1209. Seroprevalence of Measles, Mumps, and Rubella in Korean Healthcare Workers and Strategy for Vaccination

Abstract Background The measles, mumps, and rubella (MMR) vaccination to children was accelerated in South Korea as the National Immunization Programs in 1985. A two-dose MMR vaccination schedule was introduced in 1997. However, outbreaks of measles in healthcare institution continued to occur. Recent studies revealed that the seroprevalence of measles in healthcare workers (HCWs) was approximately 40–60% in twentieth. The purpose of this study was to determine the seroprevalence of MMR antibodies in HCWs to establish strategy for vaccination. Methods To prevent nosocomial transmission of measles, test for MMR antibody of HCWs was conducted in three teaching hospitals from January to February in 2019. The testing was conducted only in the patient contact departments. We excluded HCWs who did a history of vaccination after starting their work. Anti-measles IgG and anti-mumps IgG was detected using chemiluminescence immunoassay. Anti-rubella IgG was detected using chemiluninescence microparticle immunoassay. Equivocal value was treated as negative. We also compare the costs between strategies two-dose vaccination without antibody tests and vaccination after antibody testing. Results Total 598 HCWs were included in analysis. Of the HCWs tests, 92.6% were seropositive to measles, 86.6% to mumps, and 79.7% to rubella. In the linear regression analysis, the seropositive of measles and rubella antibodies was increased in proportion to age (β-coefficient 43.4, 95% CI 35.1–51.6, P < 0.001 and β-coefficient 10.2, 95% CI 7.2–13.2, respectively). But, the seropositive to mumps was not related to age (β-coefficient 2.6, 95% CI -5.4–10.7, P = 0.52). The HCWs who has seropositive to all MMR was 67.2%. It was highest in 1970th birthyear (77.1%) and lowest in 1980th birthyear (60.6%). It costs less 18,000 wons ($15.5) per HCWs in strategy of vaccination after antibody testing than two-dose vaccination without antibody testing. Conclusion Our data warrant the needs for routine antibody test for MMR, followed by MMR vaccination in Korean HCWS. We expect that this strategy can save costs and avoid unnecessary vaccination. Disclosures All authors: No reported disclosures.

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Accuracy of Rapid Point-of-Care Antibody Test in patients with suspected or confirmed COVID-19

10.1101/2020.11.17.20233296 ◽

2020 ◽

Author(s):

Rama Vancheeswaran ◽

Merlin L Willcox ◽

Beth Stuart ◽

Matthew Knight ◽

Hala Kandil ◽

...

Keyword(s):

Point Of Care ◽

Antibody Test ◽

Reference Laboratory ◽

List Type ◽

Reference Standard ◽

Point Of Care Test ◽

History Of ◽

Antibody Tests ◽

Composite Reference Standard ◽

Rapid Antibody

AbstractObjectivesTo assess the real-world diagnostic accuracy of the Livzon point-of-care rapid test for antibodies to SARS-COV-2DesignProspective cohort studySettingDistrict general hospital in EnglandParticipants173 Patients and 224 hospital staff with a history of COVID-19 symptoms, and who underwent PCR and/or reference antibody testing for COVID-19.InterventionsThe Livzon point-of-care (POC) lateral flow immunoassay rapid antibody test (IgM and IgG) was conducted at least 7 days after onset of symptoms and compared to the composite reference standard of PCR for SARS-COV-2 plus reference laboratory testing for antibodies to SARS-COV-2. The SARS-CoV-2 RT-PCR was tested using the available molecular technology during the study time (PHE laboratories, GeneXpert® system Xpert, Xpress SARS-CoV-2 and Source bioscience laboratory). All molecular platforms/assays were PHE/NHSE approved. The reference antibody test was the Elecsys Anti-SARS-CoV-2 assay (Roche diagnostics GmBH).Main outcome measuresSensitivity and specificity of the rapid antibody testResultsThe reference antibody test was positive in 190/268 (70.9%) of participants with a history of symptoms suggestive of COVID-19; in the majority (n=312) the POC test was taken 35 days or more after onset of symptoms. The POC antibody test had an overall sensitivity of 90.1% (292/328, 95% CI 86.3 – 93.1) and specificity of 100% (68/68, 95% CI 94.7 - 100) for confirming prior SARS-CoV-2 infection when compared to the composite reference standard. Sensitivity was 97.8% (89/92, 95% CI 92.3% to 99.7%) in participants who had been admitted to hospital and 84.4% (124/147, 95% CI 77.5% to 89.8%) in those with milder illness who had never been seen in hospital.ConclusionsThe Livzon point-of-care antibody test had comparable sensitivity and specificity to the reference laboratory antibody test, so could be used in clinical settings to support decision-making about patients presenting with more than 10 days of symptoms of COVID-19.What is already known on this topic-Presence of IgG and IgM antibodies to SARS-COV-2 indicates that the person was infected at least 7 days previously and is usually no longer infectious.-Rapid point-of-care tests for antibodies to SARS-COV-2 are widely available, cheap and easy to use-Preliminary evaluations suggested that rapid antibody tests may have insufficient accuracy to be useful for testing individual patients.What this study adds-The rapid point-of-care test for antibodies to SARS-COV-2 was 90.1% sensitive and 100% specific compared to reference standards for prior infection with COVID-19.-This is comparable to reference antibody tests-The point-of-care test evaluated in this study could be used to support clinical decision-making in real time, for patients presenting with symptoms of possible COVID-19 with at least 10 days of symptoms.

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

BJGP Open ◽

10.3399/bjgpo.2021.0038 ◽

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.

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Serosurveillance of SARS CoV 2 among the healthcare workers of a tertiary care teaching institution in Central Kerala during the post lockdown phase

10.1101/2021.01.27.21250502 ◽

2021 ◽

Author(s):

Aboobacker Mohamed Rafi ◽

Maglin Monica Lisa Joseph Tomy ◽

Ronnie Thomas ◽

Chithra Valsan ◽

U G Unnikrishnan ◽

...

Keyword(s):

United States ◽

Health Care ◽

Health Care Workers ◽

Healthcare Workers ◽

The United States ◽

P Value ◽

Antibody Testing ◽

Medical College ◽

Care Workers ◽

History Of

AbstractBackgroundKerala was the first state to have the confirmed case of COVID-19 in the country and it was first confirmed in Thrissur district on 30 January2020.Our institute being in the heart of the city had to take adequate measures to mitigate the spread and treat the required patients by keeping its staff safe & Healthy. The hallmark of COVID 19 infection is high infectivity, pre-symptomatic transmission and asymptomatic prevalence which could result in high cumulative numbers of infections, hospitalizations, and deaths. Kerala was the first state to confirm community transmission in July 2020.Health care workers being in the forefront in the war against COVID19 are very prone in acquiring the infection and are possible to be asymptomatic sources for cluster formation. Knowing the development of immunity as shown by the presence of anti COV2 antibodies in the population contributes to the epidemiological understanding of the disease. The intent of the study is to do an antibody testing in our hospital to find the serosurveillance of SARS CoV 2 among the healthcare workers in our hospital.AimTo estimate the seropositivity of SARS CoV 2 among the healthcare workers at Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, six months after revoking the lockdownMethodologyA cross sectional study among the health care workers of the medical college. Multistage Sampling was done with the hospital block as the first stage and departments as the second stage. In the final stage of sampling the test individuals were selected on a first come first served basis after the antibody test availability was declared open and free for all staff. A consent form and a Google form were given to all staff who volunteered for participating in the study. Each consented participant recruited into the investigation completed a questionnaire which covers details regarding demographics, exposure history, Residence & travel. Blood sample was collected and Anti-SARS COV2 IgG antibody testing which targets the Spike Protein 1(SP1) was done using the VITROS chemiluminescence platform (Orthoclinical diagnostics, USA). Sampling & testing ranged over a time frame from September 5th to December 15th, 2020ResultsJubilee Mission Medical College has 2785 working staff at the time of study. A total of 420 staff consented and their samples were tested. 37 staff members tested positive for COVID-19 antibody, yielding an overall prevalence of 8.75% (95% CI, 6.23–11.86). 86.5 % (32/37) of them were having a history of COVID-19 Antigen / RT PCR Positivity. We identified a statistically significant linear trend (p value =0.00001), between seropositivity and the degree of severity of COVID 19. Among the various factors which increase the risk of seroconversion, history of undergoing quarantine (p value < 0.001), contact with a confirmed case (p value = 0.002), contact with a caregiver for COVID 19 (p value =0.001) and history of Upper respiratory symptoms (p value =0.001), were found to be significantly associated with positive serology.ConclusionsThe overall seropositivity in the current study was found to be 8.75% which is comparable to seroprevalence studies conducted in the United States and Wuhan in China. The pattern of seropositivity across the different category of health workers observed in the present study showed a higher prevalence among nurses. This result is also in agreement with a recent published report from united states. Various measures advised by the national and state health authorities were adequately adhered to. Keeping track of the pattern of development of immunity in the community is part of understanding the illness and forecasting the spread. For the tested HCW, it will boost up morale by ending uncertainty. For the hospital administration it will help in decision making about relative focusing of interventions on patients in general and HCWs. By knowing the immunity status of HCWs, the Institution will be able to contribute authentically to the development of intervention strategies and guidelines from time to time, besides following the available guidelines. Being an educational institution, it is obligatory to train all the elements of care delivery to the future generation of health care workers. Getting experienced from a small but relevant sample was expected to facilitate larger community study envisaged in peripheral areas Jubilee served

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LB-12. SARS-CoV-2 RNA and Antibodies among People Experiencing Homelessness and Staying in Shelters or Outdoor Encampments in Denver, Colorado, May-July 2020

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa515.1909 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S849-S850

Author(s):

David McCormick ◽

Tracy Scott ◽

Jesse Chavez ◽

Kay Wilcox ◽

Grace E Marx ◽

...

Keyword(s):

Native American ◽

Venous Blood ◽

Antibody Test ◽

Sociodemographic Factors ◽

Mitigation Strategies ◽

Homeless Shelters ◽

Test Results ◽

Rt Pcr ◽

Antibody Testing ◽

Antibody Tests

Abstract Background The COVID-19 pandemic has disproportionately affected people experiencing homelessness (PEH) residing in shelters. Initial and regular testing of PEH in communities with moderate or substantial SARS-CoV-2 transmission may limit spread in shelters. We analyzed factors associated with positive SARS-CoV-2 RNA and antibody tests for PEH staying in shelters or encampments in Denver, Colorado. Methods In May 2020, Denver Public Health collaborated with local leaders to identify 4 homeless shelters and 3 outdoor encampments for voluntary, universal SARS-CoV-2 testing. At each testing event, a short questionnaire including sociodemographic factors and symptoms was administered to PEH who consented to testing. SARS-CoV-2 RNA testing by reverse transcription polymerase chain reaction (RT-PCR) was performed on nasopharyngeal swabs; antibody testing was performed on venous blood samples. PEH reporting a prior positive RT-PCR test were not retested but were eligible for antibody testing. Statistical calculations were performed with an α of 0.05; all tests were two-sided. Results From June 2–July 28, 2020, 931 PEH were approached. A total of 863 RT-PCR tests were performed at 14 testing events, and 334 antibody tests were performed at 5 testing events. Overall, 604 and 259 RT-PCR tests were conducted in 4 shelters and 3 encampments, respectively; 189 and 145 antibody tests were conducted in 3 shelters and 2 encampments, respectively. PEH tested in shelters were older, more often men, less often Native American, and less likely to report COVID-19 symptoms than those tested at encampments (Table 1). Overall, 9% of PEH tested in shelters tested positive for SARS-CoV-2 compared to 3% of PEH tested in encampments (p=0.002); 8% of men had positive RT-PCR results compared to 2% of women (p=0.03) (Table 2). PEH tested at shelters had a higher percentage of detectable SARS-CoV-2 antibodies than those tested in encampments (24% vs 8%, p=0.0002; Table 3). Neither RT-PCR nor antibody test results differed significantly by race or ethnicity. Table 1. Demographics of participants residing in encampments compared with shelters in Denver, Colorado, May-July 2020 (n=931) Table 2. Comparison of participants testing positive or negative for SARS-CoV-2 RT-PCR* by location and demographics, in Denver, Colorado, May-July 2020 Table 3. Comparison of participants testing positive or negative for antibodies against SARS-CoV-2 by location and demographics in Denver, Colorado, May-July 2020 Conclusion A greater percentage of PEH tested positive for both SARS-CoV-2 RNA and antibodies at shelters than encampments, suggesting that continued assessment of mitigation strategies in shelters should be a priority. Disclosures All Authors: No reported disclosures

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18 Socio-Demographic Associations of COVID Antibody in Multi-Ethnic Healthcare Workers

Age and Ageing ◽

10.1093/ageing/afab028.18 ◽

2021 ◽

Vol 50 (Supplement_1) ◽

pp. i1-i6

Author(s):

M Patel ◽

M Nair ◽

E Pirozzoli ◽

M C Cienfuegos ◽

E Aitken

Keyword(s):

Healthcare Workers ◽

Demographic Data ◽

Antibody Test ◽

Prevalence Rates ◽

Antibody Testing ◽

Cross Sectional ◽

Staff Members ◽

Healthcare Settings ◽

General Populations ◽

General Wards

Abstract Introduction Healthcare workers are particularly susceptible to developing COVID-19 owing to close and frequent contact with COVID-19 patients. This study aimed to describe prevalence of SARS-COV-2 antibodies amongst healthcare workers within a hospital trust and examine factors associated with increased prevalence of this antibody. Methods Data was obtained over a 4-week period in 2020 from a cross-sectional prospective survey of healthcare workers serving a multi-ethnic inner-city population who had IgG SARS-COV-2 antibody. Multiple, overlapping sources of notification were implemented to promote the availability of the test. Anonymised socio-demographic data about staff members were cross referenced with data of the antibody tests. Results Of 7,013,6,212 (89%) staff undertook the antibody test during the study period. The overall detection rate of IgG SARS COV-2 antibody was 26%(1584/6212). Univariate analyses reveal that there were no differences in the prevalence rates in terms of gender or age. Compared to white staff members (18%), prevalence of the antibody was significantly greater in Black(38%) and Asian(27%) staff members. The combined prevalence for all BAME staff members was 32%. The prevalence rates of staff in general wards (43%) were significantly higher other areas of the trust. For staff in emergency medicine, intensive care and anaesthetics, prevalence was 23%, whereas for other clinical teams it was 21%. In terms of professional groups, prevalence rates were highest amongst nursing and allied clinical services (28%), followed by doctors (23%), whereas, it was lower for non-clinical staff(19%). Discussion This large multi-ethnic hospital-based study has described the prevalence of recent exposure to SARS-COV-2 infection amongst healthcare workers and determined socio-demographic associations of this prevalence including ethnicity, professional healthcare groups, and geographical areas of work in healthcare settings. The study provides information that may be useful in future COVID studies examining the role of antibody testing both in general populations as well as in healthcare settings.

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SARS-CoV-2 infection in 86 healthcare workers in two Dutch hospitals in March 2020

10.1101/2020.03.23.20041913 ◽

2020 ◽

Cited By ~ 25

Author(s):

Marjolein F.Q. Kluytmans-van den Bergh ◽

Anton G.M. Buiting ◽

Suzan D. Pas ◽

Robbert G. Bentvelsen ◽

Wouter van den Bijllaardt ◽

...

Keyword(s):

Healthcare Workers ◽

Respiratory Symptoms ◽

Clinical Presentation ◽

Case Definition ◽

Northern Italy ◽

Teaching Hospitals ◽

Local Spread ◽

Clinical Presentations ◽

High Prevalence ◽

History Of

ABSTRACTBackgroundOn February 27, 2020, the first patient with COVID-19 was reported in the Netherlands. During the following weeks, nine healthcare workers (HCWs) were diagnosed with COVID-19 in two Dutch teaching hospitals, eight of whom had no history of travel to China or Northern-Italy. A low-threshold screening regimen was implemented to determine the prevalence and clinical presentation of COVID-19 among HCWs in these two hospitals.MethodsHCWs who suffered from fever or respiratory symptoms were voluntarily tested for SARS-CoV-2 by real-time reverse-transcriptase PCR on oropharyngeal samples. Structured interviews were conducted to document symptoms for all HCWs with confirmed COVID-19.FindingsThirteen-hundred fifty-three (14%) of 9,705 HCWs employed were tested, 86 (6%) of whom were infected with SARS-CoV-2. Most HCWs suffered from relatively mild disease and only 46 (53%) reported fever. Eighty (93%) HCWs met a case definition of fever and/or coughing and/or shortness of breath. None of the HCWs identified through the screening reported a travel history to China or Northern Italy, and 3 (3%) reported to have been exposed to an inpatient known with COVID-19 prior to the onset of symptoms.InterpretationWithin two weeks after the first Dutch case was detected, a substantial proportion of HCWs with fever or respiratory symptoms were infected with SARS-CoV-2, probably caused by acquisition of the virus in the community during the early phase of local spread. The high prevalence of mild clinical presentations, frequently not including fever, asks for less stringent use of the currently recommended case-definition for suspected COVID-19.RESEARCH IN PERSPECTIVEEvidence before this studyThis study was conducted in response to the global spread of SARS-CoV-2, and the detection of eight healthcare workers (HCWs) in two Dutch teaching hospitals within two weeks after the first patient with COVID-19 was detected in the Netherlands who had no history of travel to China or Northern-Italy, raising the question of whether undetected community circulation was occurring.Added value of this studyTo the best of our knowledge, this report is the first to describe the prevalence, the clinical presentation and early outcomes of COVID-19 in HCWs, which may be helpful for others seeking to identify HCWs suspected for COVID-19 in an outbreak situation.Implications of all the available evidenceWe describe that within two weeks after the first Dutch case was detected, a substantial proportion of HCWs with fever or (mild) respiratory symptoms were infected with SARS-CoV-2, probably caused by acquisition of the virus in the community during the early phase of local spread. The high prevalence of mild clinical presentations, frequently not including fever, asks for less stringent use of the currently recommended case-definition for suspected COVID-19.

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Evaluation of the Abbott Architect, Roche Elecsys and Virtus S1 SARS-CoV-2 antibody tests in community-managed COVID-19 cases

10.1101/2020.10.27.20220509 ◽

2020 ◽

Author(s):

Sebastian L. Johnston ◽

Paul F McKay ◽

Tatiana Kebadze ◽

Kai Hu ◽

Karnyart Samnuan ◽

...

Keyword(s):

Antibody Test ◽

Research Centre ◽

Strong Positive Correlation ◽

True Positive ◽

Antibody Testing ◽

Serum Samples ◽

True Negative ◽

Health And Social Care ◽

Antibody Tests ◽

Abbott Architect

AbstractBackgroundAntibody testing can help define how protective immunity to SARS-CoV-2 is and how long this immunity lasts. Many antibody tests have been evaluated in hospitalised rather than community based COVID-19 cases. Virtus Respiratory Research Ltd (Virtus) has developed its own quantitative IgM and IgG SARS CoV-2 antibody assay. We report its validation and performance characteristics and compare its performance with the Abbott Architect and Roche Elecsys assays in community COVID cases.MethodsWe developed a quantitative antibody test to detect IgM and IgG to the SARS-CoV-2 S1 spike protein (the Virtus test) and validated this test in 107 “true positive” sera from 106 community-managed and 1 hospitalised COVID-19 cases and 208 “true negative” serum samples. We validated the Virtus test against a neutralising antibody test. We determined sensitivities of the Abbott test in the 107 true positive samples and the Roche test in a subset of 75 true positive samples.ResultsThe Virtus quantitative test was positive in 93 of 107 (87%) community cases of COVID-19 and both IgM and IgG levels correlated strongly with neutralising antibody titres (r=0.75 for IgM, r=0.71 for IgG, P<0.0001 for both antibodies). The specificity of the Virtus test was 98.6% for low level antibody positives, 99.5% for moderate positives and 100% for high or very high positives. The Abbott test had a sensitivity of 68%. In the 75 sample subset, the Virtus test was positive in 91%, the Roche test in 69%.ConclusionsThe Abbott and Roche tests had sensitives of 68% and 69% respectively in this community set of COVID-19 sera, while the Virtus test had sensitivities of 87% and 91% in the same sample sets. The strong positive correlation with virus neutralization suggests a positive Virtus quantitative antibody test is likely predictive of protective against recurrent COVID-19.FundingThe development of the Virtus test and sample testing with all antibody tests was funded by Virtus Respiratory Research Ltd. The research studies providing 111 of the 208 of the “true negative” samples was supported by MRC Grant numbers MR/M025330/1 and G1100238 and by the National Institute of Health Research (NIHR) Imperial Biomedical Research Centre (BRC), SLJ is a NIHR Emeritus Senior Investigator and is funded in part by European Research Council Advanced Grant 788575 and the Asthma UK Clinical Chair (grant CH11SJ). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

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The protective effect of SARS-COV-2 antibodies in Scottish healthcare workers

ERJ Open Research ◽

10.1183/23120541.00080-2021 ◽

2021 ◽

pp. 00080-2021

Author(s):

Hani Abo-Leyah ◽

Stephanie Gallant ◽

Diane Cassidy ◽

Yan Hui Giam ◽

Justin Killick ◽

...

Keyword(s):

Healthcare Workers ◽

Local Population ◽

Antibody Test ◽

Asymptomatic Infection ◽

Rt Pcr ◽

Antibody Testing ◽

Natural Production ◽

Increased Risk ◽

Health And Social Care ◽

Almost All

BackgroundHealthcare workers (HCW) are believed to be at increased risk of SARS-CoV-2 infection. It is not known to what extent the natural production of antibodies to SARS-CoV-2 is protective against re-infection.MethodsA prospective observational study of HCW's in Scotland (UK) from May to September 2020. The Siemens SARS-CoV-2 total antibody assay was used to establish seroprevalence in this cohort. Controls, matched for age and sex to the general local population, were studied for comparison. New infections (up to 2/12/2020) post antibody testing were recorded to determine if the presence of SARS-CoV-2 antibodies protect against re-infection.ResultsA total of 2063 health and social care workers were recruited for this study. At enrolment 300 HCW had a positive antibody test (14.5%). 11/231 control sera tested positive (4.8%). HCW therefore had an increased likelihood of a positive test (Odds ratio 3.4 95% CI 1.85–6.16, p<0.0001). Dentists were most likely to test positive. 97.3% of patients who had previously tested positive for SARS-CoV-2 by RT-PCR had positive antibodies. 18.7% had an asymptomatic infection. There were 38 new infections with SARS-CoV-2 in HCW who were previously antibody negative and one symptomatic RT-PCR positive re-infection. The presence of antibodies was therefore associated with an 85% reduced risk of re-infection with SARS-CoV-2 (HR 0.15, 95% CI 0.06 to 0.35, p=0.026).ConclusionHCW were three times more likely to test positive for SARS-CoV-2 than the general population. Almost all infected individuals developed an antibody response which was 85% effective in protecting against re-infection with SARS-CoV-2.

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Seroprevalence of Mumps in Healthcare Workers in South Korea

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2020.1023 ◽

2020 ◽

Vol 41 (S1) ◽

pp. s387-s388

Author(s):

Sun Kyung Kim ◽

Jiwon Jung ◽

Sun Hee Kwak ◽

Min Jee Hong ◽

Eun Ok Kim ◽

...

Keyword(s):

South Korea ◽

Healthcare Workers ◽

Medical Center ◽

Tertiary Care ◽

Herd Immunity ◽

Antibody Test ◽

Care Hospital ◽

Birth Cohorts ◽

Antibody Testing ◽

Seropositivity Rate

Background: Mumps, a contagious disease, is transmissible by respiratory droplet particles and is preventable by vaccination. In South Korea, mandatory vaccination against mumps has markedly reduced its incidence. However, both the incidence and the number of reported cases of mumps have persistently increased in South Korea since 2007. Despite high vaccination rates, mumps outbreaks continue to occur, and many studies have been conducted on mumps seroprevalence in children and adolescents. In comparison, few reports have been published regarding mumps seroprevalence in healthcare workers (HCWs) in South Korea. Objective: We investigated the seroprevalence of HCWs in South Korea. Methods: This study was conducted at Asan Medical Center, a 2,705-bed tertiary-care hospital in Seoul, South Korea, with 8,329 HCWs. In 2018, we performed mumps antibody testing for HCWs. We administered MMR vaccination to all HCWs whose antibody test yielded equivocal or negative results. However, we did not repeat mumps antibody testing after MMR vaccination. Results: In total, 6,055 HCWs (73%) underwent mumps antibody testing. The overall mumps seropositivity rate was 87% (95% CI, 86%–87%). Seropositivity rates of all birth cohorts ranged from 72% to 92%. Mumps seropositivity rates were 88% in HCWs born before 1970, 87% in those born between 1970 and 1989, and 88% in those born between 1990 and 1995 (P = .59). Mumps seropositivity rates for both women and men HCWs were 87% (3,770 of 4,311 women and 1,517 of 1,744 men); the difference was not statistically significant (P = .62). The overall mumps seropositivity rate was 87%, which was above the herd immunity threshold of 75%–86%. Conclusions: Our results revealed that the overall mumps seropositivity rate in South Korean HCWs was above the herd immunity threshold. On the basis of this finding, we recommend that MMR vaccination after serologic testing may be a more reasonable approach than universal MMR vaccination alone in Korea.Funding: NoneDisclosures: None

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High Seroprevalence of Anti-SARS-CoV-2 Antibodies Among Ethiopian Healthcare Workers

10.21203/rs.3.rs-676935/v1 ◽

2021 ◽

Author(s):

Tesfaye Gelanew ◽

Berhanu Seyoum ◽

Andargachew Mulu ◽

Adane Mihret ◽

Markos Abebe ◽

...

Keyword(s):

Clinical Data ◽

Healthcare Workers ◽

Close Contact ◽

Addis Ababa ◽

Public Hospitals ◽

Sub Saharan Africa ◽

Enzyme Linked Immunosorbent Assay ◽

Antibody Testing ◽

African Countries ◽

History Of

Abstract BackgroundCOVID-19 pandemic has a devastating impact on the economies and health care system of sub-Saharan Africa. Healthcare workers (HWs), the main actors of the health system, are at higher-risk because of their occupation. Serology-based estimates of SARS-CoV-2 infection among HWs represent a measure of HWs’ exposure to the virus and a guide to the prevalence of SARS-CoV-2 in the community. This information is currently lacking in Ethiopia and other African countries. This study aimed to develop an in-house antibody testing assay, assess the prevalence of SARS-CoV-2 antibodies among Ethiopian high-risk frontline HWs.MethodsA cross-sectional seroprevalence study was conducted among HWs in five public hospitals located in different geographic regions of Ethiopia. Socio-demographic and clinical data were collected using questionnaire-based interviews. From consenting HWs, blood samples were collected between December 2020 and February 2021, the period between the two peaks of COVID-19 in Ethiopia. The collected sera were tested using an in-house immunoglobin G (IgG) enzyme-linked immunosorbent assay (ELISA) for SARS-CoV-2 specific antibodies on sera collected from HWs. Results Of 1,997 HWs who provided a blood sample, demographic and clinical data, 50.5% were female, 74.0% had no symptoms compatible with COVID-19, and 29.0% had history of contact with suspected or confirmed patient with SARS-CoV-2 infection. The overall seroprevalence was 39.6%. The lowest (24.5%) and the highest (48.0%) seroprevalence rates were found in Hiwot Fana Specialized Hospital in Harar and ALERT Hospital in Addis Ababa, respectively. Of the 821 seropositive HWs, 224(27.3%) had history of symptoms consistent with COVID-19. A history of close contact with suspected/confirmed COVID-19 cases was strongly associated with seropositivity (Adjusted odds Ratio (AOR) =1.4, 95% CI 1.1-1.8; p=0.015). ConclusionHigh SARS-CoV-2 seroprevalence levels were observed in the five Ethiopian hospitals. These findings highlight the significant burden of asymptomatic infection in Ethiopia, and may reflect the scale of transmission in the general population.

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