scholarly journals High prevalence of SARS-CoV-2 antibodies in care homes affected by COVID-19; a prospective cohort study in England

2020 ◽  
Author(s):  
Shamez N Ladhani ◽  
Anna J Jeffery-Smith ◽  
Monika Patel ◽  
Roshni Janarthanan ◽  
Jonathan Fok ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Care Homes ◽  
Rt Pcr ◽  
Staff Members ◽  
Institutional Settings ◽  
High Prevalence ◽  
Almost All ◽  
Antibody Levels ◽  
Very High

Background: We investigated six London care homes experiencing a COVID-19 outbreak and found very high rates of SARS-CoV-2 infection among residents and staff. Here we report follow-up serological analysis in these care homes five weeks later. Methods: Residents and staff had a convalescent blood sample for SARS-CoV-2 antibody levels and neutralising antibodies by SARS-COV-2 RT-PCR five weeks after the primary COVID-19 outbreak investigation. Results: Of the 518 residents and staff in the initial investigation, 208/241 (86.3%) surviving residents and 186/254 (73.2%) staff underwent serological testing. Almost all SARS-CoV-2 RT-PCR positive residents and staff were antibody positive five weeks later, whether symptomatic (residents 35/35, 100%; staff, 22/22, 100%) or asymptomatic (residents 32/33, 97.0%; staff 21/22, 95.1%). Symptomatic but SARS-CoV-2 RT-PCR negative residents and staff also had high seropositivity rates (residents 23/27, 85.2%; staff 18/21, 85.7%), as did asymptomatic RT-PCR negative individuals (residents 62/92, 67.3%; staff 95/143, 66.4%). Neutralising antibody was present in 118/132 (89.4%) seropositive individuals and was not associated with age or symptoms. Ten residents (10/108, 9.3%) remained RT-PCR positive, but with lower RT-PCR cycle threshold values; all 7 tested were seropositive. New infections were detected in three residents and one staff member. Conclusions: RT-PCR testing for SARS-CoV-2 significantly underestimates the true extent of an outbreak in institutional settings. Elderly frail residents and younger healthier staff were equally able to mount robust and neutralizing antibody responses to SARS-CoV-2. More than two-thirds of residents and staff members had detectable antibodies against SARS-CoV-2 irrespective of their nasal swab RT-PCR positivity or symptoms status.

scholarly journals High Prevalence Of Antibody Response Against Plasmodium Falciparum (Pf) Antigens In A Holoendemic Area Of Benin (1994-1995)

2017 ◽  
Vol 13 (3) ◽  
pp. 306
Author(s):  
S. Judith Gbenoudon Satoguina ◽  
Clemens H. Cocken ◽  
Alan W. Thomas ◽  
Jean Langhorne ◽  
Ambaliou Sanni
Keyword(s):  
Malaria Vaccine ◽  
Antibody Responses ◽  
Antibody Prevalence ◽  
Data Set ◽  
Competition Elisa ◽  
Naturally Occurring ◽  
High Prevalence ◽  
Naturally Occurring Antibodies ◽  
Very High

The present study aimed at measuring the capacity of naturally occurring antibodies to bind Pf83/AMA-1 and MSP-1/19 antigens, two malaria vaccine candidates, in an immunoassay. According to the fact that antibody prevalence reflects endemicity of malaria, we further aimed at using the results obtained here as baseline data set to follow up and evaluate the expected decline in endemicity in 2016, 8 years after the change in drug policy in Benin. Therefore, individuals, 2 – 19 and above 20 years old, living in Awansori, a malaria holoendemic area in the suburb of Cotonou, Benin were bled during the dry and raining seasons of the years 1994/1995. Antibody responses were measured using direct, indirect and competition ELISA. We found a very high prevalence of antibody responses (89 to 96%) in the studied population. The results indicate for Pf83/AMA-1, that naturally occurring antibodies bind to protective epitopes in a competition ELISA with a parasite inhibiting monoclonal antibody. The data and samples analysed here were collected during the rainy season 1994 and the following dry season 1994/1995.

scholarly journals SARS-CoV-2 Neutralizing Antibody Levels Post COVID-19 Vaccination Based on ELISA Method—A Small Real-World Sample Exploration

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1139
Author(s):  
Xiaoguang Li ◽  
Chao Liang ◽  
Xiumei Xiao
Keyword(s):  
Neutralizing Antibodies ◽  
Detection Rate ◽  
Neutralizing Antibody ◽  
Population Characteristics ◽  
Detection Rates ◽  
Positive Detection Rate ◽  
Significant Difference ◽  
Positive Rate ◽  
Antibody Levels

This study investigated the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies following inoculation with the coronavirus disease (COVID-19) vaccine. From June to July 2021, 127 participants who had completed COVID-19 vaccination (inactivated SARS-CoV-2 vaccine, 64; CoronaVac, 61; CanSino, 2) were recruited and tested using SARS-CoV-2 neutralizing antibody kits. The positive detection rate (inhibition of neutralizing antibodies ≥ 30%) was calculated and stratified according to population characteristics and inoculation time. The positive rate of neutralizing antibody was 47.22% (17/36) in men and 53.85% (49/91) in women, and 54.55% (24/44) in BMI ≥ 24 and 50.60% (42/83) in BMI < 24. Age was stratified as 20–29, 30–39, 40–49, and ≥50; positive detection rates of SARS-CoV-2 neutralizing antibodies were observed in 60.00% (24/40), 50.00% (21/42), 48.39% (15/31), and 42.86% (6/14), respectively, but with no significant difference (x2 = 1.724, p = 0.632). Among 127 vaccinated participants, 66 (51.97%) were positive. The positive detection rate was 63.93% (39/61) with CoronaVac and 42.19% (27/64) with the inactivated SARS-CoV-2 vaccine (significance x2 = 5.927, p = 0.015). Multivariate analysis revealed a significant difference in vaccination times, with average vaccination weeks in the positive and negative groups of 11.57 ± 6.48 and 17.87 ± 9.17, respectively (t= −4.501, p < 0.001). The positive neutralizing antibody rate was 100.00%, 60.00%, 58.33%, 55.56%, 43.14%, 28.57%, and 0.00% at 2–4, 5–8, 9–12, 13–16,17–20, 21–24, and >24 weeks, respectively (x2 = 18.030, p = 0.006). Neutralizing antibodies were detected after COVID-19 inoculation, with differences relating to inoculation timing. This study provides a reference for vaccine evaluation and follow-up immunization strengthening.

Evaluation of Third-Party Deep Cleaning as a Listeria monocytogenes Control Strategy in Retail Delis

2017 ◽  
Vol 80 (11) ◽  
pp. 1913-1923 ◽  
Author(s):  
Susan R. Hammons ◽  
Andrea J. Etter ◽  
Jingjin Wang ◽  
Tongyu Wu ◽  
Thomas Ford ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Standard Operating Procedure ◽  
Third Party ◽  
Food Marketing ◽  
High Prevalence ◽  
Standard Operating ◽  
Before And After ◽  
Contact Surfaces ◽  
Very High

ABSTRACT The objective of this study was to develop and assess the efficacy of an aggressive deep cleaning sanitation standard operating procedure (DC-SSOP) in nine retail delicatessens to reduce persistent Listeria monocytogenes environmental contamination. The DC-SSOP was developed from combined daily SSOPs recommended by the Food Marketing Institute and input from experts in Listeria control from food manufacturing and sanitation. The DC-SSOP was executed by a trained professional cleaning service during a single 12-h shutdown period. A modified protocol from the U.S. Food and Drug Administration Bacteriological Analytical Manual was used to detect L. monocytogenes in samples from 28 food and nonfood contact surfaces that were collected immediately before and after each cleaning and in samples collected monthly for 3 months. The DC-SSOP significantly reduced L. monocytogenes prevalence overall during the 3-month follow-up period and produced variable results for persistent L. monocytogenes isolates. Six delis with historically low to moderate L. monocytogenes prevalence had no significant changes in the number of samples positive for L. monocytogenes after deep cleaning. Deep cleaning in very high prevalence delis (20 to 30% prevalence) reduced L. monocytogenes by 25.6% (Padj &lt; 0.0001, n = 294) overall during the follow-up period. Among delis with extremely high prevalence (&gt;30%), positive samples from nonfood contact surfaces were reduced by 19.6% (Padj = 0.0002, n = 294) during the follow-up period. The inability of deep cleaning to completely eliminate persistent L. monocytogenes was likely due to the diverse infrastructures in each deli, which may require more individualized intervention strategies.

scholarly journals Serum Antibody Response Comparison and Adverse Reaction Analysis in Healthcare Workers Vaccinated with the BNT162b2 or ChAdOx1 COVID-19 Vaccine

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1379
Author(s):  
Sung-Hee Lim ◽  
Seong-Hyeok Choi ◽  
Bora Kim ◽  
Ji-Youn Kim ◽  
Young-Sok Ji ◽  
...  
Keyword(s):  
Adverse Events ◽  
Antibody Response ◽  
Healthcare Workers ◽  
Serum Antibody ◽  
Neutralizing Antibody ◽  
And Gender ◽  
Gender Categories ◽  
Antibody Levels ◽  
Very High

The COVID-19 pandemic is changing rapidly and requires different strategies to maintain immunization. In Korea, different COVID-19 vaccines are recommended and available for various populations, including healthcare workers (HCWs) at high risk of SARS-CoV-2 infection. We plan to evaluate the adverse events (AEs) and immunogenicity of the BNT162b2 and ChAdOx1 vaccines in HCWs at a single center. This cohort study included HCWs fully vaccinated with either BNT162b2 or ChAdOx1. Blood samples were taken eight weeks after the second vaccination with both COVID-19 vaccines and six months after the second vaccination from participants with the BNT162b2 vaccine. The primary endpoint for immunogenicity was the serum neutralizing antibody responses eight weeks after vaccination. The secondary endpoint was the incidence of various AEs within 28 days of each vaccination. Between 16 March and 23 June 2021, 115 participants were enrolled (65 in the ChAdOx1 group and 50 in the BNT162b2 group). Significantly higher surrogate virus neutralization test (sVNT) inhibition was observed in participants vaccinated with two doses of BNT162b2 (mean (SD) 91.4 (9.68)%) than in those vaccinated with ChAdOx1 (mean (SD) 73.3 (22.57)%). The effectiveness of the BNT162b2 vaccine was maintained across all age and gender categories. At six months after the second dose, serum antibody levels declined significantly in the BNT162b2 group. The main adverse events, including fever, myalgia, fatigue, and headache, were significantly higher in the ChAdOx1 group after the first dose, whereas, after the second dose, those AEs were significantly higher in the BNT162b2 group (p < 0.05). Two doses of either the ChAdOx1 or the BNT162b2 COVID-19 vaccine resulted in very high seropositivity among the HCWs at our center. The quality of the antibody response, measured by sVNT inhibition, was significantly better with the BNT162b2 vaccine than with the ChAdOx1 vaccine. There was no significant association between neutralizing antibody response and AE after each vaccination in our cohort.

scholarly journals SARS-CoV-2 Seroprevalence in a Cohort of Asymptomatic, RT-PCR Negative Croatian First League Football Players

2020 ◽  
Author(s):  
Adriana Vince ◽  
Renata Zadro ◽  
Zvonimir Šostar ◽  
Sunčanica Ljubin Sternak ◽  
Jasmina Vraneš ◽  
...  
Keyword(s):  
Football Players ◽  
Professional Football ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Antibody Assay ◽  
Serum Samples ◽  
Staff Members ◽  
Paired Serum ◽  
Serology Testing

AbstractBackgroundDuring the COVID-19 pandemic the Croatian Football Federation has launched a new model of pre-season systematic examination of football players, emphasizing the diagnosis of asymptomatic SARS-CoV-2 infection and preventing further spread among the players.ObjectivesThe aim of this study was to assess the prevalence and dynamics of SARS-CoV-2 IgA and IgG antibodies in the cohort of asymptomatic and SARS-CoV-2 PCR negative professional football players in the Croatian First Football League by using a commercial ELISA antibody assay in the paired serum samples taken 2 months apart.MethodsSerology testing was performed from May till July 2020 in a cohort of 305 asymptomatic football players and club staff members. RT-PCR for detection of SARS-CoV-2 from nasopharyngeal swabs was performed on three occasions, and Euroimmun ELISA for detection of IgA and IgG (S1 and NCP) antibodies was tested in paired serum samples in May and July.ResultsAll RT-PCR results were negative. Sixty-one (20%) participants were reactive in one or two classes of antibodies at baseline and/or follow-up serology testing. IgA reactivity was found in 41 (13.4% [95% CI=10.7-17.7]) baseline sera and 42 (13.8% [95% CI=10.3-18.9]) follow-up sera. IgG to S1 protein was found in 6 (2% [95% CI=0.9-4.2]) participants at baseline and 1 (0.33% [95% CI=0.0006-1.83]) at follow-up. IgG to NCP was found in 2 (0.7% [95% CI=0.2-2.4]) participants at baseline and 8 (2.6% (95% CI=1.3-5.1]) participants at follow-up. Noticeable dynamics in the paired sera was observed in 18 (5.9%) participants (excluding borderline IgA results) or 32 (10.5%) (including IgA borderline results).ConclusionVarious patterns of IgA and IgG reactivity were found in the paired serum samples. Based on serology dynamics we estimate that in 5.9%-10.5% of PCR negative football players asymptomatic exposure to SARS-CoV-2 during pandemics could not be excluded.

scholarly journals Autism and COVID-19: A Case Series in a Neurodevelopmental Unit

2020 ◽  
Vol 9 (9) ◽  
pp. 2937
Author(s):  
Leslie Nollace ◽  
Cora Cravero ◽  
Alice Abbou ◽  
Brice Mazda-Walter ◽  
Alexandre Bleibtreu ◽  
...  
Keyword(s):  
Challenging Behaviors ◽  
Case Series ◽  
Rt Pcr ◽  
Community Based ◽  
Respiratory Dysfunction ◽  
Upper Respiratory Infection ◽  
Staff Members ◽  
Viral Spread ◽  
Close Cooperation

Background: COVID-19 has become pandemic and can impact individuals with autism as well. Here, we report a case series admitted to a neurobehavioral unit dedicated to challenging behaviors in patients with autism. Methods: We describe 16 patients (mean age 20.8 years; range 12–43 years; 76% male) with autism hospitalized between March 2020 and mid-April 2020 for challenging behaviors, for which COVID-19 disease has been suspected and who needed both psychiatric and medical care. A close cooperation with the Infectious and Tropical Diseases Department was organized to limit viral spread and training sessions (e.g., hygiene, clinical COVID-19 monitoring, virus testing) were given to staff members. Results: Most patients had severe autism and severe/moderate intellectual disability. Eleven patients were already in the unit when it was hit by the pandemic, and five were admitted from the community. Based on a virus search via reverse transcriptase polymerase chain reaction (RT-PCR) or serology at the 2-month follow-up, we had 11 confirmed COVID-19 cases. The main COVID-19 symptoms included benign upper respiratory infection signs (N = 9, 81.8%), diarrhea (N = 7, 63.6%), fatigue (N = 7, 63.6%), and respiratory signs (N = 5, 45.5%), including one patient who needed oxygen therapy. Three patients remained asymptomatic and COVID-19-free (including two under immunosuppressive treatments). Among the symptomatic patients, five showed atypical behaviors that we understood as idiosyncratic manifestations (e.g., irrepressible licking behavior). On day 14, only one patient with respiratory dysfunction still had a positive RT-PCR SARS-CoV-2 test. Conclusions: Organizing a COVID+ unit for patients with autism is realistic and requires close collaboration with infectologists. We believe that this initiative should be promoted to limit both the spread of the virus and the ostracism of patients with autism and challenging behaviors.

scholarly journals Persistence of rabies antibody 5 years after pre-exposure prophylaxis with human diploid cell antirabies vaccine and antibody response to a single booster dose

1987 ◽  
Vol 99 (1) ◽  
pp. 91-95 ◽  
Author(s):  
F. M. Rodrigues ◽  
V. B. Mandke ◽  
M. Roumiantzeff ◽  
C. V. R. Mohan Rao ◽  
J. M. Mehta ◽  
...  
Keyword(s):  
Antibody Response ◽  
Booster Dose ◽  
Neutralizing Antibody ◽  
Diploid Cell ◽  
Human Diploid Cell ◽  
Staff Members ◽  
Exposure Prophylaxis ◽  
Antibody Levels

SUMMARYIn 1978, 22 staff members of the National Institute of Virology, Pune, India, were given two doses of human diploid cell antirabies vaccine (HDCV) for primary pre-exposure prophylactic immunization; the interval between the two doses being approximately 4 weeks. Eighteen of these 22 vaccinees were given a booster dose 1 year later. All 18 vaccinees developed protective levels of antibody; most of them had antibody levels exceeding 10 IU/ml.In 1984, 5 years after the booster dose, 11 (79·0%) of 14 vaccinees tested still possessed neutralizing antibody levels ranging from 0·5 IU/ml to 10 IU/ml. Fourteen days after the administration of a booster dose, the antibody levels ranged from 10 to ≥ 100 IU/ml for all except one vaccinee (5·2 IU/ml). These findings demonstrate that the majority of vaccinees retained detectable neutralizing antibody after pre-exposure prophylaxis for as long as 5 years and that a single booster dose thereafter evoked a good antibody response.

scholarly journals Recombinant Nipah Virus Vaccines Protect Pigs against Challenge

2006 ◽  
Vol 80 (16) ◽  
pp. 7929-7938 ◽  
Author(s):  
Hana M. Weingartl ◽  
Yohannes Berhane ◽  
Jeff L. Caswell ◽  
Sheena Loosmore ◽  
Jean-Christophe Audonnet ◽  
...  
Keyword(s):  
Real Time ◽  
Nipah Virus ◽  
Neutralizing Antibody ◽  
Rt Pcr ◽  
Challenge Virus ◽  
Virus Shedding ◽  
Challenge Control ◽  
Human Infections ◽  
Antibody Levels

ABSTRACT Nipah virus (NiV), of the family Paramyxoviridae, was isolated in 1999 in Malaysia from a human fatality in an outbreak of severe human encephalitis, when human infections were linked to transmission of the virus from pigs. Consequently, a swine vaccine able to abolish virus shedding is of veterinary and human health interest. Canarypox virus-based vaccine vectors carrying the gene for NiV glycoprotein (ALVAC-G) or the fusion protein (ALVAC-F) were used to intramuscularly immunize four pigs per group, either with 108 PFU each or in combination. Pigs were boosted 14 days postvaccination and challenged with 2.5 × 105 PFU of NiV two weeks later. The combined ALVAC-F/G vaccine induced the highest levels of neutralization antibodies (2,560); despite the low neutralizing antibody levels in the F vaccinees (160), all vaccinated animals appeared to be protected against challenge. Virus was not isolated from the tissues of any of the vaccinated pigs postchallenge, and a real-time reverse transcription (RT)-PCR assay detected only small amounts of viral RNA in several samples. In challenge control pigs, virus was isolated from a number of tissues (104.4 PFU/g) or detected by real-time RT-PCR. Vaccination of the ALVAC-F/G vaccinees appeared to stimulate both type 1 and type 2 cytokine responses. Histopathological findings indicated that there was no enhancement of lesions in the vaccinees. No virus shedding was detected in vaccinated animals, in contrast to challenge control pigs, from which virus was isolated from the throat and nose (102.9 PFU/ml). Based on the data presented, the combined ALVAC-F/G vaccine appears to be a very promising vaccine candidate for swine.

scholarly journals Posttreatment Follow-Up of Helicobacter pylori Infection Using a Stool Antigen Immunoassay

2001 ◽  
Vol 8 (4) ◽  
pp. 718-723 ◽  
Author(s):  
Daniel E. Roth ◽  
David N. Taylor ◽  
Robert H. Gilman ◽  
Rina Meza ◽  
Uriel Katz ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Treatment Success ◽  
Eradication Therapy ◽  
Initial Assessment ◽  
Inclusion Criteria ◽  
High Prevalence ◽  
Stool Antigen ◽  
H Pylori ◽  
Very High

ABSTRACT The Helicobacter pylori stool antigen enzyme immunoassay (HpSA) was evaluated during posttreatment follow-up of patients in a country with a very high prevalence of H. pylori infection. From among 273 dyspeptic individuals (18 to 55 years) initially recruited from a shantytown in Lima, Peru, 238 participants who met the inclusion criteria and were suspected to beH. pylori positive based on 14C urea breath test (UBT) results underwent endoscopy. Participants with endoscopy-proven infections received standard eradication therapy and were monitored by UBT and HpSA at 1 month following treatment and at 3-month intervals for 9 months posttreatment. A second endoscopy was performed if UBT results showed evidence of treatment failure orH. pylori recurrence. Biopsy results were considered the “gold standard” in all analyses. Among patients who underwent endoscopy, HpSA had a pretreatment sensitivity of 93%. Two-hundred thirty patients completed the treatment regimen, of whom 201 (93%) were considered to have had successful treatment outcomes based on a negative follow-up UBT. Thirty-two patients with UBT-defined treatment failures or H. pylori recurrences at any point during the 9-month follow-up underwent a second endoscopy. In the posttreatment setting, HpSA had an overall sensitivity of 73% and a specificity of 67%. Agreement between UBT and HpSA diminished throughout the follow-up. Among 14 participants in whom HpSA remained positive at 1 month following treatment despite UBT evidence of treatment success, 12 (86%) became HpSA negative within 3 months posttreatment. Although this study confirmed the validity of the HpSA in the initial assessment of dyspeptic patients, the test demonstrated a reduced overall accuracy in the detection of treatment failures and H. pylorirecurrences during 9 months of posttreatment follow-up. Furthermore, in some patients it may take up to 3 months after successful eradication for antigen shedding to diminish to levels within the negative HpSA range.

Distinctive COVID-19 manifestations and re-exposure to SARS CoV 2 in clinical laboratory personnel under regular monitoring by RT-PCR and serology

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Fábio de Oliveira Martinez Alonso ◽  
◽  
Bruno Duarte Sabino ◽  
Marianna Tavares Venceslau ◽  
Rafael Brandão Varella ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Rt Pcr ◽  
Rna Detection ◽  
Laboratory Personnel ◽  
Regular Monitoring ◽  
Antibody Levels ◽  
Lack Of Knowledge

Clinical laboratory personnel (CLP) present a unique opportunity to investigate distinct forms of COVID-19 as they are under constant testing for SARS CoV 2 infection. SARS CoV 2 RNA and antibodies were routinely investigated over a 5-month period in 26 professionals from a clinical laboratory in RJ, Brazil. Of them, three (11.5%) CLP presented the following peculiar COVID-19 manifestations: 2/26 (7.7%) had SARS CoV 2 antibodies without RNA detection during the follow-up, with a possible re-exposure in one case, and 1/26 (3.8%) a confirmed reinfection with RNA detection, and possibly a third re-exposure. Based on a long follow-up of SARS CoV 2 infection in CLP, this study showed that cases of COVID-19 without RNA detection are not common, but it does indicate the risk of re-exposure after the fall of antibody levels. Although scarcely reported, the investigation of less frequent forms of COVID-19 is relevant, given the lack of knowledge of its impact on the pandemic.

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