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Healthcare workers face a high risk of blood-borne infections due to needlestick injuries, especially in developing countries like Pakistan.This study aims to evaluate the prevalence of needlestick injuries, reporting practices, and post-exposure prophylaxis measures among healthcare personnel in tertiary care hospitals in Punjab.A cross-sectional study was conducted from May to July 2019. Data were collected from healthcare personnel working in teaching hospitals across six randomly selected cities of Punjab. Data were collected from 600 healthcare personnel using a pretested, self-administered questionnaire, employing stratified random sampling to ensure representative sampling. Descriptive statistics were applied, and differences in needlestick injuries across demographic segments were assessed using the Mann-Whitney U and Kruskal-Wallis H tests.Among the 600 respondents, 533 returned the complete questionnaire, yielding a response rate of 88.8%. The majority of respondents were female (n = 341, 64.2%). The mean years of service was 5.58 (±5.78), with most participants falling in the 0.5–5 years category (n = 338, 66.4%). The prevalence of self-reported needlestick injuries in the last six months was 35.25%. Most injuries occurred during sampling (n = 95, 35.85%), followed by recapping (n = 63, 23.77%). Reporting of needlestick injuries to the respective department was poor, with only 82 (21.87%) injuries reported. The frequency of needlestick injuries differed significantly across profession, working department, and education categories (p < 0.05). Sanitary staff were more likely to sustain needlestick injuries during garbage collection and waste handling. Post-exposure screening for blood-borne infections was received by 79 (42.93%) individuals, and post-exposure prophylaxis (PEP) was administered to 67 (36.41%).The high prevalence of needlestick injuries among healthcare personnel occurred primarily during sampling and recapping. Reporting of NSIs was inadequate, and post-exposure testing and prophylaxis practices were substandard. Enhanced policies and protocols are necessary for effective NSI surveillance and the administration of pre- and post-exposure prophylaxis. [ABSTRACT FROM AUTHOR]

Background: Leishmaniasis, caused by Leishmania spp. parasites, is an important zoonotic disease globally, posing severe threats to humans and animals. In the absence of effective vaccines, reliable serological diagnostic methods are critical for disease control. However, the enzyme-linked immunosorbent assay (ELISA) and immunochromatographic assay have limitations due to complexity, time required and/or sensitivity. Therefore, our objective was to develop an accurate, rapid and user-friendly detection method of canine leishmania antibody based on double-antigen sandwich homogeneous chemical luminescence. Methods: Homogeneous chemiluminescent technology was employed, and expressed recombinant fusion proteins containing full-length K9, K39 and K26 repeat sequences were used as diagnostic antigens. To establish a dual-antigen sandwich serological assay capable of detecting various antibody types, a factorial design was used to optimize concentrations of diagnostic antigen-receptor microspheres and of biotinylated diagnostic antigens, as well as of reaction solution composition and reaction duration. To evaluate and validate this newly developed method, we collected 41 Leishmania-positive serum samples, 30 Leishmania-negative control serum samples and 78 clinical serum samples for which no diagnostic information was available. Comparative analyses were performed using parasitological testing and an indirect ELISA as reference methods, focusing on diagnostic sensitivity and specificity. Results: Sodium dodecyl sulfate–polyacrylamide gel electrophoresis confirmed the purification of the diagnostic antigens, which exhibited clear bands without impurities. Based on results from the 41 Leishmania-positive samples and 30 Leishmania-negative samples, there was sufficient sensitivity to detect samples diluted up to 256-fold, with analytical specificity of 100%. Overall diagnostic sensitivity was 100% and diagnostic specificity was 93.3%. Diagnostic performance was highly consistent between the newly developed method and the indirect ELISA (Kappa = 0.82, P < 0.01). Testing could be completed within 35 min with the new method Conclusions: We have developed a novel double-antigen sandwich homogeneous chemical luminescence method to detect canine Leishmania antibodies, with high sensitively and specificity, a short incubation interval and a simple protocol. This streamlined approach not only offers a sensitive and efficient method for clinical diagnosis but also has great potential for use in automated testing. [ABSTRACT FROM AUTHOR]

Abstract Background Leishmaniasis, caused by Leishmania spp. parasites, is an important zoonotic disease globally, posing severe threats to humans and animals. In the absence of effective vaccines, reliable serological diagnostic methods are critical for disease control. However, the enzyme-linked immunosorbent assay (ELISA) and immunochromatographic assay have limitations due to complexity, time required and/or sensitivity. Therefore, our objective was to develop an accurate, rapid and user-friendly detection method of canine leishmania antibody based on double-antigen sandwich homogeneous chemical luminescence. Methods Homogeneous chemiluminescent technology was employed, and expressed recombinant fusion proteins containing full-length K9, K39 and K26 repeat sequences were used as diagnostic antigens. To establish a dual-antigen sandwich serological assay capable of detecting various antibody types, a factorial design was used to optimize concentrations of diagnostic antigen-receptor microspheres and of biotinylated diagnostic antigens, as well as of reaction solution composition and reaction duration. To evaluate and validate this newly developed method, we collected 41 Leishmania-positive serum samples, 30 Leishmania-negative control serum samples and 78 clinical serum samples for which no diagnostic information was available. Comparative analyses were performed using parasitological testing and an indirect ELISA as reference methods, focusing on diagnostic sensitivity and specificity. Results Sodium dodecyl sulfate–polyacrylamide gel electrophoresis confirmed the purification of the diagnostic antigens, which exhibited clear bands without impurities. Based on results from the 41 Leishmania-positive samples and 30 Leishmania-negative samples, there was sufficient sensitivity to detect samples diluted up to 256-fold, with analytical specificity of 100%. Overall diagnostic sensitivity was 100% and diagnostic specificity was 93.3%. Diagnostic performance was highly consistent between the newly developed method and the indirect ELISA (Kappa = 0.82, P

Background and Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) serosurveys are typically analysed by applying a fixed threshold for seropositivity ('conventional approach'). However, this approach underestimates the seroprevalence of anti‐nucleocapsid (N) in vaccinated individuals—who often exhibit a difficult‐to‐detect anti‐N response. This limitation is compounded by delays between the onset of infection and sample collection. To address this issue, we compared the performance of four immunoassays using a new analytical approach ('ratio‐based approach'), which determines seropositivity based on an increase in anti‐N levels. Materials and Methods: Two groups of plasma donors and four immunoassays (Elecsys total anti‐N, VITROS total anti‐N, Architect anti‐N Immunoglobulin G (IgG) and in‐house total anti‐N) were evaluated. First‐group donors (N = 145) had one positive SARS‐CoV‐2 polymerase chain reaction (PCR) test result and had made two plasma donations, including one before and one after the PCR test (median = 27 days post‐PCR). Second‐group donors (N = 100) had made two plasma donations early in the Omicron wave. Results: Among first‐group donors (97.9% vaccinated), sensitivity estimates ranged from 60.0% to 89.0% with the conventional approach, compared with 94.5% to 98.6% with the ratio‐based approach. Among second‐group donors, Fleiss's κ ranged from 0.56 to 0.83 with the conventional approach, compared with 0.90 to 1.00 with the ratio‐based approach. Conclusion: With the conventional approach, the sensitivity of four immunoassays—measured in a predominantly vaccinated population based on samples collected ~1 month after a positive test result—fell below regulatory agencies requirement of ≥95%. The ratio‐based approach significantly improved the sensitivities and qualitative agreement among immunoassays, to the point where all would meet this requirement. [ABSTRACT FROM AUTHOR]

SCIENTIFIC RELEVANCE. The sanctions currently imposed on the Russian Federation requireusing Russian diagnostic products in vaccine quality assessments, as well as searching for alternative testing methods, in particular, serological ones.AIM. This study aimed to demonstrate the possibility of using alternative serological methods, including immunoenzymatic, direct agglutination, and indirect haemagglutination methods, for the identification of tularaemia and brucellosis vaccines in studies and quality assessments.MATERIALS AND METHODS. This study used the established pharmacopoeial reference standard (RS) for the bacterial suspension opacity of 10 international opacity units, the established pharmacopoeial RS for and two commercial batches of the live brucellosis vaccine (Brucella abortus 19 BA), and the established and candidate pharmacopoeial RSs for the live tularaemia vaccine (Francisella tularensis 15 NIIEG). These pharmacopoeial RSs were certified by the Scientific Centre for Expert Evaluation of Medicinal Products. Serological testing used Russian commercial diagnostic products, including dry diagnostic sera (polyvalent brucellosis and tularaemia sera for agglutination tests), a liquid erythrocytic diagnostic preparation of tularaemia immunoglobulin, and enzyme immunoassay (ELISA) diagnostic kits for detecting the causative agents for brucellosis and tularaemia. Statistical analysis involved using Microsoft Excel (P=0.95) for ELISA results and qualitative evaluation for the results of direct agglutination and indirect haemagglutination tests.RESULTS. All the tested batches demonstrated positive results. Live brucellosis vaccine batches showed positive results in the slide agglutination tests, while live tularaemia vaccine batches yielded positive results in the tube agglutination tests. All indirect haemagglutination tests showed haemagglutination in live tularaemia vaccine samples at the same concentration as positive control samples (6.25×10⁶ cells/mL). ELISA tests showed similar optical density values (D) for the two vaccines and positive control samples. Live tularaemia and brucellosis vaccines (undiluted, 1.0×10⁹ cells/mL) had D=2.133±0.273 and D=0.127±0.013, whereas the corresponding control samples had D=1.942±0.056 and D=0.123±0.007, respectively. The results reflected the presence of brucellosis or tularaemia microbes in the samples, confirming the identity of the vaccines.CONCLUSIONS. Serological immunoenzymatic, direct agglutination, and indirect haemagglu tination methods with Russian diagnostic products can be used to identify live brucellosis and tularaemia vaccines during quality assessment. The agglutination method with Russian diagnostic sera can be recommended as an alternative quality assessment method for the identification of live brucellosis and tularaemia vaccines, as this method offers time efficiency, simple visual evaluation of results, and low costs and relatively long shelf lives of diagnostic products. However, ELISA and indirect haemagglutination methods cannot be recommended for this purpose because of their labour-intensive and uneconomical nature. The results of this study may support the introduction of the agglutination method in the regulatory documents for live brucellosis and tularaemia vaccines (as an alternative method).

Abstract Background Accurate estimation of SARS-CoV-2 re-infection is crucial to understanding the connection between infection burden and adverse outcomes. However, relying solely on PCR testing results in underreporting. We present a novel approach that includes longitudinal serologic data, and compared it against testing alone among people experiencing homelessness. Methods We recruited 736 individuals experiencing homelessness in Toronto, Canada, between June and September 2021. Participants completed surveys and provided saliva and blood serology samples every three months over 12 months of follow-up. Re-infections were defined as: positive PCR or rapid antigen test (RAT) results > 90 days after initial infection; new serologic evidence of infection among individuals with previous infection who sero-reverted; or increases in anti-nucleocapsid in seropositive individuals whose levels had begun to decrease. Results Among 381 participants at risk, we detected 37 re-infections through PCR/RAT and 98 re-infections through longitudinal serology. The comprehensive method identified 37.4 re-infection events per 100 person-years, more than four-fold more than the rate detected through PCR/RAT alone (9.0 events/100 person-years). Almost all test-confirmed re-infections (85%) were also detectable by longitudinal serology. Conclusions Longitudinal serology significantly enhances the detection of SARS-CoV-2 re-infections. Our findings underscore the importance and value of combining data sources for effective research and public health surveillance.

Simple Summary: Sheep scab, caused by infestation with the ectoparasitic mite Psoroptes ovis, is endemic in Northern Ireland (NI). The disease continues to cause NI's sheep farming industry significant challenges, negatively impacting sheep and farmer welfare. The diagnosis of sheep scab has traditionally been achieved by taking skin scrape samples from suspected lesional areas on sheep suspected of being infested with sheep scab. These skin scrape samples are then examined under a microscope to confirm the presence of Psoroptes ovis mites, which provides a definitive diagnosis of the disease. However, while this method of diagnosis is highly specific for sheep scab, there can be a high level of variability in the sensitivity of the method, which can be as low as 18 percent. The objective of this study was to analyse the behavioural factors influencing the intention of sheep farmers to adopt sheep scab control measures in the form of blood testing. To achieve our objective, we analysed data from a sample of 126 sheep farmers using quantitative techniques. The results show that the promotion of a positive attitude towards blood testing for subclinical diagnoses of the disease would go a long way in controlling sheep scab in NI. Sheep scab, caused by infestation with the ectoparasitic mite Psoroptes ovis, is an endemic disease in the Northern Ireland (NI) sheep flock and constitutes significant economic and welfare burdens for the NI farming industry. Despite its endemic nature, historically, little research has been undertaken to support the control of the disease in NI. This study offers the first attempt to analyse the psychological and behavioural factors influencing farmers' intentions to implement effective sheep scab control measures in NI. To achieve our objective, quantitative data from a sample of 126 sheep farmers were statistically analysed using an extended theory of planned behaviour approach in an ordered logistic regression modelling framework. Our analyses showed that sheep scab remains an issue of concern in Northern Ireland. The attitudes of the farmers, as well as perceived behavioural control, emotional effect, membership of Business Development Groups (BDGs), and higher education qualifications, were found to be statistically significant factors influencing farmers' intentions to adopt sheep scab control measures. This study provides a solid foundation for how to promote behavioural changes among sheep farmers to improve their ability to implement effective disease control measures, helping to tackle this challenging disease in a more sustainable way in the future. [ABSTRACT FROM AUTHOR]

Background: Accurate estimation of SARS-CoV-2 re-infection is crucial to understanding the connection between infection burden and adverse outcomes. However, relying solely on PCR testing results in underreporting. We present a novel approach that includes longitudinal serologic data, and compared it against testing alone among people experiencing homelessness. Methods: We recruited 736 individuals experiencing homelessness in Toronto, Canada, between June and September 2021. Participants completed surveys and provided saliva and blood serology samples every three months over 12 months of follow-up. Re-infections were defined as: positive PCR or rapid antigen test (RAT) results > 90 days after initial infection; new serologic evidence of infection among individuals with previous infection who sero-reverted; or increases in anti-nucleocapsid in seropositive individuals whose levels had begun to decrease. Results: Among 381 participants at risk, we detected 37 re-infections through PCR/RAT and 98 re-infections through longitudinal serology. The comprehensive method identified 37.4 re-infection events per 100 person-years, more than four-fold more than the rate detected through PCR/RAT alone (9.0 events/100 person-years). Almost all test-confirmed re-infections (85%) were also detectable by longitudinal serology. Conclusions: Longitudinal serology significantly enhances the detection of SARS-CoV-2 re-infections. Our findings underscore the importance and value of combining data sources for effective research and public health surveillance. [ABSTRACT FROM AUTHOR]

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Blood transfusion remains an indispensable component of health care, contributing to saving millions of lives each year. Donating blood is an exceptionally special way to help another human being and save their life. Blood is an invaluable medicine that humans produce themselves, being the only source of this medicine. Blood transfusion is categorized as a form of transplantation, offering vital assistance to individuals in need while ensuring that it does not harm them in any way. Blood products must meet numerous national requirements to ensure their safety for use. Transfusion of incompatible blood or blood infected with bloodborne diseases can worsen the patient's condition, and in some cases, even lead to death. Ensuring a safe transfusion requires careful donor selection, comprehensive blood screening, and rigorous testing of blood products. Due to the emergence of new pathogens posing public health concerns, over time, mandatory testing of blood donors has included tests to detect these pathogens, aiming to reduce the risk of bloodbourne diseases. The detection and appropriate handling of reactive blood donations directly mitigate the risk of harm and the development of infections or diseases that the pathogen might induce in the recipient of the blood transfusion. Testing blood donors for HIV, hepatitis B and C, and Syphilis has become a foundation that persists to this day, significantly improving the safety of blood products. However, there was a challenge with the speed of infection detection, as many infected individuals could still be donors before the virus became detectable in the blood. The main goal was to produce higher quality and more reliable tests. After the successful implementation of serological testing for all voluntary blood donors worldwide, the safety of blood products has finally reached a high level. To provide an additional layer of blood safety, in the late 90s and early 2000s, the world gradually began to introduce molecular screening techniques for donors, known as Nucleic Acid Testing (NAT). The implementation of NAT testing has been a significant step in ensuring the safety of blood products. One of great advantages of NAT is its ability to detect and amplify very small amounts of viruses that are not detectable by serological test (18) In order to ensure the highest quality and safety of blood products, it is not sufficient to solely rely on laboratory tests and interpret their results. It is necessary to have a comprehensive strategy, standards, systems, and infrastructure prescribed by national health authorities and transfusion centers, and implemented into the laws and regulations of each individual country. Ongoing advancements in serological testing technologies contribute to improved sensitivity and specificity. The implementation of a comprehensive quality system in transfusion medicine and laboratory testing is of utmost importance, and continuous improvement should be the goal. It is crucial to continue monitoring all emerging threats to the safety of blood products and provide an adequate response. [ABSTRACT FROM AUTHOR]

Background: Although the risk of gastric cancer can be stratified according to Helicobacter pylori (H. pylori) IgG antibody titer and pepsinogen levels (ABC classification), a population-based gastric cancer screening system combining serological tests and endoscopy has not been introduced. This study aimed to compare the total testing cost per participant between the ABC classification method and the existing protocol. Methods: Using the minimization method with sex and age as allocation factors, 1206 participants were randomly assigned to the following two methods for a 5-year intervention: barium photofluorography as primary examination followed by detailed examination with upper gastrointestinal endoscopy (Ba-Endo) and risk-based upper gastrointestinal endoscopy by ABC classification (ABC-Endo). The primary endpoint was the total testing cost per participant over a 5-year period. The secondary endpoint was the expense required to detect one gastric cancer. Results: The total testing cost per participant was 39,711 yen in Ba-Endo (604 participants) and 45,227 yen in ABC-Endo (602 participants), with the latter being significantly higher (p < 0.001). During the intervention period, gastric cancer was found in 11 and eight participants in Ba–Endo and ABC-Endo, respectively. The expenses required to detect one gastric cancer were 2,240,931 yen in Ba-Endo and 3,486,662 yen in ABC-Endo. Conclusions: The testing cost per participant turned out to be higher in the ABC-Endo group than in the Ba-Endo group. This superiority trial, based on the hypothesis that the cost of testing is lower for ABC-Endo than for Ba-Endo, was rejected. [ABSTRACT FROM AUTHOR]

Background and Aims Coinfection of hepatitis delta virus (HDV) with hepatitis B virus (HBV) causes the most severe form of viral hepatitis, and the global prevalence of HDV infection is underestimated. Although serological testing of anti-HDV antibodies is widely used in the diagnosis of HDV, its diagnostic efficacy remains unclear. This study aimed to evaluate the diagnostic efficacy of HDV serological tests, the results of which may assist in the diagnosis of HDV. Methods Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. The PubMed, Web of Science and Cochrane Library databases were searched from the beginning to 31 May 2023. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. STATA SE was used for the meta-analysis of the sensitivity, specificity, positive likelihood ratio and negative likelihood ratio. Results Among a total of 1376 initially identified studies, only 12 articles met the final inclusion criteria. The pooled sensitivity and specificity were 1.00 (95% CI: 0.00–1.00) and 0.71 (95% CI: 0.50–0.78) for HDV total antibodies, 0.96 (95% CI: 0.83–0.99) and 0.98 (95% CI: 0.82–1.00) for anti-HDV IgM and 0.95 (95% CI: 0.86–0.98) and 0.96 (95% CI: 0.67–1.00) for anti-HDV IgG. The pooled sensitivity and specificity for HDV serological tests were 0.99 (95% CI: 0.96–1.00) and 0.90 (95% CI: 0.79–0.96). Conclusions This meta-analysis suggests that serological tests have high diagnostic performance in detecting antibodies against HDV, especially in HDV IgM and IgG. However, this conclusion is based on studies of a limited number and quality, and the development of new diagnostic tools with higher precision and reliability is still necessary. [ABSTRACT FROM AUTHOR]

Background and Objectives: A newborn presented with jaundice in Thailand. The cord red cells tested positive by direct antiglobulin test (DAT) for an unknown maternal red cell antibody. Initial blood group sequencing suggested that the infant carried a novel variant RHAG c.140T>C, responsible for a low‐prevalence antigen in the RHAG blood group system (ISBT 030). We report here on testing of samples from the infant's parents and older sibling to define a new antigen in the RHAG system. Materials and Methods: Massive parallel sequencing (MPS) using a custom‐designed panel was performed on all four family members. Extended serological testing was also performed to determine whether family members with the same variant as the infant showed reactivity with the antibody in the maternal plasma. Results: We identified a novel single nucleotide variant (SNV) (RHAG c.140T>C, p.[Phe47Ser]) in samples from three of the four family members tested (the infant, the older sibling and the father). The variant was not detected in the mother's sample. Maternal plasma showed positive agglutination with all family members tested; however, when tested with routine panel cells, no reactivity was observed. Conclusion: This case study showed that the presence of the novel variant (RHAG c.140T>C), encoding a p.(Phe47Ser) change in the RhAG glycoprotein, was the apparent cause of incompatibility between maternal plasma and that of red cells from the proband, father and older sibling of the proband. We propose this variant to be a new low‐prevalence antigen in the RHAG blood group system. [ABSTRACT FROM AUTHOR]

Background: Quantification of the SARS-CoV-2-specific immune response by serological immunoassays is critical for the management of the COVID-19 pandemic. In particular, neutralizing antibody titers to the viral spike (S) protein have been proposed as a correlate of protection (CoP). The WHO established the First International Standard (WHO IS) for anti-SARS-CoV-2 immunoglobulin (Ig) (NIBSC 20/136) to harmonize binding assays with the same antigen specificity by assigning the same unitage in binding antibody units (BAU)/ml. Method: In this study, we analyzed the S1-specific antibody response in a cohort of healthcare workers in Germany (n = 76) during a three-dose vaccination course over 8.5 months. Subjects received either heterologous or homologous prime-boost vaccination with ChAdOx1 nCoV-19 (AstraZeneca) and BNT162b2 (Pfizer-BioNTech) or three doses of BNT162b2. Antibodies were quantified using three anti-S1 binding assays (ELISA, ECLIA, and PETIA) harmonized to the WHO IS. Serum levels of neutralizing antibodies were determined using a surrogate virus neutralization test (sVNT). Binding assays were compared using Spearman's rank correlation and Passing-Bablok regression. Findings: All assays showed good correlation and similar antibody kinetics correlating with neutralizing potential. However, the assays show large proportional differences in BAU/ml. ECLIA and PETIA, which detect total antibodies against the receptor-binding domain (RBD) within the S1 subunit, interact similarly with the convalescent plasma-derived WHO IS but differently with vaccine serum, indicating a high sensitivity to the IgG/IgM/IgA ratio. Conclusion: All three binding assays allow monitoring of the antibody response in COVID-19-vaccinated individuals. However, the assay-specific differences hinder the definition of a common protective threshold in BAU/ml. Our results highlight the need for the thoughtful use of conversion factors and consideration of method-specific differences. To improve the management of future pandemics and harmonize total antibody assays, we should strive for reference material with a well-characterized Ig isotype composition. [ABSTRACT FROM AUTHOR]

Background: The WHO and CDC recommend that HCWs who are at risk of HBV infection should vaccinate as adults early in their career by receiving 3 doses of HB vaccine at a schedule of months 0,1,6 and perform post-vaccination serological testing 1–2 months after vaccination. This study assessed adherence to all three components of the HBV vaccination program. Methods: The study was a hospital-based analytical cross-sectional study involving 340 HCWs who were randomly selected. A pretested questionnaire was used to collect data which was analyzed using SPSS version 21. The proportion of HCWs adhering to the three components of the HBV vaccination protocol was computed. The multivariable analysis procedure identified the factors associated with overall adherence. Odds ratios were estimated with corresponding confidence intervals with the level of significance set at 0.05. Results: HBV vaccination coverage was 60.9 % and adherence to 3-doses, 0,1,6 vaccination schedules and post-vaccination serological testing were 46.8 %, 38 % and 13 % respectively. Overall adherence was intermediate at the population level with only 6.2 % of the study participants adhering to all three components of the HBV vaccination protocol. HCWs who had low-risk perception for HBV had the lowest odds of completely adhering to all three indicators recommended for HBV vaccination (aOR = 0.15; 95 %CI = 0.04–0.58). Also, male HCWs have lower odds of adhering to all three components of HBV vaccination compared to their female counterparts (aOR = 0.65; 95 %CI = 1.17–2.50). Conclusion: Adherence to the three components of HBV vaccination recommended for HCWs is low in this study. Failure to receive the recommended three-dose series of HBV vaccine at the recommended 0,1,6 schedule has implications for achieving seroprotection or development of antibodies against HBV. Failure to perform post-vaccination testing 1–2 months after HBV vaccination has implications for timely PEP management following occupational exposures. All three components of an ideal HBV vaccination program are important and should be used collectively to guide facility led HCW vaccination programs. Occupational health and safety programs, Infection prevention and control, as well as health promotion campaigns in health facilities, should promote adherence to all three components of HBV vaccination programs.

The aim of the reserch was to investigate the genotype of the pathogen in a patient with Lyme carditis and to analyze the course of the disease in the process of etiotropic treatment. The article describes a clinical case of infectious myocarditis associated with Lyme disease in a 49-year-old patient. The value of modern diagnostics technologies in diagnosis determination was described. The course of the disease and the results of treatment of the patient were analyzed. The severe rhythm and conduction disorders were revealed with the method of Holter monitoring: AV-block of the first degree, transient AV-block of the II degree (Mobitz 2) and III degree, polytopic extrasystoles. The morphological changes in the heart were diagnosed with ultrasonography and cardiac MRI in order to confirm the diagnosis and to monitor the patient's subsequent course. Total antibodies to antigens of the B. burgdorferi sensu lato complex in blood serum were determined by the ELISA method with test systems Euroimmun AG (Germany). At the second stage, the immunoblot method was applied using the EUROLINE Borrelia RN-AT test system. Due to timely diagnosis, including serological, prescribed etiotropic antibacterial treatment, the patient achieved a significant improvement in both clinical condition and positive serological and ECG dynamics with improved AV conduction. The most frequent ECG changes in Lyme carditis are conduction disorders with development of blockades of various stages. The application of the modern technologies in patients with myocarditis made it possible to determine the etiological factor of the disease with the establishment of genotypes, which caused Lyme carditis.

The impact of pre-existing common cold coronavirus (CCCoV) antibodies (Abs) on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune responses and pathogenesis remains poorly defined. We evaluated these associations in a cohort of hospitalized patients with COVID-19 and respiratory failure of varying severity. Patients with respiratory failure from other causes (non-COVID-19) were evaluated as controls. We demonstrated a positive correlation between levels of CCCoV and SARS-CoV-2 Abs using CCCoV and SARS-CoV-2 N and S protein peptide-specific ELISA. Consistent with the above, moderately increased levels of CCCoV-specific Abs in non-COVID-19 vs. COVID-19 patients suggest potential protective effects. Further, higher SARS-CoV-2 N protein-specific and CCCoV Ab levels were observed among surviving vs. non-surviving COVID-19 positive patients. However, the highest SARS-CoV-2 N and S protein-specific IgG and IgA Ab levels were noted in the patients with the most severe clinical disease. Finally, advanced age, cancer and immunosuppression were associated with significantly higher mortality and reduced SARS-CoV-2 and CCCoV Ab levels. Thus, our data highlight that sufficient SARS-CoV-2 N protein-specific Ab responses improve clinical outcomes in severely ill COVID-19 patients. We also confirmed that pre-existing CCCoV-specific Abs do not inhibit the SARS-CoV-2 Ab response and may further reduce the prevalence and/or severity of COVID-19.

The impact of pre-existing common cold coronavirus (CCCoV) antibodies (Abs) on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune responses and pathogenesis remains poorly defined. We evaluated these associations in a cohort of hospitalized patients with COVID-19 and respiratory failure of varying severity. Patients with respiratory failure from other causes (non-COVID-19) were evaluated as controls. We demonstrated a positive correlation between levels of CCCoV and SARS-CoV-2 Abs using CCCoV and SARS-CoV-2 N and S protein peptide-specific ELISA. Consistent with the above, moderately increased levels of CCCoV-specific Abs in non-COVID-19 vs. COVID-19 patients suggest potential protective effects. Further, higher SARS-CoV-2 N protein-specific and CCCoV Ab levels were observed among surviving vs. non-surviving COVID-19 positive patients. However, the highest SARS-CoV-2 N and S protein-specific IgG and IgA Ab levels were noted in the patients with the most severe clinical disease. Finally, advanced age, cancer and immunosuppression were associated with significantly higher mortality and reduced SARS-CoV-2 and CCCoV Ab levels. Thus, our data highlight that sufficient SARS-CoV-2 N protein-specific Ab responses improve clinical outcomes in severely ill COVID-19 patients. We also confirmed that pre-existing CCCoV-specific Abs do not inhibit the SARS-CoV-2 Ab response and may further reduce the prevalence and/or severity of COVID-19. [ABSTRACT FROM AUTHOR]

BackgroundQuantification of the SARS-CoV-2-specific immune response by serological immunoassays is critical for the management of the COVID-19 pandemic. In particular, neutralizing antibody titers to the viral spike (S) protein have been proposed as a correlate of protection (CoP). The WHO established the First International Standard (WHO IS) for anti-SARS-CoV-2 immunoglobulin (Ig) (NIBSC 20/136) to harmonize binding assays with the same antigen specificity by assigning the same unitage in binding antibody units (BAU)/ml.MethodIn this study, we analyzed the S1-specific antibody response in a cohort of healthcare workers in Germany (n = 76) during a three-dose vaccination course over 8.5 months. Subjects received either heterologous or homologous prime-boost vaccination with ChAdOx1 nCoV-19 (AstraZeneca) and BNT162b2 (Pfizer-BioNTech) or three doses of BNT162b2. Antibodies were quantified using three anti-S1 binding assays (ELISA, ECLIA, and PETIA) harmonized to the WHO IS. Serum levels of neutralizing antibodies were determined using a surrogate virus neutralization test (sVNT). Binding assays were compared using Spearman’s rank correlation and Passing–Bablok regression.FindingsAll assays showed good correlation and similar antibody kinetics correlating with neutralizing potential. However, the assays show large proportional differences in BAU/ml. ECLIA and PETIA, which detect total antibodies against the receptor- binding domain (RBD) within the S1 subunit, interact similarly with the convalescent plasma-derived WHO IS but differently with vaccine serum, indicating a high sensitivity to the IgG/IgM/IgA ratio.ConclusionAll three binding assays allow monitoring of the antibody response in COVID-19-vaccinated individuals. However, the assay-specific differences hinder the definition of a common protective threshold in BAU/ml. Our results highlight the need for the thoughtful use of conversion factors and consideration of method-specific differences. To improve the management of future pandemics and harmonize total antibody assays, we should strive for reference material with a well-characterized Ig isotype composition.

Background: The true burden of COVID‐19 in low‐ and middle‐income countries remains poorly characterized, especially in Africa. Even prior to the availability of SARS‐CoV‐2 vaccines, countries in Africa had lower numbers of reported COVID‐19 related hospitalizations and deaths than other regions globally. Methods: Ugandan blood donors were evaluated between October 2019 and April 2022 for IgG antibodies to SARS‐CoV‐2 nucleocapsid (N), spike (S), and five variants of the S protein using multiplexed electrochemiluminescence immunoassays (MesoScale Diagnostics, Rockville, MD). Seropositivity for N and S was assigned using manufacturer‐provided cutoffs and trends in seroprevalence were estimated by quarter. Statistically significant associations between N and S antibody seropositivity and donor characteristics in November–December 2021 were assessed by chi‐square tests. Results: A total of 5393 blood unit samples from donors were evaluated. N and S seropositivity increased throughout the pandemic to 82.6% in January–April 2022. Among seropositive individuals, N and S antibody levels increased ≥9‐fold over the study period. In November–December 2021, seropositivity to N and S antibody was higher among repeat donors (61.3%) compared with new donors (55.1%; p =.043) and among donors from Kampala (capital city of Uganda) compared with rural regions (p =.007). Seropositivity to S antibody was significantly lower among HIV‐seropositive individuals (58.8% vs. 84.9%; p =.009). Conclusions: Despite previously reported low numbers of COVID‐19 cases and related deaths in Uganda, high SARS‐CoV‐2 seroprevalence and increasing antibody levels among blood donors indicated that the country experienced high levels of infection over the course of the pandemic. [ABSTRACT FROM AUTHOR]

The aim of the reserch was to investigate the genotype of the pathogen in a patient with Lyme carditis and to analyze the course of the disease in the process of etiotropic treatment. The article describes a clinical case of infectious myocarditis associated with Lyme disease in a 49-year-old patient. The value of modern diagnostics technologies in diagnosis determination was described. The course of the disease and the results of treatment of the patient were analyzed. The severe rhythm and conduction disorders were revealed with the method of Holter monitoring: AV-block of the first degree, transient AV-block of the II degree (Mobitz 2) and III degree, polytopic extrasystoles. The morphological changes in the heart were diagnosed with ultrasonography and cardiac MRI in order to confirm the diagnosis and to monitor the patient's subsequent course. Total antibodies to antigens of the B. burgdorferi sensu lato complex in blood serum were determined by the ELISA method with test systems Euroimmun AG (Germany). At the second stage, the immunoblot method was applied using the EUROLINE Borrelia RN-AT test system. Due to timely diagnosis, including serological, prescribed etiotropic antibacterial treatment, the patient achieved a significant improvement in both clinical condition and positive serological and ECG dynamics with improved AV conduction. The most frequent ECG changes in Lyme carditis are conduction disorders with development of blockades of various stages. The application of the modern technologies in patients with myocarditis made it possible to determine the etiological factor of the disease with the establishment of genotypes, which caused Lyme carditis. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Incidence in first-time and repeat blood donors is an important measure of transfusion-transmitted HIV infection (TT-HIV) risk. This study assessed HIV incidence over time at four large blood centres in Brazil. MATERIALS AND METHODS: Donations were screened and confirmed using serological assays for HIV from 2007 to 2016, and additionally screened by nucleic acid testing from 2011 forward. Limiting antigen (LAg) avidity testing was conducted on HIV seroreactive samples from first-time donors to classify whether an infection was recently acquired. We calculated incidence in first-time donors using the mean duration of recent infection and in repeat donors using classical methods. Time and demographic trends were assessed using Poisson regression. RESULTS: Over the 10-year period, HIV incidence in first-time donors was highest in Recife (45·1/100 000 person-years (105 py)) followed by São Paulo (32·2/105 py) and then Belo Horizonte (23·3/105 py), and in repeat donors was highest in Recife (33·2/105 py), Belo Horizonte (27·5/105 py) and São Paulo (17·0/105 py). Results from Rio de Janeiro were available from 2013 to 2016 with incidence in first-time donors of 35·9/105 py and repeat donors from 2011 to 2016 of 29·2/105 py. Incidence varied by other donor demographics. When incidence was considered in 2-year intervals, no significant trend was evident. Overall residual risk of TT-HIV was 5·46 and 7·41 per million units of pRBC and FFP transfused, respectively. CONCLUSION: HIV incidence in both first-time and repeat donors varied by region in Brazil. Clear secular trends were not evident.

Sheep scab, caused by infestation with the ectoparasitic mite Psoroptes ovis, is an endemic disease in the Northern Ireland (NI) sheep flock and constitutes significant economic and welfare burdens for the NI farming industry. Despite its endemic nature, historically, little research has been undertaken to support the control of the disease in NI. This study offers the first attempt to analyse the psychological and behavioural factors influencing farmers’ intentions to implement effective sheep scab control measures in NI. To achieve our objective, quantitative data from a sample of 126 sheep farmers were statistically analysed using an extended theory of planned behaviour approach in an ordered logistic regression modelling framework. Our analyses showed that sheep scab remains an issue of concern in Northern Ireland. The attitudes of the farmers, as well as perceived behavioural control, emotional effect, membership of Business Development Groups (BDGs), and higher education qualifications, were found to be statistically significant factors influencing farmers’ intentions to adopt sheep scab control measures. This study provides a solid foundation for how to promote behavioural changes among sheep farmers to improve their ability to implement effective disease control measures, helping to tackle this challenging disease in a more sustainable way in the future.

Introduction: Hepatitis B Virus (HBV) infection is an important occupational hazard to Health Care Workers (HCWs) all over the world. International health organizations have strongly recommended the use of the HBV vaccine, especially among individuals at risk of HBV infection. A laboratory test aimed at measuring Anti-HBs concentration (titer) 1–2 months following a 3-dose vaccination schedule is the most reliable approach for diagnosing seroprotection against HBV. This study sought to assess post-vaccination serological testing, seroprotection against HBV, and associated factors among vaccinated HCWs in Ghana. Methods: A hospital-based analytical cross-sectional study involving 207 HCWs. Pretested questionnaires were used to collect data. 5mls of venous blood were collected from consenting HCWs under strict aseptic conditions and quantitatively analyzed for Anti-HBs using ELISA procedures. SPSS Version 23 was used to analyze data with the level of significance set at 0.05. Results: Median age; 33, IQR of 29–39. The post-vaccination serological testing rate was 21.3 %. HCWs with high-risk perception and working at the regional hospital had lower odds of adherence to post-vaccination serological testing (aOR = 0.2; 95 % CI = 0.1–0.7) and (aOR = 0.1; 95 % CI = 0.1–0.6) p

Background: Administration of anti‐CD38 antibodies is a state‐of‐the‐art therapy for patients diagnosed with multiple myeloma (MM). However, this treatment frequently leads to pan‐agglutination of red blood cells (RBCs) in patients' serological testing making accurate blood typing and timely transfusion of compatible blood a challenging effort. The antigen masking indirect antiglobulin test (AMIAT) is an approach to address this diagnostic challenge. Study Design and Methods: A new reagent, called DaraEx plus, uses anti‐CD38 Fab fragments to mitigate the anti‐CD38 antibody interference in serological assays by masking CD38 on the cell surface. Its performance is extensively examined with commercial sera as well as with patient samples, and compared to the current standard method using dithiothreitol (DTT), which denatures the CD38 antigens on test panel erythrocytes. Results: In the Bio‐Rad ID System, DaraEx plus effectively mitigated the interference caused by anti‐CD38 antibodies in 86% of patient samples tested while DTT was successful in only 68%. Moreover, there was no negative influence on DTT‐sensitive blood group systems such as KEL upon DaraEx plus treatment. The agglutination reactions of all tested anti‐CD38 antibodies (Daratumumab, Felzartamab, and Isatuximab) were inhibited by DaraEx plus. The treatment was successful only if DaraEx plus was added to the test cells before the sample. Some of the other gel card systems tested showed background reactions with DaraEx plus‐treated cells. Conclusion: DaraEx plus treatment is straightforward and quick to perform. In the Bio‐Rad ID System, it is superior to DTT treatment in the prevention of anti‐CD38 antibody interference. [ABSTRACT FROM AUTHOR]

Background and Objectives: A group AB D‐positive child presented 1 year after haematopoietic stem cell transplant (HSCT) from a group O D‐negative donor as group A D‐negative. Engraftment remained at 100% in white cell lineages. The reason for the unusual result was explored, and the scarcely reported phenomenon of adsorption of secreted antigen was considered. This study also investigated the prevalence of secreted antigen adsorbed onto donor‐derived group O red blood cells (RBCs) in children after HSCT and defined a process for laboratory management. Materials and Methods: Retrospective data analysis of HSCTs carried out over 19 months at Great Ormond Street Hospital was conducted to identify cases of adsorbed A antigen after HSCT. Investigation of RBC reactions with different clones of anti‐A and in vitro experiments was performed to recreate adsorption. Results: Nineteen A to O HSCTs were conducted over 19 months, of which six (31%) displayed weak A antigen on RBCs despite full myeloid engraftment. Negative reactions with anti‐A were obtained when run on an alternative clone. Laboratory protocols for the future management of these cases have been developed. Conclusion: Passive adsorption of secreted antigen is responsible for these results and is more widespread than previously reported, as a third of A to O HSCTs at our centre demonstrated this phenomenon. A process has been implemented into the laboratory to manage this cohort, ensuring component groups compatible with both donor and recipient are given, and the shared care centres are aware of these requirements. [ABSTRACT FROM AUTHOR]

Background and Aims Coinfection of hepatitis delta virus (HDV) with hepatitis B virus (HBV) causes the most severe form of viral hepatitis, and the global prevalence of HDV infection is underestimated. Although serological testing of anti-HDV antibodies is widely used in the diagnosis of HDV, its diagnostic efficacy remains unclear. This study aimed to evaluate the diagnostic efficacy of HDV serological tests, the results of which may assist in the diagnosis of HDV. Methods Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. The PubMed, Web of Science and Cochrane Library databases were searched from the beginning to 31 May 2023. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. STATA SE was used for the meta-analysis of the sensitivity, specificity, positive likelihood ratio and negative likelihood ratio. Results Among a total of 1376 initially identified studies, only 12 articles met the final inclusion criteria. The pooled sensitivity and specificity were 1.00 (95% CI: 0.00–1.00) and 0.71 (95% CI: 0.50–0.78) for HDV total antibodies, 0.96 (95% CI: 0.83–0.99) and 0.98 (95% CI: 0.82–1.00) for anti-HDV IgM and 0.95 (95% CI: 0.86–0.98) and 0.96 (95% CI: 0.67–1.00) for anti-HDV IgG. The pooled sensitivity and specificity for HDV serological tests were 0.99 (95% CI: 0.96–1.00) and 0.90 (95% CI: 0.79–0.96). Conclusions This meta-analysis suggests that serological tests have high diagnostic performance in detecting antibodies against HDV, especially in HDV IgM and IgG. However, this conclusion is based on studies of a limited number and quality, and the development of new diagnostic tools with higher precision and reliability is still necessary.

Background and objectivesDonated blood is not currently screened for human T-cell lymphotropic virus (HTLV) in South Africa. Several small studies have detected HTLV-1 in South Africa, but prevalence by geographic region or population group is unavailable.Materials and methodsWe performed a large seroprevalence study of South African blood donors during 3 months in 2013. All geographic regions except the Western Cape were included, and Black and Coloured (local term for mixed race) donors were oversampled. Identity-unlinked plasma samples were screened with the Abbott Prism HTLV-1/2 assay, and repeatedly reactive samples were tested by the Inno-LIA HTLV-1/2 Score confirmatory assay. Odds ratios were calculated with multivariable logistic regression.ResultsOf 46 752 donors tested, 133 (0·28%) were initially reactive, 111 (0·24%) repeatedly reactive and 57 (0·12%) confirmed positive for HTLV-1; none were HTLV-2 positive. Prevalence was 0·062% weighted to annual blood donations but highly concentrated in the Black population group (OR = 20·24 CI: 2·77-147·88); higher in females than males (OR = 1·81 CI: 1·06-3·08); and in donors aged >50 years compared to ages 16-19 (OR = 6·4 CI: 2·95-13·86). After controlling for age, sex and population group, there was no difference in prevalence between new and repeat blood donors or among geographic regions within South Africa.ConclusionsWe conclude that HTLV-1 infection is widespread among the Black population of South Africa and its epidemiology is similar to other endemic areas. Because South Africa is increasing its recruitment of Black blood donors, the implications for blood screening require further consideration.

Diagnosis is the precursor to the treatment of a disease, and as such, it is vital for diagnosis to be both accurate and fast. Handling large scale outbreaks and pandemics can be tied to the effectiveness of diagnosis. In the current pandemic of COVID-19, both serological tests and RT-PCR are being used to diagnose COVID-19. SARS-CoV-2 initially broke through in Wuhan, China in December 2019, and since then it has rapidly developed into a pandemic with roughly fourteen million cases and roughly one million fatalities as of July 2021. In this scenario, serological testing is fast, and RT-PCR is accurate; however, what we need to effectively control the pandemic is to have a test that embodies both speed, accuracy, and accessibility. In this review, we will delve into the current SARS-CoV-2 diagnostic tests: RT-PCR and serological assays. Due to the novelty of research in the field, we will also discuss the significance of variants and how they affect the tests based on the key mechanisms behind these detection assays. [ABSTRACT FROM AUTHOR]

Introduction: COVID 19 caused by SARS coronavirus two has halted life across the globe since its emergence in December 2019. Most of the infected persons are asymptomatic or have mild symptoms. Serosurvey is vital for the estimation of the burden of infection. In this context, our study objective is to estimate the Seroprevalence of SARS CoV 2 IgG among the first-year medical students after the first wave in February 2021.Method: A cross-sectional study was conducted among the first-year medical students of Veer Surendra Sai Institute of Medical Sciences And Research. All the students were enrolled, and their data & serum sample was collected. Serum samples were tested for the presence of Anti-Spike IgG. Data were analyzed by using appropriate statistical tests.Results: The Seroprevalence of anti-SARS CoV 2 IgG was estimated to be 38.8 %. Most (82 %) of the students used the mask per recommendation. Use of mask, BMI, Contact history with COVID 19 patient, attending social gathering & previous COVID 19 were associated with Seropositivity. Regular mask use, BMI, and Previous COVID 19 were significant predictors for Seropositivity. Conclusion: The Seroprevalence of SARS Cov 2 after the first wave of the pandemic is less than 40 %. It calls for the proper implementation of a vaccination program with strict vigilance and surveillance to stop subsequent waves.

Hepatitis B surface Antigen (HBsAg) and hepatitis C antibody (anti-HCV) assays have been performed in most laboratories using a variety of analytical methods with different reagents for Hepatitis B virus (HBV) and Hepatitis C virus (HCV) screening1-2. The purpose of this study was to develop an EQA program for dual HBsAg and anti-HCV serological testing to ensure the accuracy and reliability of serological assays. A serum panel of 12 samples containing three negative, three positives for each virus and three positives for both of HBsAg and anti-HCV. These panels were distributed to 102 laboratories in the South of Vietnam. They were required to report their results and any problems encountered on EQA panel. The results show that performance of HBsAg and anti-HCV tests is not only different in terms of method used but also in the types of biological products. Rapid tests (RTs) to detect HBsAg and anti-HCV were most commonly used to screen for HBV and HCV in laboratories. The coincidence rates of RTs for HBsAg and anti-HCV serological assays were 88.24% and 89.86% respectively, while electrochemiluminescence (ECLs) and chemiluminescent immunoassays (CLIAs), Enzyme-linked immunosorbent assay (ELISA) showed the best performance for both HBsAg and anti-HCV testing. The most challenging was failed to detect weak positive samples. In conclusion, the differences in test results within and between groups of HBsAg and anti-HCV assay methods indicated a need to improve test conditions at laboratories in Viet Nam.

Background: During the last two years, a variety of assays for the serological detection of antibodies to the new SARS-CoV-2 virus have been launched and used as part of standard care in many laboratories. The pace with which these tests have been introduced into routine care emphasizes the importance of quality measures for analytical methods, particularly with regard to the implications of results for clinical and epidemiologic decisions. Accuracy, reliability and comparability of analytical test results are thus essential, and here external quality assessment (EQA) is the most important quality assurance tool. It allows us to achieve harmonization of test methods as a prerequisite for a high standard of performance for laboratory and analytical techniques and their interpretation. Methods: This EQA scheme consisted of pre-characterized clinical biospecimens dedicated to the analysis of anti-SARS-CoV-2 IgG total antibodies and differentiation into spike protein-specific IgG antibodies against SARS-CoV-2 (anti-S-SARS-CoV-2) and nucleocapsid-specific IgG antibodies against SARS-CoV-2 (anti-N-SARS-CoV-2). Results: A total of 239 laboratories across Europe participated in this scheme, called CoVimm. In detail, 536 results for anti-SARS-CoV-2 IgG, 431 results for anti-S-SARS-CoV-2 IgG, and 200 results for anti-N-SARS-CoV-2 IgG were reported. Based on the pre-defined thresholds, the success rates for the determination of anti-S-SARS-CoV-2 IgG and anti-N-SARS-CoV-2 IgG were 96% and 90%, respectively. Interestingly, only 64% of the participating laboratories successfully passed the EQA scheme for the determination of total anti-SARS-CoV-2 IgG. Conclusions: This EQA revealed serious concerns regarding the reliability and appropriate use of anti-SARS-CoV-2 antibody assays in routine care. In addition to the wide heterogeneity of different assays used by participating laboratories, a lack of standardization and harmonization is also evident. This is of particular importance for reliable and clinically meaningful interpretation of test results. [ABSTRACT FROM AUTHOR]

Lateral flow immunoassay (LFIA) is widely employed as point-of-care tests (POCT) for the diagnosis of infectious diseases. The accuracy of LFIA largely depends on the quality of the immunoreagents used. Typical LFIAs to reveal the immune response to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) employ anti-human immunoglobulin (hIG) antibodies and recombinant viral antigens, which usually are unstable and poorly soluble. Broad selective bacterial proteins, such as Staphylococcal protein A (SpA) and Streptococcal protein G (SpG) can be considered alternatives to anti-hIG to increase versatility and sensitivity of serological LFIAs because of their high binding capacity, interspecies reactivity, and robustness. We developed two colorimetric LFA devices including SpA and SpG linked to gold nanoparticles (GNP) as detectors and explored the use of a specific, stable, and soluble immunodominant fraction of the nucleocapsid protein from SARS-CoV-2 as the capturing agent. The optimal amount of SpA-GNP and SpG-GNP conjugates and the protein-to-GNP ratios were defined through a full factorial experimental design to maximize the diagnostic sensitivity of the LFIAs. The new LFA devices were applied to analyze 105 human serum samples (69 positive and 36 negatives according to reference molecular diagnostic methods). The results showed higher sensitivity (89.9%, 95% CI 82.7–97.0) and selectivity (91.7%, 82.6–100) for the SpA-based compared to the SpG-based LFA. In addition, 18 serum samples from cats and dogs living with COVID-19 patients were analyzed and 14 showed detectable levels of anti-SARS-CoV-2 antibodies, thus illustrating the flexibility of the SpA- and SpG-based LFAs. [ABSTRACT FROM AUTHOR]

Objectives: Serological assays for the presence of anti-SARS-CoV-2 antibodies are crucially needed for research and monitoring of the SARS-CoV-2 pandemic. Antibodies are reliability detected in capillary blood, a minimally invasive and cost-effective alternative to venous blood testing. However, there is a limited knowledge on feasibility of capillary blood self-sampling. This study compared the feasibility of capillary blood self-testing in people aged less than 65 vs. people aged 65 or more. A secondary aim was to investigate the performance of the Hem-Col® (no additive) device compared to venous blood testing. Design and methods: Data were collected in a prospective study in Switzerland (n = 106). Capillary blood was collected using the Hem-Col® (no additive) device. Feasibility was assessed using 1) collecting the recommended amount of capillary blood and 2) achieving all steps of capillary blood collection. A sample of 5 ml of venous blood was also collected. Results: For the primary objective, 86.2%/62.1% of patients aged less than 65 collected the recommended amount of capillary blood/achieved all steps vs. 62.5%/39.6% of patients aged 65 or more (p = .006/p = .022). For the secondary objective, the correlation between capillary and venous blood was r = 0.992 and kappa = 1. Conclusions: Capillary blood self-testing appeared as a feasible and reliable alternative to venous blood testing. Such alternative would improve access to serological testing and spare health care resources. However, the difference between age groups should be considered when using self-sampling devices. Help should be developed for older people, such as phone counseling or encouraging asking younger family members for help.

Objectives: This study aimed to estimate the serological prevalence of coeliac disease in patients with iron deficiency anaemia (IDA) of unknown cause at a primary healthcare facility in Oman. Methods: This prospective case-finding study was conducted at the primary care clinics in Sultan Qaboos University Hospital, Muscat, Oman from September 2018 to June 2020. Patients aged 18 to 55 years, with a haemoglobin (Hb) level <11.5 g/dL for males and <11.0 g/dL for females and a ferritin level <30 ng/mL for males and <13 ng/mL for females, were included in the study. Blood samples were obtained for initial serological screening using serum immunoglobulin (Ig)A level; those samples with normal levels of IgA, IgA anti-tissue transglutaminase antibody (tTG) and IgA anti-deamidated gliadin peptide (DGP) were determined. Positive IgA-tTG test was confirmed using IgA-endomysial antibodies. Patients with low IgA levels were tested using IgG-tTG and IgG-DGP. Results: A total of 104 patients participated in this study. Eight patients (7.7%) were found to have a positive serological screening result for coeliac disease; of these patients, three (37.5%) had a positive IgA-tTG result. Two of those three (66.7%) had a positive IgA-endomysial antibody. The IgA-DGP result was positive in seven (6.7%) of the 104 patients. Out of those seven patients, two also had a positive IgA tTG. Conclusion: Coeliac disease is not a rare disorder. There is a need to increase awareness among healthcare professionals about coeliac disease and its non-classical manifestations such as IDA. [ABSTRACT FROM AUTHOR]

Background: Throughout the coronavirus disease 2019 (Covid-19) pandemic numerous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays have been approved through Emergency Use Authorization and require further evaluation of sensitivity and specificity in clinical laboratory settings prior to implementation. Methods: We included 1733 samples from 375 PCR-confirmed SARS-CoV-2–positive individuals of the North Zealand Covid-19 Cohort in an 8-month period. We investigated diagnostic sensitivity and specificity against consensus and PCR and interassay agreement over time for 5 SARS-CoV-2 immunoassays [Roche-nucleocapsid (NC)-total, Roche-receptor binding domain (RBD)-total, Siemens-RBD-IgG, Siemens-RBD-total, Thermo Fisher Scientific (TFS)-RBD-IgG] commercially available on automated platforms and 2 ELISA assays (TFS-RBD-total, Wantai-RBD-total). Results: Early interassay discrepancy in up to 49% of samples decreased steadily during the first 18 days. By day 18, all assays had reached a plateau between 82.3% and 90.5% seropositivity compared to PCR. Assays ranked by closest agreement with the consensus model beyond day 18 (sensitivity/specificity against consensus) were as follows: Roche-RBD-total, 99.8%/100.0%; Wantai-RBD-total, 99.8%/99.7%; Roche-NC-total, 97.8%/100.0%; Siemens-RBD-total, 98.0%/98.7%; TFS-RBD-total, 96.9%/99.7%; TFS-RBD-IgG, 91.5%/100.0%; and Siemens-RBD-IgG, 94.6%/89.9%. We found that 7.8% of PCR-positive patients remained seronegative in all assays throughout the study. Conclusions: All included assays had sensitivities against consensus >90% past day 18. For the current recommended use of antibody assays to detect former, undocumented Covid-19, our data suggest the use of total antibody assays rather than IgG-specific assays due to higher long-term sensitivity. Finally, a nonresponding subpopulation of 7.8% in our cohort with persistent seronegative results raises concern of a possible substantial number of people with continued low protection following natural SARS-CoV-2 infection. [ABSTRACT FROM AUTHOR]

Background: Immunocompromised people (ICP) and elderly individuals (older than 80 years) are at increased risk for severe coronavirus infections. To protect against serious infection with SARS-CoV-2, ICP are taking precautions that may include a reduction of social contacts and participation in activities which they normally enjoy. Furthermore, for these people, there is an uncertainty regarding the effectiveness of the vaccination. The COVID-19 Contact (CoCo) Immune study strives to characterize the immune response to COVID-19 vaccination in immunocompromised, elderly people, and patients with hematological or oncological diseases. The study uses blood-based screenings to monitor the humoral and cellular immune response in these groups after vaccination. Questionnaires and qualitative interviews are used to describe the level of social participation.Methods: The CoCo Immune Study is a mixed methods prospective, longitudinal, observational study at two large university hospitals in Northern Germany. Starting in March 2021, it monitors anti-SARS-CoV-2 immune responses and collects information on social participation in more than 600 participants, at least 18 years old. Inclusion criteria and subcohorts: Participants with (1) regularly intake of immunosuppressive medication (ICP-cohort) or (2) age ≥ 80 years (80 + -cohort). Additionally, patients with current or former (3) myeloid, (4) lymphatic disease or (5) solid tumor under checkpoint inhibition (3-5: HO-cohort).Exclusion Criteria: (1) refusal to give informed consent, (2) contraindication to blood testing, (3) inability to declare consent. Participants complete a questionnaire at four different time points: prior to full vaccination, and 1, 6 and 12 months after completed vaccination. In addition, participants draw blood samples themselves or through a local health care provider and send them with their questionnaires per post at the respective time points after vaccination. Patients of the HO cohort dispense additional blood samples at week 3 to 12 and at month 6 to 9 after 2nd vaccination to gain additional knowledge in B and T cell responses. Selected participants are invited to qualitative interviews about social participation.Discussion: This observational study is designed to gain insight into the immune response of people with weakened immune systems and to find out how social participation is affected after COVID-19 vaccination.Trial Registration: This study was registered with German Clinical Trial Registry (registration number: DRKS00023972) on 30th December 2020. [ABSTRACT FROM AUTHOR]

Risk factors for disease progression and severity of SARS-CoV-2 infections require an understanding of acute and long-term virological and immunological dynamics. Fifty-one RT-PCR positive COVID-19 outpatients were recruited between May and December 2020 in Munich, Germany, and followed up at multiple defined timepoints for up to one year. RT-PCR and viral culture were performed and seroresponses measured. Participants were classified applying the WHO clinical progression scale. Short symptom to test time (median 5.0 days; p = 0.0016) and high viral loads (VL; median maximum VL: 3∙108 copies/mL; p = 0.0015) were indicative for viral culture positivity. Participants with WHO grade 3 at baseline had significantly higher VLs compared to those with WHO 1 and 2 (p = 0.01). VLs dropped fast within 1 week of symptom onset. Maximum VLs were positively correlated with the magnitude of Ro-N-Ig seroresponse (p = 0.022). Our results describe the dynamics of VLs and antibodies to SARS-CoV-2 in mild to moderate cases that can support public health measures during the ongoing global pandemic. • SARS-CoV-2 viral loads drop fast within one week of symptom onset. • Positive viral culture results have high viral loads and low symptom to test time. • Maximum viral loads positively correlate with the magnitude of Ro-N-Ig assay. • Maximum viral loads significantly differ between WHO groups. [ABSTRACT FROM AUTHOR]

Background: Countries use national policies to screen and diagnose people infected with the hepatitis C virus to prevent transmission and eliminate the disease. In May 2016, the World Health Organization set a target of 90% diagnosis and elimination of the disease by 2030. The aim of this study was to evaluate the screening and diagnostic algorithm of hepatitis C by serological methods. Methods: The blood samples of people referring to blood transfusion centers in Kerman province in southeastern Iran from January 2014 to January 2020 were examined with the defined algorithm for the presence of antibodies against hepatitis C virus by ELISA and confirmation test (RIBA). Results: Based on the algorithm used, little/no correlations were found between the effect of age on OD in ELISA and RIBA test results, respectively (r = 0.07, p = 0.03) and (r = 0.19, p = 0.001). The correlation between the amount of OD in the ELISA test and the results of RIBA test was (r = 0.24, p = 0.01) and no significant correlation was observed between OD in ELISA and the indeterminate immunoblot test results (r = -0.04 and p = 0.2). Conclusions: The results of this study show, in low-risk populations, all samples that have reactive ELISA results should be confirmed without considering the amount of ELISA OD and the signal-to-cut-off (S/Co) ratios. The existing algorithm should be modified as soon as possible and newer technologies should be used to perform the test. [ABSTRACT FROM AUTHOR]

The landscape of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic testing is rapidly evolving. While serology testing has limited diagnostic capacity for acute infection, its role in providing population-based information on positivity rates and informing evidence-based decision making for public health recommendations is increasing. With the global availability of vaccines, there is increasing pressure on clinical laboratories to provide antibody screening and result interpretation for vaccinated and non-vaccinated individuals. Here we present the most up-to-date data on SARS-CoV-2 antibody timelines, including the longevity of antibodies, and the production and detection of neutralizing antibodies. Additionally, we provide practical guidance for clinical microbiology laboratories to both verify commercial serology assays and choose appropriate testing algorithms for their local populations.

Abstract Background Amoebiasis caused by the protozoan species Entamoeba histolytica rarely develops into fulminant amoebic colitis (FAC), but when it does, it shows an aggressive clinical course including colonic perforation, necrotizing colitis, and high mortality. Surgical treatment for FAC patients should be carried out urgently. However, even after surgery, the mortality rate can be 40–50%. Although FAC is one of the most unfavorable surgical diseases with a poor prognosis, there are a few reports on the perioperative diagnosis and management of FAC based on autopsy findings. We herein report the surgical case of a 64-year-old man who developed multiple colon necrosis and perforation due to FAC. A detailed autopsy revealed FAC as the cause of death. Additionally, we reviewed the existing literature on FAC patients who underwent surgery and followed their perioperative diagnosis and management. Case presentation A 64-year-old man presented with anorexia, diarrhea, and altered consciousness on arrival to our hospital. Computed tomography revealed a large mass in the upper right lobe of his lung, and the patient was admitted for close investigation. Bloody diarrhea, lower abdominal pain, and hypotension were observed soon after admission. Urgent abdominal contrast-enhanced computed tomography scan revealed extensive intestinal ischemia, intestinal pneumatosis, and free intra-abdominal gas. The preoperative diagnosis was bowel necrosis and perforation with intussusception of the small intestinal tumor. Emergency subtotal colectomy and enterectomy were performed soon after the contrast-enhanced computed tomography. He was taken to an intensive care unit after surgery. However, he could not recover from sepsis and died with disseminated intravascular coagulation and multiple organ failure on the 10th-day post-surgery. A histopathological examination of the resected colon showed transmural necrosis and massive amoebae invasion. He was diagnosed with FAC. An autopsy revealed that he had developed pulmonary large cell carcinoma with small intestinal metastasis. The death was caused by intestinal ischemia, necrosis and the perforation of the residual bowel caused by amoebae invasion. Conclusions Since FAC is a lethal disease with a high mortality rate and antibiotic therapies except metronidazole are ineffective, preoperative serological testing and perioperative metronidazole therapy in FAC patients can dramatically improve their survival rates.

Pediatric optic neuritis (PON) is one of the commonest causes of acute vision loss in children. Although it might often be postinfectious or postvaccination, recent understanding and available evidence suggest that it can be the first manifestation of a neuro-inflammatory syndrome such as multiple sclerosis, neuromyelitis optica spectrum disorder, acute disseminated encephalomyelitis or myelin oligodendrocyte glycoprotein associated optic neuritis. Therefore, neuroimaging, serological testing, cerebrospinal fluid analysis, testing for various systemic autoimmune conditions become a part of the workup. However, this can be exhaustive and expensive, especially in countries with limited access to health insurance. Many recent studies suggest that neuroimaging and few clinical features can provide clues to the underlying etiology. However, serological tests can provide a confirmatory evidence. Therefore, in this mini-review, we propose a balanced approach to the evaluation of PON, based on the available literature emanating in the last decade.

Background: The considerable epidemiological and economic implications of paratuberculosis, caused by Mycobacterium avium subspecies paratuberculosis (MAP), have placed importance on control efforts aimed at preventing MAP transmission. In this context, Italy issued national guidelines for the control and status certification of MAP in dairy cattle in 2013. Methods: We assessed the long‐term outcomes of the Italian MAP control programme for 14 dairy farms located in northern Italy by retrospectively reviewing the results of yearly serological tests, presence of clinical cases, MAP faecal shedding in serologically positive animals, farm management and health ranking as indicators of herd health between 2014 and 2021. Results: A significantly higher number of serologically positive animals were observed between 2014 and 2016 than between 2017 and 2021, as well as an improving trend in the paratuberculosis health ranking for nine of the 14 farms. No clinical cases were reported. MAP shedding was detected in 9.4% of serologically positive animals. Discarding colostrum and prioritised culling of seropositive animals assisted by adoption of standardised serological testing were presumed to have a key role in MAP control, despite the reluctance of some farmers to address hygienic issues and improve the separation of calves from adult animals. Limitations: The small number of farms included in this study and the fact that these were not randomly selected may limit the generalisability of the findings. Conclusions: The Italian paratuberculosis control plan has provided measures to limit the uncontrolled spread of MAP infection within and between herds by promoting animal trading between farms certified as negative or low risk. [ABSTRACT FROM AUTHOR]

Background Confidence in natural immunity after infection with severe acute respiratory syndrome coronavirus 2 is one reason for vaccine hesitancy. Methods We measured antibody-mediated neutralization of spike protein-ACE2 receptor binding in a large community-based sample of seropositive individuals who differed in severity of infection (N = 790). Results A total of 39.8% of infections were asymptomatic, 46.5% were symptomatic with no clinical care, 13.8% were symptomatic with clinical care, and 3.7% required hospitalization. Moderate/high neutralizing activity was present after 41.3% of clinically managed infections, in comparison with 7.9% of symptomatic and 1.9% of asymptomatic infections. Conclusions Prior coronavirus disease 2019 infection does not guarantee a high level of antibody-mediated protection against reinfection in the general population. [ABSTRACT FROM AUTHOR]

Background and Objectives: Prediction of haemolytic disease of the foetus and newborn (HDFN) caused by maternal anti‐A/‐B enables timely therapy, thereby preventing the development of kernicterus spectrum disorder. However, previous efforts to establish accurate prediction methods have been only modestly successful. Materials and Methods: In a case–control study, we examined 76 samples from mothers and 76 samples from their newborns; 38 with and 38 without haemolysis. The IgG subclass profile of maternal anti‐A and anti‐B was determined by flow cytometry. Samples from newborns were genetically analysed for the A2 subgroup, secretor and FcγRIIa receptor alleles. Results: Surprisingly, we found a correlation between the newborn secretor allele and haemolysis (p = 0.034). No correlation was found for FcγRIIa alleles. The A2 subgroup was found only in newborns without haemolysis. Unexpectedly, different reaction patterns were found for maternal anti‐A and anti‐B; consequently, the results were treated separately. For the prediction of haemolysis in A‐newborns, the maternal IgG1 subclass determination resulted in an accuracy of 83% at birth. For B‐newborns, an accuracy of 91% was achieved by the maternal IgG2 subclass determination. Conclusion: We improved the prediction of ABO‐HDFN by characterizing maternal anti‐A and anti‐B by flow cytometry and we presented genetic traits in newborns with correlation to haemolysis. We propose a new understanding of A‐ and B‐substances as immunogens that enhance the maternal immune response and protect the newborn, and we suggest that the development of ABO‐HDFN is different when caused by maternal anti‐A compared to maternal anti‐B. [ABSTRACT FROM AUTHOR]

Implementing fully automated analyzers has become a crucial safety step in blood donation centers. The Elecsys® assays were evaluated on the cobas e 801 module (Roche Diagnostics) for routine first-time blood donor screening. Five Elecsys infectious disease assays were tested on the cobas e 801 module at Etablissement Français du Sang, Montpellier, France (March–April 2018). The performance of Elecsys HIV Duo, Anti-HCV II, HBsAg II, Anti-HBc II, and Syphilis assays was compared with PRISM HIV O Plus, HCV, HBsAg, HBcore, and newbio pk TPHA assays (specificity analyses)/ARCHITECT Syphilis TP (sensitivity analyses), respectively. Specificity was determined in residual fresh serum samples from unselected first-time blood donors (n ≥ 5195 per parameter). Elecsys assay sensitivity was tested using 30 preselected, positively characterized samples per assay and compared with archived routine testing data for comparator assays. Across all parameters, specificities for repeatedly reactive samples ranged from 99.81–100.00% for Elecsys assays and 99.71–99.98% for comparator assays. Sensitivities of Elecsys and comparator assays were the same for hepatitis C (85.19%), hepatitis B surface antigen (70.00%), hepatitis B core antigen antibodies (100.00%), and syphilis (100.00%). The sensitivity of the Elecsys HIV Duo assay was higher than the comparator assay (83.33% vs. 76.67%), but the difference was not statistically significant. Elecsys infectious disease assays on the cobas e 801 module demonstrated high specificity and sensitivity for screening first-time blood donor samples, and were comparable with other commercially available assays. The Elecsys assays are reliable tests for screening blood donations. [ABSTRACT FROM AUTHOR]

Introduction: Data have suggested that SARS-CoV-2 infection causes an antibody response at least as strong as one BNT162b2 vaccine dose. Nevertheless, some aspects require further investigation to better understand the immunogenicity of one vaccine dose among infected individuals. Thus, we evaluated how previous SARS-CoV-2 infection may influence the humoral immunity after a single Pfizer BNT162b mRNA vaccine dose in a sample of healthcare workers (HCWs). Methods: As part of the routine surveillance activity conducted among HCWs of the Policlinico Riuniti Foggia Hospital (Apulia region, Italy), we conducted a retrospective serosurvey in the period January–March 2021. We compared specific antibody titres (anti-spike IgGs measured by enzyme-linked immunoassay, ELISA) after SARS-CoV-2 infection and after the first dose of the BNT162b2 vaccine, analysing the impact of sex, age, time since infection, and presence of symptoms on the humoral response. Results: We included in the study 58 HCWs (mean age 44.1 years, 48.2% male) with anti-spike IgG titres available before and after the first BNT162b2 vaccine dose. Among these, we observed higher titres in previously infected cases (N = 21) than in COVID-19-naïve subjects (N = 37) (medians 1510 vs. 0.68; p < 0.001). A statistically significant difference in anti-spike IgG titres was also observed among previously infected HCWs before vaccine dose in comparison with post-dose infection-naïve HCWs (medians 18.37 vs. 0.68, p < 0.001). Among infected individuals, no differences by sex, age, or time since infection were reported (p > 0.05). Post-dose titres of symptomatic and asymptomatic infected HCWs slightly differed (medians = 1900 vs. 1090; p = 0.048). Conclusion: Our data support the viable hypothesis of a single-dose vaccine regimen in individuals with a history of COVID-19, but no conclusion on duration of protection in this group can be drawn from our study. [ABSTRACT FROM AUTHOR]

Determining the presence of antibodies to the SARS-CoV-2 antigens is the best way to identify infected people, regardless of the development of symptoms of COVID-19. The nucleoprotein (NP) of the SARS-CoV-2 is an immunodominant antigen of the virus; anti-NP antibodies are detected in persons previously infected with the virus with the highest titers. Many test systems for detecting antibodies to SARS-CoV-2 contain NP or its fragments as antigen. The sensitivity and specificity of such test systems differ significantly, which can be explained by variations in the antigenic properties of NP caused by differences in the methods of its cultivation, isolation and purification. We investigated this effect for the Escherichia coli-derived SARS-CoV-2 NP, obtained from the cytoplasm in the soluble form. We hypothesized that co-purified nucleic acids that form a strong complex with NP might negatively affect NP's antigenic properties. Therefore, we have established the NP purification method, which completely eliminates the RNA in the NP preparation. Two stages of RNA removal were used: treatment of the crude lysate of E. coli with RNase A and subsequent selective RNA elution with 2MNaCl solution. The resulting NP withoutRNA has a significantly better signal-to-noise ratio when used as an ELISA antigen and tested with a control panel of serum samples with antibodies to SARS-CoV-2; therefore, it is preferable for in vitro diagnostic use. The same increase of the signal-to-noise ratio was detected for the free N-terminal domain of the NP. Complete removal of RNA complexed with NP during purification will significantly improve its antigenic properties, and the absence of RNA in NP preparations should be controlled during the production of this antigen. [ABSTRACT FROM AUTHOR]

Determining the presence of antibodies to the SARS-CoV-2 antigens is the best way to identify infected people, regardless of the development of symptoms of COVID-19. The nucleoprotein (NP) of the SARS-CoV-2 is an immunodominant antigen of the virus; anti-NP antibodies are detected in persons previously infected with the virus with the highest titers. Many test systems for detecting antibodies to SARS-CoV-2 contain NP or its fragments as antigen. The sensitivity and specificity of such test systems differ significantly, which can be explained by variations in the antigenic properties of NP caused by differences in the methods of its cultivation, isolation and purification. We investigated this effect for the Escherichia coli-derived SARS-CoV-2 NP, obtained from the cytoplasm in the soluble form. We hypothesized that co-purified nucleic acids that form a strong complex with NP might negatively affect NP’s antigenic properties. Therefore, we have established the NP purification method, which completely eliminates the RNA in the NP preparation. Two stages of RNA removal were used: treatment of the crude lysate of E. coli with RNase A and subsequent selective RNA elution with 2 M NaCl solution. The resulting NP without RNA has a significantly better signal-to-noise ratio when used as an ELISA antigen and tested with a control panel of serum samples with antibodies to SARS-CoV-2; therefore, it is preferable for in vitro diagnostic use. The same increase of the signal-to-noise ratio was detected for the free N-terminal domain of the NP. Complete removal of RNA complexed with NP during purification will significantly improve its antigenic properties, and the absence of RNA in NP preparations should be controlled during the production of this antigen.