scholarly journals Regional Difference in Seroprevalence of SARS-CoV-2 in Tokyo: Results from the community point-of-care antibody testing

2020 ◽  
Author(s):  
Morihito Takita ◽  
Tomoko Matsumura ◽  
Kana Yamamoto ◽  
Erika Yamashita ◽  
Kazutaka Hosoda ◽  
...  
Keyword(s):  
Regional Difference ◽  
Point Of Care ◽  
Herd Immunity ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Community Based ◽  
Entire Cohort ◽  
Control And Prevention ◽  
Specific Igg ◽  
Polymerase Chain

AbstractThe serosurvey is an alternative way to know the magnitude of the population infected by coronavirus disease 2019 (COVID-19) since the expansion of capacity of the polymerase chain reaction (PCR) to detect the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was delayed. We herein report seroprevalence of COVID-19 accessed in the two community clinics in Tokyo. The point-of-care immunodiagnostic test was implemented to detect the SARS-CoV-2 specific IgG antibody in the peripheral capillary blood. The overall positive percentage of SARS-CoV-2 IgG antibody is 3.83% (95% confidence interval: 2.76-5.16) for the entire cohort (n =1,071). The central Tokyo of 23 special wards exhibited a significantly higher prevalence compared to the other area of Tokyo (p =0.02, 4.68% [95%CI: 3.08-6.79] versus 1.83 [0.68-3.95] in central and suburban Tokyo, respectively). The seroprevalence of the cohort surveyed in this study is low for herd immunity, which suggests the need for robust disease control and prevention. A community-based approach, rather than state or prefectural levels, is of importance to figure out profiles of the SARS-COV-2 outbreak.

scholarly journals Geographical Profiles of COVID-19 Outbreak in Tokyo: An Analysis of the Primary Care Clinic–Based Point-of-Care Antibody Testing

2020 ◽  
Vol 11 ◽  
pp. 215013272094269 ◽  
Author(s):  
Morihito Takita ◽  
Tomoko Matsumura ◽  
Kana Yamamoto ◽  
Erika Yamashita ◽  
Kazutaka Hosoda ◽  
...  
Keyword(s):  
Primary Care ◽  
Point Of Care ◽  
Herd Immunity ◽  
Primary Care Clinic ◽  
The Other ◽  
Cumulative Number ◽  
Antibody Testing ◽  
Care Clinic ◽  
Entire Cohort ◽  
Pcr Test

Introduction: The primary care clinic plays a major role in triage for coronavirus disease 2019 (COVID-19), where seroprevalence in the setting of primary care clinic remains less clear. As a point-of-care immunodiagnostic test for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the serosurvey represents an alternative to the polymerase chain reaction (PCR) test to measure the magnitude of COVID-19 outbreak in the communities lacking sufficient diagnostic capability for PCR testing. Methods: We assessed seropositivity for the SARS-CoV-2 IgG between April 21 and May 20, 2020, at 2 primary care clinics in Tokyo, Japan. Results: The overall positive percentage of SARS-CoV-2 IgG was 3.83% (95% confidence interval [CI]: 2.76-5.16) for the entire cohort (n = 1071). The 23 special wards of central Tokyo exhibited a significantly higher prevalence compared with the other areas of Tokyo after classification by residence ( P = .02, 4.68% [3.08-6.79] vs 1.83 [0.68-3.95] in central and suburban Tokyo, respectively). In central Tokyo, the southern area showed the highest seroprevalence compared with the other areas (7.92% [3.48-15.01]), corresponding to the cumulative number of confirmed COVID-19 patients by PCR test reported by the Tokyo Metropolitan Government. Conclusion: The seroprevalence surveyed in this study was too low for herd immunity, suggesting the need for robust disease control and prevention. A regional-level approach, rather than state- or prefectural-level, could be of importance in ascertaining detailed profiles of the COVID-19 outbreak.

scholarly journals Seroprevalence study of SARS-CoV-2 infection in General Practice in Ireland

BJGP Open ◽  
2021 ◽  
pp. BJGPO.2021.0038
Author(s):  
Michael Edmund O'Callaghan ◽  
Elizabeth Ryan ◽  
Cathal Walsh ◽  
Peter Hayes ◽  
Monica Casey ◽  
...  
Keyword(s):  
General Practice ◽  
Average Length ◽  
Point Of Care ◽  
Antibody Test ◽  
Igg Antibodies ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Seroprevalence Study ◽  
History Of ◽  
Pcr Test

Background: SARS-CoV-2 antibody testing in community settings may help us better understand the immune response to this virus and therefore help guide public health efforts. Aim: Conduct a seroprevalence study of IgG antibodies in Irish GP clinics. Design and Setting: Participants were 172 staff and 799 patients of 15 general practices in the Midwest region of Ireland. Methods: This seroprevalence study utilised 2 manufacturers’ point-of-care (POC) SARS-CoV-2 IgM-IgG combined antibody tests, offered to patients and staff in general practice from mid-June to mid-July 2020. Results: Immunoglobulin G (IgG) seroprevalence was 12.6% in patients attending general practice and 11.1% in staff working in general practice, with administrative staff having the lowest seroprevalence at 2.5% and nursing staff having the highest at 17.6%. Previous symptoms suggestive of SARS-CoV-2 and history of a polymerase chain reaction (PCR) test were associated with higher seroprevalence. IgG antibodies were detected in approximately 80% of participants who had a previous PCR-confirmed infection. Average length of time between participants’ positive PCR test and positive IgG antibody test was 83 days. Conclusion: Patients and healthcare staff in general practice in Ireland had relatively high rates of IgG to SARS-CoV-2 compared to the national average at the time (1.7%). Four-fifths of participants with a history of confirmed COVID-19 disease still had detectable antibodies an average of 12 weeks post-infection. While not proof of immunity, SARS-CoV-2 POC testing can be used to estimate IgG seroprevalence in general practice settings.

scholarly journals Functional SARS-CoV-2-specific immune memory persists after mild COVID-19

2020 ◽  
Author(s):  
Lauren B Rodda ◽  
Jason Netland ◽  
Laila Shehata ◽  
Kurt B Pruner ◽  
Peter M Morawski ◽  
...  
Keyword(s):  
T Cells ◽  
Herd Immunity ◽  
Immune Memory ◽  
Longitudinal Assessment ◽  
Igg Antibody ◽  
Global Pandemic ◽  
Specific Memory ◽  
Specific Igg ◽  
Ifn Γ ◽  
Memory Lymphocytes

The recently emerged SARS-CoV-2 virus is currently causing a global pandemic and cases continue to rise. The majority of infected individuals experience mildly symptomatic coronavirus disease 2019 (COVID-19), but it is unknown whether this can induce persistent immune memory that might contribute to herd immunity. Thus, we performed a longitudinal assessment of individuals recovered from mildly symptomatic COVID-19 to determine if they develop and sustain immunological memory against the virus. We found that recovered individuals developed SARS-CoV-2-specific IgG antibody and neutralizing plasma, as well as virus-specific memory B and T cells that not only persisted, but in some cases increased numerically over three months following symptom onset. Furthermore, the SARS-CoV-2-specific memory lymphocytes exhibited characteristics associated with potent antiviral immunity: memory T cells secreted IFN-γ and expanded upon antigen re-encounter, while memory B cells expressed receptors capable of neutralizing virus when expressed as antibodies. These findings demonstrate that mild COVID-19 elicits memory lymphocytes that persist and display functional hallmarks associated with antiviral protective immunity.

scholarly journals SARS-CoV-2 antigen and antibody prevalence among UK staff working with cancer patients during the COVID-19 pandemic.

2020 ◽  
Author(s):  
David M Favara ◽  
Karen McAdam ◽  
Anthony Cooke ◽  
Alex Bordessa-Kelly ◽  
Ieva Budriunaite ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Point Of Care ◽  
Nasopharyngeal Swab ◽  
Antibody Testing ◽  
Antibody Prevalence ◽  
Prevalence Trends ◽  
Department Staff ◽  
High Prevalence ◽  
Staff Group ◽  
Polymerase Chain

Background International guidelines for testing potentially immunosuppressed cancer patients receiving non-surgical anticancer therapies for SARS-CoV-2 (COVID-19) are currently lacking. The value of routinely testing staff treating cancer patients is not known. Methods: Patient-facing oncology department staff at work during the COVID-19 pandemic consented to have a nasopharyngeal swab SARS-CoV-2 antigen test by polymerase chain reaction (PCR) and blood tests for SARS-CoV-2 antibody using a laboratory Luminex-based assay and a rapid point-of-care (POC) assay on 2 occasions 28 days apart in June and July 2020. Results 434 participants were recruited: nurses (58.3%), doctors (21.2%), radiographers (10.4%) and administrators (10.1%). 82% were female; median age 40-years (range 19-66). 26.3% reported prior symptoms suggestive of SARS-CoV-2 infection and 1.4% tested PCR-positive prior to June 2020. All were PCR-negative at both study day 1 and 28. 18.4% were SARS-CoV-2 sero-positive on day 1 by Luminex, of whom 42.5% also tested positive by POC. 47.5% of Luminex sero-positives had antibodies to both nucleocapsid (N) and surface (S) antigens. Nurses (21.3%) and doctors (17.4%) had higher prevalence trends of Luminex sero-positivity compared with administrators (13.6%) and radiographers (8.9%) (p=0.2). 38% of sero-positive participants reported previous symptoms suggestive of SARS-CoV-2 infection, a 1.9-fold higher odds than sero-negative participants (p=0.01). 400 participants re-tested on day 28: 13.3% were Luminex sero-positive of whom 92.5% were previously positive and 7.5% newly positive. Nurses (16.5%) had the highest seroprevalence trend amongst staff groups (p=0.07). 32.5% of day 1 sero-positives became sero-negative by day 28: the majority being previously reactive to the N-antigen only (p<0.0001). Conclusion The high prevalence of SARS-CoV-2 IgG sero-positivity in oncology nurses, and the high decline of positivity over 4 weeks supports regular antigen and antibody testing in this staff group for SARS-CoV-2 as part of routine patient care prior to availability of a vaccine.

scholarly journals Corticosteroid injections during the COVID-19 pandemic

2020 ◽  
Vol 1 (9) ◽  
pp. 605-611 ◽  
Author(s):  
David McKean ◽  
Siok Li Chung ◽  
Rory Fairhead ◽  
Oliver Bannister ◽  
Malgorzata Magliano ◽  
...  
Keyword(s):  
Observational Study ◽  
Clinical Outcomes ◽  
Antibody Test ◽  
British Society ◽  
Rt Pcr ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Thoracic Imaging ◽  
Polymerase Chain ◽  
Corticosteroid Injections

Aims To describe the incidence of adverse clinical outcomes related to COVID-19 infection following corticosteroid injections (CSI) during the COVID-19 pandemic. To describe the incidence of positive SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) testing, positive SARS-COV2 IgG antibody testing or positive imaging findings following CSI at our institution during the COVID-19 pandemic. Methods A retrospective observational study was undertaken of consecutive patients who had CSI in our local hospitals between 1 February and 30June 2020. Electronic patient medical records (EPR) and radiology information system (RIS) database were reviewed. SARS-CoV-2 RT-PCR testing, SARS-COV2 IgG antibody testing, radiological investigations, patient management, and clinical outcomes were recorded. Lung findings were categorized according to the British Society of Thoracic Imaging (BSTI) guidelines. Reference was made to the incidence of lab-confirmed COVID-19 cases in our region. Results Overall, 1,656 lab-confirmed COVID-19 cases were identified in our upper tier local authority (UTLA), a rate of 306.6 per 100,000, as of 30June 2020. A total of 504 CSI injections were performed on 443 patients between 1 February and 30June 2020. A total of 11 RT-PCR tests were performed on nine patients (2% of those who had CSI), all of which were negative for SARS-CoV-2 RNA, and five patients (1.1%) received an SARS-CoV-2 IgG antibody test, of which 2 (0.5%) were positive consistent with prior COVID-19 infection, however both patients were asymptomatic. Seven patients (1.6%) had radiological investigations for respiratory symptoms. One patient with indeterminate ground glass change was identified. Conclusion The incidence of positive COVID-19 infection following corticosteroid injections was very low in our cohort and no adverse clinical outcomes related to COVID-19 infection following CSI were identified. Our findings are consistent with CSI likely being low risk during the COVID-19 pandemic. The results of this small observational study are supportive of the current multi-society guidelines regarding the judicious use of CSI. Cite this article: Bone Joint Open 2020;1-9:605–611.

scholarly journals Challenges of community point-of-care antibody testing for COVID-19 herd-immunity in Japan

QJM ◽  
2020 ◽  
Vol 113 (11) ◽  
pp. 785-786 ◽  
Author(s):  
M Takita ◽  
T Matsumura ◽  
K Yamamoto ◽  
E Yamashita ◽  
K Hosoda ◽  
...  
Keyword(s):  
Point Of Care ◽  
Herd Immunity ◽  
Antibody Testing

scholarly journals The use of dried blood spots for the serological evaluation of SARS-CoV-2 antibodies

2021 ◽  
Author(s):  
Zheng Quan Toh ◽  
Rachel A Higgins ◽  
Jeremy Anderson ◽  
Nadia Mazarakis ◽  
Lien Anh Ha Do ◽  
...  
Keyword(s):  
Dried Blood Spots ◽  
Strongly Correlated ◽  
Serum Samples ◽  
Igg Antibody ◽  
Seropositivity Rate ◽  
Hard To Reach Populations ◽  
Specific Igg ◽  
Polymerase Chain ◽  
Paired Serum ◽  
Serum Igg Levels

Abstract Background To determine if dried blood spot specimens (DBS) can reliably detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies, we compared the SARS-CoV-2 IgG antibody response in paired serum and eluates from DBS specimens. Methods A total of 95 paired DBS and serum samples were collected from 74 participants (aged 1–63 years) as part of a household cohort study in Melbourne, Australia. SARS-CoV-2 IgG antibodies specific for the receptor-binding domain (RBD) and S1 proteins between serum and eluates from DBS specimens were compared using an FDA-approved ELISA method. Results Among the 74 participants, 42% (31/74) were children and the rest were adults. A total of 16 children and 13 adults were SARS-CoV-2 positive by polymerase chain reaction. The IgG seropositivity rate was similar between serum and DBS specimens (18.9% (18/95) versus 16.8% (16/95)), respectively. Similar RBD and S1-specific IgG levels were detected between serum and DBS specimens. Serum IgG levels strongly correlated with DBS IgG levels (r = 0.99, P &lt; 0.0001) for both SARS-CoV-2 proteins. Furthermore, antibodies remained stable in DBS specimens for &gt;3 months. Conclusions DBS specimens can be reliably used as an alternative to serum samples for SARS-CoV-2 antibody measurement. The use of DBS specimens would facilitate serosurveillance efforts particularly in hard-to-reach populations and inform public health responses including COVID-19 vaccination strategies.

scholarly journals Preliminary Results of Seroprevalence of SARS-CoV-2 at Community Clinics in Tokyo

2020 ◽  
Author(s):  
Morihito Takita ◽  
Tomoko Matsumura ◽  
Kana Yamamoto ◽  
Erika Yamashita ◽  
Kazutaka Hosoda ◽  
...  
Keyword(s):  
Point Of Care ◽  
Cross Reactivity ◽  
Igg Antibody ◽  
Community Clinics ◽  
Diagnostic Pcr ◽  
Point Of Care Test ◽  
Positive Rate ◽  
Specific Igg ◽  
Novel Coronavirus ◽  
Low Sensitivity

AbstractSerological evaluation with SARS-CoV-2 specific IgG antibody will be an alternative way to know the pandemic of novel coronavirus disease (COVID-19) if the capacity for diagnostic PCR test is limited. The point-of-care test to detect SARS-CoV-2 specific IgG antibody in peripheral blood (n =202) was performed in two community clinics in Tokyo, Japan. The overall positive rate of SRAS-CoV-2 IgG antibody was 5.9% (95% confidence interval[CI]: 3.1-10.1). Higher rate was observed for healthcare workers (n =55, 9.1 [3.0-20.0]). The limitation on antibody tests includes low sensitivity and potent cross-reactivity with the previous coronavirus. Robust healthcare policy to efficiently monitor COVID-19 spread is warranted in Tokyo.

scholarly journals Persisting Salivary IgG against SARS-CoV-2 at 9 Months After Mild COVID-19: A Complementary Approach to Population Surveys

2021 ◽  
Author(s):  
Hassan Alkharaan ◽  
Shaghayegh Bayati ◽  
Cecilia Hellstrom ◽  
Annika Olsson ◽  
Karin Lindahl ◽  
...  
Keyword(s):  
Antibody Testing ◽  
Igg Antibody ◽  
Salivary Iga ◽  
Non Invasive ◽  
Complementary Approach ◽  
History Of ◽  
Specific Igg ◽  
Sparse Methods ◽  
Multiplex Bead

Background: Declining humoral immunity in COVID-19 patients and possibility of reinfections has raised concern. Mucosal immunity particularly salivary antibodies could be short-lived. However, long-term studies are sparse. Methods: Using a multiplex bead-based array platform, we investigated antibodies specific to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins in 256 saliva samples from convalescent patients 1-9 months after symptomatic COVID-19 (n=74, Cohort 1), undiagnosed individuals with self-reported questionnaires (n=147, Cohort 2), and individuals sampled pre-pandemic time (n= 35, Cohort 3). Results: Salivary IgG antibody responses in Cohort 1 (mainly mild COVID-19) were detectable up to 9 month recovery, with high correlations between spike and nucleocapsid specificity. At 9 months, IgG remained in saliva in majority as seen in blood serology. Salivary IgA was rarely detected at this timepoint. In Cohort 2, salivary IgG and IgA responses were significantly associated with recent history of COVID-19 like symptoms. Salivary IgG also tolerated temperature and detergent pre-treatments. Conclusions: Unlike SARS-CoV-2 salivary IgA that appeared short-lived, the specific IgG in saliva appears stable even after mild COVID-19 as noted for blood serology. The non-invasive saliva-based SARS-Cov-2 antibody testing with self-collection at homes may thus serve as a complementary alternative to conventional blood serology.

scholarly journals Australian mumps serosurvey 2012–2013: any cause for concern?

2020 ◽  
Vol 44 ◽  
Author(s):  
Cyra Patel ◽  
Frank Beard ◽  
Alexandra Hendry ◽  
Helen Quinn ◽  
Aditi Dey ◽  
...  
Keyword(s):  
Close Contact ◽  
Age Groups ◽  
Vaccine Dose ◽  
Population Level ◽  
Mmr Vaccine ◽  
Igg Antibody ◽  
Community Based ◽  
Weighted Estimates ◽  
Specific Igg ◽  
Specific Igg Antibodies

Objective To determine population-level immunity to mumps in Australia. Methods We tested randomly selected specimens from people aged 1–49 years using the Enzygnost anti-parotitis IgG enzyme immunoassay from an opportunistically collected serum bank in 2012–2013. Weighted estimates of the proportion seropositive and equivocal for mumps-specific IgG antibody were determined by age group and compared with two previous national serosurveys conducted in 2007–2008 and 1997–1998. Results Overall, 82.1% (95% CI 80.6–83.5%) of 2,729 specimens were positive or equivocal for mumps-specific IgG antibodies (71.1% positive [95% CI 69.4–72.9%]; 10.9% equivocal [95% CI 9.8–12.2%]). The proportion positive or equivocal was higher in 2012–2013 (82.1%) than in 2007–2008 (75.5%) and 1997–1998 (72.5%), but varied by age. The proportion positive or equivocal in 2012-2013 was above 80% for all age groups older than 1 year except for 30–34 year olds, corresponding to the 1978–1982 birth cohort previously identified as most likely to have missed out on a second MMR vaccine dose. Conclusions Seropositivity to mumps in 2012–2013 was well-maintained compared with previous serosurveys. Low mumps notifications over this period in Australia suggest an absence of community-based transmission of mumps infection in the general population, but recent outbreaks among Aboriginal adolescents and young adults in close-contact settings, despite high 2-dose MMR coverage, suggest that seroprotection may be insufficient in other similar settings in Australia.

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