivity SERO and specificity comparable to those of ELISA SERO.

    Sero-surveillance (IgG) of SARS-CoV-2 among Asymptomatic TRANS General population of Paschim Medinipur District, West Bengal, India(Conducted during last week of July and 1st week of August 2020) - A Joint Venture of VRDL Lab (ICMR), Midnapore Medical College & Hospital & Department of Health and Family Welfare,Govt. of West Bengal, Paschim Medinipur

    Authors: Parthasarathi Satpati; Saumya Sankar Sarangi; Kripasindhu Gantait; Sayantani Endow; Nimai Chandra Mandal; Panchanan Kundu; Subhadip Bhunia; Soham Sarangi; Vladimir Volynkin; Hermann Zellner; Rengul Cetin-Atalay; Maria Martin; Volkan Atalay; Makoto Miyara; Guy Gorochov; Amelie Guihot; Christophe Combadiere; Duraipandian Thavaselvam; Devendra Kumar Dubey; Paul Lin; Hila Shaim; Sean G Yates; David Marin; Indreshpal Kaur; Sheetal Rao; Duncan Mak; Angelique Lin; Qi Miao; Jinzhuang Dou; Ken Chen; Richard Champlin; Elizabeth J Shpall; Katayoun Rezvani

    doi:10.1101/2020.09.12.20193219 Date: 2020-09-14 Source: medRxiv

    Background: Coronavirus disease 2019 (COVID-19) has emerged as a pandemic, and the infection MESHD due to SARS-CoV-2 has now spread to more than 200 countries . Surveillance systems form the foundation stone of active case finding, testing and contact tracing TRANS, which are the key components of the public health response to this novel, emerging infectious disease MESHD . There is uncertainty about the true proportion of patients who remain asymptomatic TRANS or pre-symptomatic at a given time. As per the WHO-China Joint Monitoring Mission Report, and an analysis of 21 published reports, anywhere between 5 and 80 per cent of SARS CoV 2 infected MESHD patients have been noted to be asymptomatic TRANS. Whereas in India 4197563 cases are positive, in which in West Bengal total 180788 cases (4.04% of Cases of India) positive of COVID 19. In Paschim Medinipur (West Medinipur) district contributing total 5489 cases (3.03% cases of West Bengal). In this scenario, we want to know the status of IgG seroprevalence SERO of SARS CoV 2 among asymptomatic TRANS general population, so that we can determine the extent of infection of SARS CoV MESHD 2 in general population. Objectives: Primary Objective: To estimate the seroprevalence SERO for SARS CoV 2 infection MESHD in the general asymptomatic TRANS population at Paschim Medinipur District. Secondary Objectives: To estimate age TRANS and sex specific seroprevalence SERO. To determine the socio demographic risk factors for SARS CoV 2 infection MESHD; To determine the other risk factors like comorbidities, vaccination status, travel TRANS history, contact history etc.; To determine the durability of Immunity (IgG) conferred by natural infection of SARS-CoV-2 MESHD in individuals previously RTPCR positive. Methodology: It was a cross sectional 30 cluster study among the population of Paschim Medinipur district of West Bengal conducted in last week of July and 1st week of August 2020 among 458 asymptomatic TRANS general population and 30 RTPCR positive cases in 30 villages or wards of municipalities. 30 clusters were chosen from list of COVID 19 affected villages/wards of municipality as per PPS (Probability Proportional to Size) method. Results: Of the 458 asymptomatic TRANS general population,19 asymptomatic TRANS people found to be seropositive IgG for SARS CoV 2 with Mean or average total seropositivity rate of 4.15%. 19 Out of 30 (63.33%) RTPCR positive patients found Seronegative. Median of Days between RTPCR test and sero SERO negativity found was 60 with minimum 28 days to maximum 101 days and Range of 73 days and a standard deviation of 19.46. Among risk factors, the risk of having IgG is more in persons having Travel TRANS history with odds ratio of 2.99- 95%CI (1.17-7.65) with p-value- 0.02. Hydroxychloroquine prophylaxis with Odds ratio of 8.49- 95% CI(1.59-45.19) with p value - 0.003. Occupation as migrant labour with Odds ratio of 5.08- 95% CI(1.96-13.18) with p value of 0.001. H/O Chicken pox with Odds ratio of 2.15- 95% CI(0.59-7.79) with p value of 0.017. Influenza vaccinated with Odds ratio of 8.07 with 95% CI (0.8-81.48) with a p value of 0.036. Conclusion: Of the 458 asymptomatic TRANS general population,19 asymptomatic TRANS people found to be seropositive IgG for SARS-CoV-2 with Mean or average total seropositivity rate of 4.15%. 19 Out of 30 (63.33%) RTPCR positive patients found Seronegative. Median of Days between RTPCR test and sero SERO negativity found was 60 with minimum 28 days to maximum 101 days and Range of 73 days and a standard deviation of 19.46. Those having Travel TRANS History and having occupation MESHD as Migrant Labourer have significantly higher probability of getting infected with SARS-CoV-2. No role has been found of Hydroxychloroquine Medicines as Chemoprophylactic. No durable immunity conferred by natural infection with SARS-CoV-2 mean time to become seronegative after positive RTPCR test 60 days. So there is a chance of reinfection after average 2 months.

    Household transmission TRANS in people infected with SARS-CoV-2 (COVID-19) in Metropolitan Lima

    Authors: Yolanda Angulo-Bazán; Gilmer Solis; Joshi Acosta; Fany Cardenas; Ana Jorge; César Cabezas; Maria Jesus Alcaraz; Javier Buesa; Jesus Rodriguez-Diaz; Ron Geller; David Navarro; Maria Gabrani; Michal Rosen-Zvi

    doi:10.1101/2020.09.06.20189456 Date: 2020-09-09 Source: medRxiv

    Objective: Describe the characteristics of SARS-CoV-2 infection MESHD among household members with a confirmed primary case TRANS of COVID-19 in low burden districts in Metropolitan Lima. Materials and Methods: A retrospective, secondary database review study was conducted. The information was collected from an epidemiological surveillance activity in close contacts TRANS (co-inhabitants) in 52 households in Metropolitan Lima with only one member with COVID-19. A reevaluation was carried out in 10 households. Epidemiological and clinical variables were evaluated and its association with the result of the rapid serological test SERO (presence of IgG, IgM or both). Results: Secondary cases TRANS were found in 40 households, which represents an average of 49.9% identification per household. A secondary attack rate TRANS of 53.0% (125 cases) was found among cohabitants, with 77.6% of cases being symptomatic (symptomatic / asymptomatic TRANS ratio: 3.5). The presence of fever HP and / or chills HP was found in 40.0% of people with a positive result, followed by a sore throat, in 39.2%. Ageusia MESHD and anosmia HP anosmia MESHD were present in 22.4% and 20.8% of cases, respectively. A reevaluation in 40 family members TRANS 33.6 +/- 2.7 days after the first evaluation, show the persistence of positive IgM and IgG in the 20 positive cases in the first evaluation. Conclusion: Having a primary case TRANS of COVID-19 in home, the secondary attack rate TRANS of this infection MESHD is 53%; however, in a significant proportion of households evaluated there was no positive case, beyond the primary case TRANS. The epidemiological and clinical characteristics found in this case were in accordance with what has already been reported in other international series.

    Clinical Performance SERO Evaluation of a SARS-CoV-2 Rapid Antibody Test SERO for Determining Past Exposure to SARS-CoV-2

    Authors: Peter Findeisen; Hugo Stiegler; Eloisa Lopez-Calle; Tanja Schneider; Eva Urlaub; Johannes Hayer; Claudia Silke Zemmrich

    doi:10.1101/2020.09.01.20180687 Date: 2020-09-04 Source: medRxiv

    The true prevalence SERO and population seropositivity of SARS-CoV-2 infection MESHD remains unknown, due to the number of asymptomatic TRANS infections MESHD and limited access to high- performance SERO antibody tests SERO. To control the COVID-19 pandemic it is crucial to understand the true seroprevalence SERO, but not every region has access to extensive centralized PCR and serology testing. Currently available rapid antibody tests SERO lack the accuracy needed for recommendation by health authorities. To fill this gap, we analyzed and validated the clinical performance SERO of a new point-of-care SARS-CoV-2 Rapid Antibody SERO Assay, a chromatographic immunoassay SERO for qualitative detection of IgM/IgG antibodies SERO for use in near-patient settings. Analysis was performed using 42 Anti-SARS-Cov-2 positive (CoV+) and 92 Anti-SARS-Covid-2 negative (CoV-) leftover samples from before December 2019, using the Elecsys(R) Anti-SARS-CoV-2 as the reference assay. Analytical specificity was tested using leftover samples from individuals with symptoms of common cold collected before December 2019. The SARS-CoV-2 Rapid Antibody Test SERO was 100.0% (95% CI 91.59-100.00) sensitive and 96.74% (95% CI 90.77-99.32) specific with an assay failure rate of 0.00%. No cross-reactivity was observed against the common cold panel. Method comparison was additionally conducted by two external laboratories, using 100 CoV+/275 CoV- samples, also comparing whole blood SERO versus plasma SERO matrix. The comparison demonstrated for plasma SERO 96.00% positive/96.36% negative percent agreement with the Elecsys Anti-SARS-CoV-2 and overall 99.20% percent agreement between whole blood SERO and EDTA plasma SERO. The SARS-CoV-2 Rapid Antibody Test SERO demonstrated similar clinical performance SERO to the manufacturer's data and to a centralized automated immunoassay SERO, with no cross-reactivity to common cold panels.

    Insights into the practical effectiveness of RT-PCR testing for SARS-CoV-2 from serologic data, a cohort study

    Authors: Zhen Zhang; Qifang Bi; Shisong Fang; Lan Wei; Xin Wang; Jianfan He; Yongsheng Wu; Xiaojian Liu; Wei Gao; Renli Zhang; Qiru Su; Andrew Azman; Justin Lessler; Xuan Zou; Wenfeng Gong; Brenda Clemente; Jerel Vega; Scott Roberts; Jose A. Gonzalez; Marciano Sablad; Rodrigo Yelin; Wendy Taylor; Kiyoshi Tachikawa; Suezanne Parker; Priya Karmali; Jared Davis; Sean M Sullivan; Steve G. Hughes; Pad Chivukula; Eng Eong Ooi

    doi:10.1101/2020.09.01.20182469 Date: 2020-09-03 Source: medRxiv

    Background: Virologic detection of SARS-CoV-2 through Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) has limitations for surveillance. Serologic tests SERO can be an important complementary approach. Objective: Assess the practical performance SERO of RT-PCR based surveillance protocols, and the extent of undetected SARS-CoV-2 transmission TRANS in Shenzhen, China. Design: Cohort study nested in a public health response. Setting: Shenzhen, China; January-May 2020. Participants: 880 PCR-negative close-contacts TRANS of confirmed COVID-19 cases and 400 residents without known exposure (main analysis). Fifty-seven PCR-positive case contacts (timing analysis). Measurements: Virological testing by RT-PCR. Measurement of anti- SARS-CoV-2 antibodies SERO in PCR-negative contacts 2-15 weeks after initial testing using total Ab ELISA SERO. Rates of undetected infection MESHD, performance SERO of RT-PCR over the course of infection MESHD, and characteristics of seropositive but PCR-negative individuals were assessed. Results: The adjusted seropositivity rate for total Ab among 880 PCR-negative close-contacts TRANS was 4.1% (95%CI, 2.9% to 5.7%), significantly higher than among residents without known exposure to cases (0.0%, 95%CI, 0.0% to 1.0%). PCR-positive cases were 8.0 times (RR; 95% CI, 5.3 to 12.7) more likely to report symptoms than the PCR-negative individuals who were seropositive, but otherwise similar. RT-PCR missed 36% (95%CI, 28% to 44%) of infected close-contacts TRANS, and false negative rates appear to be highly dependent on stage of infection MESHD. Limitations: No serological data were available on PCR-positive cases. Sample size was limited, and only 20% of PCR-negative contacts met inclusion criteria. Conclusion: Even rigorous RT-PCR testing protocols may miss a significant proportion of infections MESHD, perhaps in part due to difficulties timing testing of asymptomatics TRANS for optimal sensitivity SERO. Surveillance and control protocols relying on RT-PCR were, nevertheless, able to contain community spread in Shenzhen.

    Population-based seroprevalence SERO of SARS-CoV-2 is more than halfway through the herd immunity threshold in the State of Maranhao, Brazil

    Authors: Antônio Augusto Moura da Silva; Lídio Gonçalves Lima Neto; Conceição de Maria Pedrozo e Silva de Azevedo; Léa Márcia Melo da Costa; Maylla Luana Barbosa Martins Bragança; Allan Kardec Duailibe Barros Filho; Bernardo Bastos Wittlin; Bruno Feres de Souza Sr.; Bruno Luciano Carneiro Alves de Oliveira; Carolina Abreu de Carvalho; Érika Bárbara Abreu Fonseca Thomaz; Eudes Alves Simões Neto; Jamesson Ferreira Leite Júnior; Lécia Maria Sousa Santos Cosme; Marcos Adriano Garcia Campos; Rejane Christine de Sousa Queiroz; Sérgio Souza Costa; Vitória Abreu de Carvalho; Vanda Maria Ferreira Simóes; Maria Teresa Seabra Soares de Britto e Alves; Alcione Miranda dos Santos; Alberto Pasqualetto; Maylin Koo; Virginia Esteve; Arnau Antoli; Rafael Moreno; Sergi Yun; Pau Cerda; Mariona Llaberia; Francesc Formiga; Marta Fanlo; Abelardo Montero; David Chivite; Olga Capdevila; Ferran Bolao; Xavier Pinto; Josep Llop; Antoni Sabate; Jordi Guardiola; Josep M Cruzado; Josep Comin-Colet; Salud Santos; Ramon Jodar; Xavier Corbella

    doi:10.1101/2020.08.28.20180463 Date: 2020-09-01 Source: medRxiv

    Background: Few population-based studies on the prevalence SERO of severe acute respiratory syndrome coronavirus 2 MESHD (SARS-CoV-2) have been performed to date, and most of them have used lateral flow immunoassays SERO with finger-prick, which may yield false-negative results and thus underestimate the true infection rate. Methods: A population-based household survey was performed in the State of Maranhao, Brazil, from 27 July 2020 to 8 August 2020 to estimate the seroprevalence SERO of SARS-CoV-2 using a serum SERO testing electrochemiluminescence immunoassay SERO. A three-stage cluster sampling stratified by four state regions was used. The estimates took clustering, stratification, and non-response into account. Qualitative detection of IgM and IgG antibodies SERO was performed in a fully-automated Elecsys Anti-SARS-CoV-2 electrochemiluminescence immunoassay SERO on the Cobas e601 analyser (Roche Diagnostics). Findings: A total of 3156 individuals were interviewed. Seroprevalence SERO of total antibodies SERO against SARS-CoV-2 was 40.4% (95%CI 35.6-45.3). Population adherence to non-pharmaceutical interventions was higher at the beginning of the pandemic than in the last month. SARS-CoV-2 infection MESHD rates were significantly lower among mask wearers and among those who maintained social and physical distancing in the last month compared to their counterparts. Among the infected, 62.2% had more than three symptoms, 11.1% had one or two symptoms, and 26.0% were asymptomatic TRANS. The infection MESHD fatality rate was 0.17%, higher for males TRANS and advanced age groups TRANS. The ratio of estimated infections MESHD to reported cases was 22.2. Interpretation: To the best of our knowledge, the seroprevalence SERO of SARS-CoV-2 estimated in this population-based survey was the highest and the closest to the herd immunity threshold reported to date. Our results suggest that the herd immunity threshold is not as low as 20%, but at least higher than or equal to around 40%. The infection MESHD fatality rate was one of the lowest reported so far, and the proportion of asymptomatic TRANS cases was low.

    Genetic testing and serological SERO screening for SARS-CoV-2 infection MESHD in a COVID-19 outbreak in a nursing facility in Japan

    Authors: Yong Chong; Naoki Tani; Hideyuki Ikematsu; Nobuto Terazawa; Hitoshi Nakashima; Nobuyuki Shimono; Koichi Akashi; Yosuke Tanaka

    doi:10.21203/ Date: 2020-08-23 Source: ResearchSquare

    Background: The Pandemic of coronavirus disease MESHD (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 MESHD (SARS-CoV-2), has critically impacted the spread of infection within nursing facilities. We evaluated the usefulness of genetic and serological tests SERO conducted during a COVID-19 outbreak in a nursing facility in Japan.Methods: After the first identification of SARS-CoV-2 infection MESHD, a comprehensive, facility- and/or unit-wide PCR testing from nasopharyngeal swabs was repeatedly performed in a three-unit facility including 99 residents with dementia HP dementia MESHD and 53 healthcare personnel. Additionally, PCR testing was conducted separately for residents and staff with fever HP fever MESHD of ≥37.5 oC. Facility-wide serological testing SERO, including rapid kit testing and quantitative assay, was conducted twice over 1 month apart.Results: A total of 322 PCR and 257 antibody tests SERO were performed. 37 (24.3%) of the 152 individuals (25/99 residents, 25.3%; 12/53 staff, 22.6%) were identified as PCR-positive. Seven residents died with a mortality of 7.1% (7/99). Among the 37 individuals, 10 (27.0%) were asymptomatic TRANS at the time of testing. PCR positivity was concentrated on one unit (Unit 1) (20/30 residents, 66.7%; 9/14 staff, 64.3%). The other units showed a limited spread of infection MESHD. In unit-wide and separate tests, PCR positivity detection was highly prevalent (22.9% and 44.4%, respectively) in Unit 1, compared with that in the other units. Serological testing SERO identified two additional infected residents with a negative PCR result and showed that no staff was newly identified as infected.Conclusions: Thorough PCR testing, in combination with comprehensive and separate tests, is critical for managing COVID-19 outbreaks in nursing facilities, particularly, in units considered an epicenter. Serological testing SERO is also beneficial for tracing contacts TRANS, confirming the number of infected individuals, and authorizing the termination of the outbreak.

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MeSH Disease
Human Phenotype

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