IgG Enzyme-linked Immunosorbent Assay Research Articles

An indirect ELISA for detecting anti-SARS-CoV-2 antibodies in human sera using a baculovirus-expressed recombinant nucleocapsid antigen

This study focuses on the development and initial assessment of an indirect IgG enzyme-linked immunosorbent assay (ELISA) specifically designed to detect of anti-SARS-CoV-2 antibodies. The unique aspect of this ELISA method lies in its utilization of a recombinant nucleocapsid (N) antigen, produced through baculovirus expression in insect cells. Our analysis involved 292 RT-qPCR confirmed positive serum samples and 54 pre-pandemic healthy controls. The process encompassed cloning, expression, and purification of the SARS-CoV-2 N gene in insect cells, with the resulted purified protein employed in our ELISA tests. Statistical analysis yielded an Area Under the Curve of 0.979, and the optimized cut-off exhibited 92 % sensitivity and 94 % specificity. These results highlight the ELISA's potential for robust and reliable serological detection of SARS-CoV-2 antibodies. Further assessments, including a larger panel size, reproducibility tests, and application in diverse populations, could enhance its utility as a valuable biotechnological solution for diseases surveillance.

Seroprevalence of the novel swine acute diarrhea syndrome coronavirus in China assessed by enzyme-linked immunosorbent assay.

The endemic outbreak of SADS-CoV has resulted in economic losses and potentially threatened the safety of China's pig industry. The molecular epidemiology of SADS-CoV in pig herds has been investigated in many provinces in China. However, there are no data over a long-time span, and there is a lack of extensive serological surveys to assess the prevalence of SADS-CoV in Chinese swine herds since the discovery of SADS-CoV. In this study, an indirect anti-SADS-CoV IgG enzyme-linked immunosorbent assay (ELISA) based on the SADS-CoV S1 protein was established to investigate the seroprevalence of SADS-CoV in Chinese swine herds. Cross-reactivity assays, indirect immunofluorescence, and western blotting assays showed that the developed ELISA had excellent SADS-CoV specificity. In total, 12,978 pig serum samples from 29 provinces/municipalities/autonomous regions in China were tested from 2022 to 2023. The results showed that the general seroprevalence of SADS-CoV in China was 59.97%, with seroprevalence ranging from 16.7% to 77.12% in different provinces and from 42.61% to 68.45% in different months. SADS-CoV is widely prevalent in China, and its seroprevalence was higher in Northeast China, North China, and Central China than in other regions. Among the four seasons, the prevalence of SADS-CoV was the highest in spring and the lowest in autumn. The results of this study provide the general seroprevalence profile of SADS-CoV in China, facilitating the understanding of the prevalence of SADS-CoV in pigs. More importantly, this study is beneficial in formulating preventive and control measures for SADS-CoV and may provide directions for vaccine development.

Comparison of an Enzyme Linked-Immunosorbent Assay and a Chemiluminescent Immunoassay with an Immunofluorescence Assay for Detection of Phase II IgM and IgG Antibodies to Coxiella burnetii.

In this study, we have compared the detection of IgM and IgG against C. burnetii phase II of an enzyme-linked immunosorbent assay (ELISA) (Euroimmun) and a chemiluminescent immunoassay (CLIA) (VIRCLIA, Vircell). In addition, an indirect immunofluorescence assay (IFA) was used as a reference test. One hundred forty-eight sera were used for IgG evaluation, and eighty-eight for IgM. The sensitivity of ELISA and CLIA in detecting phase II IgM was excellent. On the other hand, the CLIA IgM showed better specificity than the ELISA IgM. As for phase II IgG, the specificity of ELISA and CLIA was similar, while the ELISA technique showed a higher sensitivity. In conclusion, the best system to detect phase II IgM antibodies against C. burnetii is the CLIA from Vircell, which is characterized by high sensitivity and specificity. For the detection of phase II IgG, the Euroimmun ELISA and Vircell CLIA assays are suitable for the determination of this marker in the laboratory, although the IgG ELISA has greater sensitivity.

Seroepidemiology of Toxoplasma gondii in diabetic patients type 2 by enzyme-linked immunosorbent assay method in Zabol City, 2017-2018.

Type 2 diabetes mellitus (T2DM) is prone to opportunistic infections, including toxoplasmosis, due to an immunodeficiency system. This study aimed to evaluate the serum of people with T2DM to determine the titer of anti-toxoplasma antibodies in patients and compare it with the control group. 720 blood samples have been carried out between October and the end of January 2017 in Sistan, and Baluchestan provinces in southeastern Iran, of these, 360 samples were related to healthy individuals (control), and 360 samples were related to T2DM individuals. The immunoglobulin (Ig) M and IgG enzyme-linked immunosorbent assay methods have been used to detect toxoplasmosis. The data were analyzed using SPSS-19, Chi-square, and Fisher's exact test to compare statistical parameters. In this cross-sectional study, out of 360 samples of T2DM by ELISA method, 60% samples in diabetic patients and 48.1% in control group were IgG positive (P < 0.05). Nearly 2.5% samples in diabetic patients and 0.3% in control group were IgM positive (P < 0.05). Anti-toxoplasma antibodies including IgG and IgM were higher in diabetic patient in comparison to control group.

Evaluation of Three Cytomegalovirus IgG Lateral Flow Assays for Rapid Determination of CMV Serostatus.

Cytomegalovirus (CMV) serostatus is a major determinant of CMV infection, disease risk, and transplant outcomes. Current clinical serology assays are limited by relatively slow turnaround time, design for batched testing, need for trained personnel, and/or specialized equipment. Rapid diagnostic assays in development have a role in emerging settings, such as critically ill patients, but have not been systematically evaluated. We assessed the performance of 3 rapid lateral flow assays (LFAs) for the detection of CMV immunoglobulin (Ig)G antibodies compared with a reference commercially available CMV IgG enzyme-linked immunosorbent assay in residual serum samples from 200 consecutive adults who underwent clinical CMV serology testing. Samples with discrepant results between the LFA and reference assay were tested by a second reference assay. A subset of serum samples was assessed for interoperator variability. Operating characteristics of the QooLabs LFA were separately assessed in plasma samples. The sensitivity and specificity of the individual LFA assays using serum varied significantly: 86%/83%, 99/93%, and 57/97%, for Healgen, QNow automated reader, and nanoComposix, respectively, compared with the reference assay. Results for the QNow assay were comparable between automated and manual reads. Among a subset of 10 serum samples assessed by 5 individual operators, 44 of 50 (88%) results were concordant. Among 50 plasma samples assessed by the QooLabs LFA, the sensitivity and specificity were 72% and 96%. The ease of performance, rapid turnaround time, and good operating characteristics provide the rationale for further evaluation of the Qoolabs QNow LFA in specialized settings where rapid assessment of CMV serostatus would be advantageous.

Seroprevalence of Infection by Borrelia Species Responsible for Lyme Disease in the French Alps: Analysis of 27,360 Serology Tests, 2015-2020.

Objectives: Lyme borreliosis incidence is increasing in several areas; moreover, it has recently gained the public's attention. Apart from erythema migrans, Lyme disease diagnosis relies (among others) on serology test; however, the prevalence of positive enzyme-linked immunosorbent assay (ELISA) and western blot (WB) assay has been poorly studied in the general population. We aimed to approach the seroprevalence of infection by Borrelia species responsible for Lyme disease in the French Isere department using city laboratories data. Patients and Methods: We retrieved all serological tests for Borrelia species responsible for Lyme disease performed in the two main networks of city laboratories between 2015 and 2020. All patients with both ELISA and WB IgG were considered seropositive. Results: We analyzed 27,360 tests (ELISA/ELISA+WB). Mean age was 50.9 ± 20.3 years (ranges: 0-101), with 57.1% females. Overall, 11.7% had IgG detected by ELISA, and 4.7% had IgG detected by both ELISA and WB assay. Seropositive status was more frequent in males (7.0% vs. 2.9%, p < 0.001). Seropositivity rate increased with age after a first peak in childhood; men aged 61-70 years had the highest seropositivity rate (10.3%). In addition, seropositivity rate was higher in persons from a rural area. In multivariate analysis, older age, male gender and living in a rural area were independently associated with seropositivity. Seropositivity rate was stable on the 2017-2020 period. Conclusion: The seroprevalence of infection by Borrelia species responsible for Lyme disease is high in Isere; this probably reduces the predictive positive value for Lyme disease of ELISA and WB IgG, suggesting that this serological test should not be performed for nonspecific symptoms.

Examination of Diagnostic Performance of New IgG4 Rapid Test Compared with IgG- and IgG4-ELISAs to Investigate Epidemiology of Strongyloidiasis in Northeast Thailand.

Strongyloidiasis, caused by Strongyloides stercoralis, is a neglected tropical disease with a global distribution. The infection can be fatal in immunocompromised individuals, and accurate diagnosis leading to timely treatment can save lives. Serodiagnosis is a sensitive method for diagnosis and is recommended for screening high-risk individuals. A point-of-care rapid test will facilitate the screening activities, especially in low-resource settings. This study aims to apply a new IgG4 immunochromatographic test using S. stercoralis recombinant antigen (SsRapid® cassette test) and to compare it with in-house IgG and IgG4 enzyme-linked immunosorbent assays (IgG- and IgG4-ELISAs) using native Strongyloides ratti antigen to investigate the epidemiology of strongyloidiasis in northeast Thailand. A total of 300 people participated, with 136 males and 164 females of a similar mean age. The reference tests were fecal examinations using the formalin-ethyl acetate concentration technique and an agar plate culture technique. The prevalence of S. stercoralis determined by SsRapid (81.7%) was significantly higher than that by fecal examinations (43.3%) or by antibody detection by IgG-ELISA (53.0%) or IgG4-ELISA (44.0%). The diagnostic sensitivities of SsRapid, IgG-ELISA, and IgG4-ELISA were found to be 93.9%, 77.7%, and 63.1%, respectively. The rate of positive tests by the SsRapid was significantly correlated to the levels of Strongyloides-specific IgG4 and IgG antibodies. By all diagnostic methods, male participants had a significantly higher prevalence of strongyloidiasis than females. Age was significantly associated with the concentration of specific serum IgG but not with the SsRapid grading score. In conclusion, SsRapid was shown to be a sensitive and valuable diagnostic test for the epidemiology study of strongyloidiasis.

Scrub typhus in Indonesia: A cross-sectional analysis of archived fever studies samples.

Scrub typhus is an understudied vector-borne bacterial infection. We tested archived fever samples for scrub typhus seropositivity to begin charting its geographic distribution in Indonesia. We analysed 1033 serum samples from three sites. IgM and IgG enzyme-linked immunosorbent assay (ELISA) against Orientia tsutsugamushi was performed using Karp, Kato, Gilliam, TA 716 antigens. To determine the cutoff in the absence of a presumed unexposed population and gold standard tests, we identified the visual inflection point, performed change point analysis, and used finite mixture models. The optical density cutoff values used for IgM and IgG were 0.49 and 0.13, respectively. Across all sites, IgM seropositivity was 4.6% (95% CI: 3.4 to 6.0%) while IgG seropositivity was 4.4% (95% CI: 3.3 to 5.8%). The overall seropositivity across sites was 8.8% (95% CI: 8.1 to 11.7%). The overall seropositivity for Jambi, Denpasar, Tabanan were 9.7% (95% CI: 7.0 to 13.3%), 8.0% (95% CI: 5.7 to 11.0%), 9.0% (95% CI: 6.1 to 13.0%), respectively. We conclude that O. tsutsugamushi exposure in humans occurred at all sites analysed and could be the cause of illness in some cases. Though it was not the main cause of acute fever in these locations, it is still important to consider scrub typhus in cases not responding to beta-lactam antibiotics. Future seroprevalence surveys and testing for scrub typhus in acute febrile illness studies will be essential to understand its distribution and burden in Indonesia.

Seroconversion and seroprevalence of TORCH infections in a pregnant women cohort study, Mombasa, Kenya, 2017-2019.

Women infected during pregnancy with TORCH (Toxoplasmosis, Other, Rubella, Cytomegalovirus, and Herpes simplex viruses) pathogens have a higher risk of adverse birth outcomes including stillbirth / miscarriage because of mother-to-child transmission. To investigate these risks in pregnant women in Kenya, we analyzed serum specimens from a pregnancy cohort study at three healthcare facilities. A sample of 481 participants was selected for TORCH pathogen antibody testing to determine seroprevalence. A random selection of 285 from the 481 participants was selected to measure seroconversion. These sera were tested using an IgG enzyme-linked immunosorbent assay against 10 TORCH pathogens. We found that the seroprevalence of all but three of the 10 TORCH pathogens at enrollment was >30%, except for Bordetella pertussis (3.8%), Treponema pallidum (11.4%), and varicella zoster virus (0.5%). Conversely, very few participants seroconverted during their pregnancy and were herpes simplex virus type 2 (n=24, 11.2%), parvovirus B19 (n=14, 6.2%), and rubella (n=12, 5.1%). For birth outcomes, 88% of the participant had live births and 12% had stillbirths or miscarriage. Cytomegalovirus positivity at enrolment had a statistically significant positive association with a live birth outcome (p=0.0394). Of the 10 TORCH pathogens tested, none had an association with adverse pregnancy outcome.

Serodiagnosis of Brucellosis in Patients with Fever of Unknown Origin at a Tertiary Care Hospital in Bangalore: A Cross-sectional Study

Introduction: Brucellosis is a zoonotic disease caused by bacteria of the genus Brucella. Although it is not commonly transmitted between humans, it can be transmitted through direct handling of cattle or their products, such as raw milk, unevenly heated milk, clotted cream, and cheese, for varying periods. Brucellosis is considered as one of the neglected zoonotic diseases worldwide, as it can cause debilitating acute infections and later become chronic with numerous complications. Aim: To determine the prevalence of brucellosis among patients with Pyrexia of Unknown Origin (PUO). Materials and Methods: This cross-sectional study was conducted in the Department of Microbiology at Ramaiah Medical College and Teaching Hospital in Bangalore, Karnataka, India, over a period of two years, from December 2019 to December 2021. The study included patients who visited the Outpatient Department (OPD) and those admitted to the hospital with fever persisting for more than 5-7 days and Fever of Unknown Origin (FUO). The total sample size was 180, and 5-10 ml of blood was collected from each patient under aseptic precautions from the median cubital vein for serological tests. The blood samples were stored at 2-8°C for the Rose Bengal Test (RBT) assay and Enzyme-Linked Immunosorbent Assay (ELISA). The demographic parameters considered included clinical history, age, gender, residency, and history of animal exposure. Data analysis was performed using the statistical software Statistical Package for the Social Sciences (SPSS) version 18.0, employing the Chi-Square test, Fisher’s-Exact test, and descriptive statistics. The significance level employed was set at p-value &lt;0.05. Results: Among 180 samples, six (i.e., 3.3%) were positive for the Brucella RBT (BRBT), while 11 (i.e., 6.1%) were positive for the (ELISA IgM), and 17 (i.e., 9.4%) were positive for the (ELISA IgG). Additionally, 22 samples (i.e., 12.22%) tested positive for either ELISA of IgG or IgM (ELISA IgG/IgM). Conclusion: The present study identified 22 patients (12.22%) with Brucella-positive cases who presented with various clinical signs and symptoms, originating from different geographical locations and regardless of gender. These findings suggest that all cases of FUO presented to a clinician should be evaluated for Brucella infection.

Seroprevalence of Human Brucellosis among Syrian Refugees in Jordan, 2022.

Brucellosis is prevalent in Mediterranean countries. The aim of this study was to determine the seroprevalence of brucellosis and associated factors among Syrian refugees in Jordan. A cross-sectional study was conducted among adult Syrian refugees who attended the Public Health Lab (PHL) in Al Mafraq governorate, during the period of May-June 2022 to obtain a health certificate, which is legally required to receive governmental authorization for employment in Jordan. Blood samples were obtained from participants and a serum specimen was tested for the presence of IgG antibodies against Brucella using enzyme-linked immunosorbent assay (ELISA) IgG kits (Vircell Microbiologists, Granada, Spain). A total of 1562 Syrian refugees were enrolled in the study. Their ages ranged between 18 and 74 years, with a median age of 30 years at presentation. The majority were males (75.9%, n = 1186) and 24.1% (n = 376) were females. The Brucella ELISA IgG results were positive for 149 persons, with an overall seroprevalence rate of 9.5% (95% confidence interval: 8.0%-11.0%). Having animal-related occupations, residing outside refugee camps, consuming unpasteurized milk, handling animals or their tissues, and slaughtering animals within 6 months of study inclusion were significantly higher among the seropositive group. In the multivariate analysis, IgG-positive persons were 13 times more likely to report being diagnosed with brucellosis (OR = 13.1, 95% CI: 6.1-28.3; p ≤ 0.001). In addition, they were more likely to reside in the city of Al Mafraq, as opposed to a refugee camp (OR = 1.9, 95% CI: 1.1-3.2; p = 0.025) and to have handled animals within 6 months of study inclusion (OR = 3.1, 95% CI: 1.1-8.9; p = 0.035). In conclusion, one-tenth of adult Syrian refugees were tested positive for Brucella ELISA IgG. Being diagnosed with brucellosis, residing in the city of Al Mafraq, as opposed to a refugee camp, and handling animals within 6 months of study inclusion were significantly associated with being positive for Brucella ELISA IgG. This study illustrates the need for improved brucellosis control measures via comprehensive vaccination of animals and enhanced laboratory detection and surveillance capacities, in addition to emphasizing the need for increased awareness sessions among Syrian refugees on the safe use and preparation of dairy products and safety practices of handling animals and their tissues.

SEROPREVALENCE OF IgG ANTIBODIES OF HUMAN TOXOCARIASIS AND ASOCIATED RISK FACTORS IN KHANH HOA PROVINCE

Background: Human toxocariasis is a zoonotic parasitic disease caused by Toxocara canis and T. cati roundworm larvae. While many studies have shown that dog and cat owners are at a higher risk of acquiring Toxocara spp. infection, there is no available evidence regarding the seroprevalence of Toxocara spp. infection among dog and cat owners in Khanh Hoa. Therefore, this study aims to investigate the prevalence of anti-IgG of Toxocara spp. infection and associated risk factors for visceral larval migrans among dog owners in three different areas of Khanh Hoa province..Subjects and methods: A descriptive cross-sectional study was conducted from 2022 to 2024 in three localities representing different socio-geographic areas (urban, rural, and mountainous) of Khanh Hoa province. A total of 1502 blood samples were collected from local individuals aged 5 to 75 for this study. Serum anti-T.canis IgG antibodies were detected using a commercial enzyme-linked immunosorbent assay (ELISA) kit: NovaLisaTM, Toxocara canis IgG ELISA. Simultaneously, a survey using structured questionnaire about information on risk factors associated with Toxocariasis was conducted among 720 people (aged 18 and over) from 1,502 individuals whose bloods were taken for testing.Results and conclusions: A total of 1,502 blood samples were examined for the presence of antibodies to dog and cat roundworm larval infection. Results revealed an overall positive rate of 57.66% across the three localities, with variations depending on geography. In Khanh Vinh, a mountainous district, the infection rate was 75.44%, and in its commune Khanh Trung, it was 81.20%. For the two urban wards, the rates were significantly lower (Phuoc Long Ward: 44.40% and Van Thanh Ward: 54.18%). A structured questionnaire was used to investigate risk factors among 720 individuals (aged 18 years old and over) out of the 1,502 individuals whose bloods were tested. Results indicated that 389 of them tested positive for the ELISA test. Infection rates varied among age groups: under 25 years old (6.94%), 25-50 years old (66.78%), and over 50 years old (37.28%). Notably, 49.87% of infected individuals owned dogs or cats, 93.32% regularly consumed raw vegetables, and 25.71% frequently handled dogs or cats. The high infection rate of dog and cat roundworm larvae in Khanh Hoa underscores the presence of several identified high-risk factors.

Safety and immunogenicity of ChAdOx1 nCoV-19 (AZD1222) vaccine in adults in Kenya: a phase 1/2 single-blind, randomised controlled trial.

There are limited data on the immunogenicity of coronavirus disease 2019 (COVID-19) vaccines in African populations. Here we report the immunogenicity and safety of the ChAdOx1 nCoV-19 (AZD1222) vaccine from a phase 1/2 single-blind, randomised, controlled trial among adults in Kenya conducted as part of the early studies assessing vaccine performance in different geographical settings to inform Emergency Use Authorisation. We recruited and randomly assigned (1:1) 400 healthy adults aged ≥18 years in Kenya to receive ChAdOx1 nCoV-19 or control rabies vaccine, each as a two-dose schedule with a 3-month interval. The co-primary outcomes were safety, and immunogenicity assessed using total IgG enzyme-linked immunosorbent assay (ELISA) against SARS-CoV-2 spike protein 28 days after the second vaccination. Between 28 th October 2020 and 19 th August 2021, 400 participants were enrolled and assigned to receive ChAdOx1 nCoV-19 (n=200) or rabies vaccine (n=200). Local and systemic adverse events were self-limiting and mild or moderate in nature. Three serious adverse events were reported but these were deemed unrelated to vaccination. The geometric mean anti-spike IgG titres 28 days after second dose vaccination were higher in the ChAdOx1 group (2773 ELISA units [EU], 95% CI 2447, 3142) than in the rabies vaccine group (61 EU, 95% CI 45, 81) and persisted over the 12 months follow-up. We did not identify any symptomatic infections or hospital admissions with respiratory illness and so vaccine efficacy against clinically apparent infection could not be measured. Vaccine efficacy against asymptomatic SARS-CoV-2 infection was 38.4% (95% CI -26.8%, 70.1%; p=0.188). The safety, immunogenicity and efficacy against asymptomatic infection of ChAdOx1 nCoV-19 among Kenyan adults was similar to that observed elsewhere in the world, but efficacy against symptomatic infection or severe disease could not be measured in this cohort. PACTR202005681895696 (11/05/2020).

Performance evaluation of heparin-induced platelet aggregation vs serotonin release assay.

Heparin-induced thrombocytopenia (HIT) is a rare but life-threatening condition that requires rapid diagnosis for proper management. Laboratory testing should only be performed on patients with intermediate- or high-risk pretest probability. The platelet factor 4 (PF4) enzyme-linked immunosorbent assay (ELISA) is the screening test that should be confirmed by higher specificity testing such as the heparin-induced platelet aggregation (HIPA) or the serotonin release assay (SRA). This study aims to evaluate the performance of the HIPA in comparison to the SRA, establish cutoffs of the PF4 ELISA to predict positivity for HIPA/SRA, and study the mortality rate between patients with suspected HIT confirmed as HIT positive vs negative. All positive PF4 ELISA cases with confirmatory HIPA and SRA testing were included. As the SRA was considered the gold standard, the HIPA performance was evaluated in comparison to SRA before and after the implementation of a new standardized interpretation guide in 2022. The mortality of these cases was also documented by chart reviews. In total, 232 cases with positive or indeterminate anti-PF4 IgG ELISA had confirmatory testing with HIPA and SRA. The sensitivity of the HIPA improved from 55.4% in 2018 to 2021 to 73.8% in 2022. The specificity remained similarly high in 2018 to 2021 vs 2022 (94.9% vs 87.5%). The negative predictive value (NPV) improved in 2022. The PF4 optical density cutoff to predict the positivity of SRA was 0.85 vs 1.47 to predict the positivity of HIPA but decreased to 0.83 when combining HIPA and/or SRA. There was no significant difference in mortality between patients with suspected HIT confirmed positive vs negative. Although the HIPA has a lower sensitivity than the SRA, the new standardized interpretation guide improved its sensitivity and NPV in 2022. Future improvements are needed to use the HIPA as a stand-alone confirmatory test with the goal to shorten hospital length of stay and expedite proper anticoagulation management.

Correlation of toxoplasmosis with small‑for‑gestational‑age newborns.

Toxoplasma gondii infection in pregnant women could lead to significant changes during the pregnancy, affect the outcomes of pregnancy and the timing of labour. Small‑for‑gestational‑age (SGA) newborns are defined by birthweight below the 10th percentile for gestational age. We tested an association between latent toxoplasmosis in pregnant women and deliveries of SGA babies. For testing, we included 1,647 women who gave birth to a singleton baby at ≥ 37 weeks of gestation. The complement-fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA) tests for IgG and IgM were used. The latent form of toxoplasmosis was defined as a CFT titre of 1:8 or higher, together with index positivity IgG ELISA > 1.1 and negative IgM. There were 406 (24.7 %) women positive, and 1,241 (75.3 %) women negative for latent toxoplasmosis. Of all deliveries. 190 were SGA‑positive and 1,457 were SGA‑negative. Our study found a statistically significant association between latent toxoplasmosis and SGA foetuses born at term. The Pearson chi-square model was statistically significant (χ2(1) = 7.365, p = .007). The odds ratio was 1.567. Pregnant women with latent toxoplasmosis giving birth at ≥ 37 weeks of gestation have a 1.567 times higher risk of delivering an SGA baby (Tab. 2, Fig. 1, Ref. 30).

Autoantibodies to beta tubulin in autoimmune liver diseases-Relation to pANCA and clinical relevance.

There was evidence that perinuclear antineutrophil cytoplasmic antibodies (pANCA) in autoimmune liver diseases react with human beta-tubulin-5 (TBB5). Here, we reevaluate the specificity and clinical relevance of anti-TBB5 antibodies. Patients with untreated autoimmune hepatitis (AIH; n = 53), AIH under immunosuppressive therapy (AIH-IS; n = 125), primary sclerosing cholangitis (PSC; n = 40), primary biliary cholangitis (PBC; n = 250), nonautoimmune liver diseases (n = 158), inflammatory bowel diseases (IBD; n = 30), and healthy individuals (n = 62) were tested by enzyme-linked immunosorbent assay for IgG- and IgA-antibodies against recombinant human TBB5. pANCA were detected by immunofluorescence test. Sera were absorbed with TBB5 coupled to cyanogen bromide-activated sepharose. Prevalence and reactivity of IgG anti-TBB5 were significantly higher in patients with untreated AIH (68%; arbitrary units [AU] median: 369) than in PSC (28%; AU median: 84, P < 0.001), other liver diseases (14%; AU median: 185, P < 0.0001), IBD (3%; AU median: 111, P < 0.0001), and healthy controls (3%; AU median: 135; P < 0.0001). Anti-TBB5 did not correlate with pANCA, and immunoprecipitation with TBB5 did not abolish pANCA reactivity. In untreated AIH, anti-TBB5-reactivity was significantly higher than in AIH-IS. Transaminases decreased under IS preferentially in anti-TBB5-negative patients. There was no correlation between anti-TBB5-reactivity and histological stages. IgA-anti-TBB5 was mainly found in alcohol-associated liver disease (ALD; 39%). Our data do not support TBB5 as an autoantigenic target of pANCA. However, IgG-anti-TBB5 showed high specificity for (untreated) AIH. While they did not correlate with histological and laboratory parameters, their presence may indicate a poor response to IS.

SEROEPIDEMIOLOGY AND RISK FACTORS OF HUMAN TOXOPLASMOSIS IN ERBIL, KURDISTAN REGION, IRAQ

Introduction: This study aimed at the detection of anti-Toxoplasma. gondii antibodies in human blood samples using immunological tests and to investigate the potential risk factors. Methods: Five hundred and twenty samples were collected from individuals aged between 10 to 71 years old. All samples were tested by latex, lateral flow assay, and Enzyme-linked immunosorbent assay (ELISA). Personal data which may be potential risk factors were collected. Results: Out of the 520 Blood samples tested, 23.3%, 25.4%, 20.2%, and 9.8% had positive results for latex, lateral flow assay, ELISA IgG, and ELISA IgM, respectively. The prevalence of T. gondii antibody was high in the elderly age group that had a seropositive result of 26.1%,27.5%, and 23.2% for latex, lateral flow assay, and ELISA IgG, respectively. Conclusion:The two major risk factors associated with the infection are contact with raw meats and consumption of raw vegetables.Latex and lateral flow assay for diagnosis of T. gondii in routine screening might be a cost-effective testing strategy. Consumers are recommended to heat the food of animal origin, and wash all vegetables and fruit carefully before consumption.

Longitudinal comparison of bacterial pathogen seropositivity among wet market vendors in the Lao People's Democratic Republic

Wild animal trade for human consumption is a global issue, involving complex interactions between economics, culture, food security and conservation. Whilst being a biodiversity issue, it is also a major public health concern, with recent epidemics and pandemics of zoonotic pathogens linked to interactions with wildlife. At three time points, between March 2017 and June 2018, a longitudinal sero-survey of 150 market vendors from three wet markets in Laos (selling vegetables, domestic animal meat and/or wildlife meat) was conducted to determine if vendors had been differentially exposed to three endemic bacterial pathogens – Orientia tsutsugamushi, Rickettsia typhi, and Leptospira spp. A total of 367 serum samples were tested by IgG enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA, for scrub typhus group (STG) and typhus group (TG) only). Among vendors, 32.7% were IgG-positive for at least one pathogen, 13.3% sero-converted during the study. Multi-season occupancy modelling for STG indicated a significantly higher prevalence of STG IgG in vegetable vendors (27.3%) and wildlife vendors (28.4%) than in domestic animal meat vendors (6.9%, p = 0.05), and higher in Phonsavanh market (OR = 9.6, p = 0.03) compared to Lak Sao and Salavan markets. Estimated mean incidence was 57 cases per 10,000 per 7.5-month period. For TG, vendor age had a significant effect on prevalence (OR = 1.04, p = 0.006), estimated mean incidence was 64 cases per 10,000 per season (7.5-month period). Despite individuals selling domestic meat having a higher prevalence of Leptospira infections than those that did not (11.6% versus 4.5%), the difference was not significant. Whilst this study has a number of limitations, including vendors changing what food types they sold and no investigation of exposure outside of markets, the finding that the risk of exposure of vendors to zoonotic pathogens may be associated with types of food sold for human consumption warrants further investigation.

Human Brucellosis: An Observational Study From a Tertiary Care Centre in North India.

The main aim/objective of this study was to detect and characterize theBrucella speciesfrompatients having complaints of joint pain and also to know thepotential causes of human brucellosis. In our study, we focused on joint pain symptoms that may be due to arthralgia or arthritis. Introduction: Brucellosis is a neglected zoonotic disease that affects both humans and animals.In humans, brucellosis begins with chronic illness leading to greatfinanciallosses fromnot being able to work welland continued treatment costs, butfew such studies have come from northern India.Joint pain is the common presentation of brucellosis and there are several risk factors associated with brucellosis. A total of 200 blood samples were collected from the participants having joints pain from September 2019 to September 2021 at Gandhi Memorial & Associated Hospitals ofKing George's Medical University, Lucknow, India, and tested by serology for anti-BrucellaIgM and IgG enzyme-linked immunosorbent assay (ELISA),moleculartests byreverse transcriptase-polymerase chain reaction (RT-PCR),conventional polymerase chain reaction (PCR), and automated blood culture system.The anti-Brucella IgM and IgG ELISA were performed using the kit from NovaTec Immundiagnostica GmbH (Dietzenbach, Germany). Isolation of DNAwas carried out using the QIAamp DNA Mini kit (QIAGEN,Hilden, Germany), and the primers and probes specific for targeted regions (BCSP31 and IS711 gene)in theBrucellagenome were procured from Eurofins Scientific SE (Luxembourg, France), and for internal control from CDC. The study showed 19(9.5%) and 23 (11.5%) positive results by anti-BrucellaIgM ELISA and anti-BrucellaIgG, respectively, andof these, one (0.5%) was positive for both anti-BrucellaIgM and anti-BrucellaIgG ELISA.Out of 19 anti-Brucella IgM ELISA positive, eight (4%) samples were positive forPCR/RT-PCRandthat was negative for anti-Brucella IgG ELISA. All blood culture reports of all patients were negative. Conclusion: Anti-Brucella IgM ELISA was more accurate than anti-Brucella IgG ELISA in detecting human brucellosis. Consumption of animal products(i.e. milk, a dairy product of cow, buffalo, goat, and meat of goat)and contact with animals were themain risk factors that were identifiedfor Brucelladisease.

Identification of prior dengue-naïve Dengvaxia recipients with an increased risk for symptomatic dengue during fever surveillance in the Philippines.

Dengue virus (DENV) is the leading cause of mosquito-borne viral diseases in humans. Dengvaxia, the first licensed dengue vaccine, is recommended for DENV-seropositive individuals aged 9-45 years. In the Philippines, Dengvaxia was administered to more than 830,000 children without prior serological testing in 2016-2017. Subsequently, it was revealed that DENV-seronegative children who received Dengvaxia developed severe disease following breakthrough DENV infection. As a result, thousands of children participating in the mass vaccination campaign were at higher risk of severe dengue disease. It is vital that an assay that identifies baseline DENV-naïve Dengvaxia recipients be developed and validated. This would permit more frequent and extensive assessments and timely treatment of breakthrough DENV infections. We evaluated the performance of a candidate assay, the DENV1-4 nonstructural protein 1 (NS1) IgG enzyme-linked immunosorbent assay (ELISA), developed by the University of Hawaii (UH), using well-documented serum/plasma samples including those >20 years post-DENV infection, and tested samples from 199 study participants including 100 Dengvaxia recipients from the fever surveillance programs in the Philippines. The sensitivity and specificity of the assay were 96.6% and 99.4%, respectively, which are higher than those reported for pre-vaccination screening. A significantly higher rate of symptomatic breakthrough DENV infection was found among children that were DENV-naïve (10/23) than among those that were DENV-immune (7/53) when vaccinated with Dengvaxia (p=0.004, Fisher's exact test), demonstrating the feasibility of the assay and algorithms in clinical practice. The UH DENV1-4 NS1 IgG ELISA can determine baseline DENV serostatus among Dengvaxia recipients not only during non-acute dengue but also during breakthrough DENV infection, and has implications for assessing the long-term safety and effectiveness of Dengvaxia in the post-licensure period.