Evaluating the Status of Hepatitis B Vaccination in Healthcare Workers at a Central Laboratory in a Tertiary Care Hospital and Research Centre.

Introduction Hepatitis B virus is a significant occupational hazard for healthcare workers worldwide. Long-term protection against hepatitis B infection is conferred by the vaccine and the protective immune response is indicated by anti-hepatitis B surface antigen (HBsAg) titre. It is crucial to monitor anti-HBsAg titres as their levels decrease over time. The study aims to evaluate the status of hepatitis B vaccination among personnel working in the Central Laboratory of Shri B.M. Patil Medical College Hospital and Research Centre. The focus is on understanding the immunization practices and protection levels against HBV within this high-risk group. Materials and methods A cross-sectional analysis was conducted, including collecting demographic data, determining HBsAg status, evaluating anti-HBsAg titre value, and getting vaccination details of the laboratory personnel. The study participants included doctors, lab technicians, and attendants who were assessed for both vaccination coverage and immunity levels. After obtaining their written consent, 4 ml of blood was collected in sterile blood collection tubes. All the samples were tested for HBsAg. The negative samples were tested for anti-hepatitis B surface antigen antibody (HBsAg-Ab (IgG)) titre. The enzyme-linked immunosorbent assay (ELISA) method was used to evaluate the obtained samples for HBsAg and anti-HBsAg titre. Results A total of 99 healthcare workers were included in the study. Most of the laboratory healthcare workers were in the age range of 20-30 years. In 84.8% of the subjects, protective antibody levels (>10 IU/ml) were found. The highest protection was seen among doctors (94.5%), followed by lab technicians (82.9%) and attendants (66.6%). However, 15.2% exhibited inadequate immunity, predominantly among the attendants (33.3%). The highest vaccination coverage was among doctors (91.8%), followed by lab technicians (78.7%) and attendants (53.3%). Most doctors had completed the full vaccination schedule (70.2%) or received a booster dose (24.3%) compared to lab technicians (57.4%) and attendants (46.6%). Conclusion The study highlights effective preventive measures against HBV among laboratory healthcare workers, as indicated by the absence of active infections. But it also emphasizes the necessity of focused initiatives to raise vaccination rates, particularly among attendants, in order to guarantee complete protection against HBV for all levels of laboratory workers.

Evaluation of the Diagnostic Performances of the SD-Bioline®HBeAg Rapid Test Used Routinely for the Management of HBV-Infected Individuals in Burkina Faso.

Hepatitis B e antigen (HBeAg) is a marker of wild-type hepatitis B virus replication. In resource-limited countries where access to enzyme-linked immunosorbent assay (ELISA) remains a challenge, rapid diagnostic tests (RDT) constitute a good alternative. The HBeAg status is employed to evaluate eligibility for antiviral therapy and to prevent the transmission of hepatitis B from mother to child (PMTCT). The objective of this study was to assess the diagnostic performance of the SD-Bioline®HBeAg RDT commonly used for detecting HBeAg in laboratories in Burkina Faso. The sample panel used was collected from HBsAg-positive patients received in the laboratory for the detection of HBeAg with the rapid test. The samples were retested for HBeAg using the VIDAS HBe/Anti-HBe enzyme-linked fluorescent assay (ELFA) (Gold standard). Then, the viral load (VL) of HBV DNA was determined using the GENERIC HBV CHARGE VIRLAE kit (GHBV-CV). The diagnostic performances of the SD-Bioline®HBeAg and its agreement with the gold standard were calculated with their 95% confidence intervals. Overall, 340 sera obtained from HBsAg-positive patients were included in this evaluation Compared to the VIDAS HBe/Anti-HBe ELFA test, the sensitivity (Se) and specificity (Sp) of the SD-Bioline®HBeAg test were 33.3% and 97.9%, respectively. The concordance between the two tests was 0.42. Depending on the viral load, the Se and Sp varied from 8.8% and 98.3% for a VL < 2000 IU/mL to 35.5% and 98.4% for a VL > 2,000,000 IU/mL. The results showed a low sensibility of the SD-Bioline®HBeAg RDT test, indicating that its use is inappropriate for the clinical management of HBV-infected patients. They also highlight the urgent need to develop HBeAg rapid tests with better sensitivities.

Redox Cycling Amplified Electrochemical Lateral-Flow Immunoassay: Toward Decentralized Sensitive Insulin Detection.

While paper-based lateral-flow immunoassays (LFA) offer considerable promise for centralized diagnostic applications, the analytical capability of conventional LFA remains constrained due to the low sensitivity of its common optical detection strategy. To address these issues, we report a simple electrochemical LFA (eLFA) with nanocatalytic redox cycling for decentralized insulin detection. Simultaneous binding of insulin with detection antibodies and capture antibodies through the capillary flow at the LFA platform and signal amplification through the rapid nanocatalytic reduction of [Fe(CN)6]3- (Fe3+) with Au nanoparticles (AuNP) and ammonia-borane (AB), coupled to electrochemical redox cycling reactions involving Fe3+, AuNP, and AB on the carbon working electrode, offer higher sensitivity than conventional colorimetric LFA and enzymatic redox cycling. The resulting integrated eLFA strip allows the detection of low insulin concentrations (LOD = 12 pM) and offers considerable promise for highly sensitive decentralized assays of different biological fluids (saliva and serum) without additional pretreatment or washing steps.

Performance Evaluation of VIDAS® Diagnostic Assays Detecting Anti-Chikungunya Virus IgM and IgG Antibodies: An International Study.

Chikungunya (CHIK) is a debilitating mosquito-borne disease with an epidemiology and early clinical symptoms similar to those of other arboviruses-triggered diseases such as dengue or Zika. Accurate and rapid diagnosis of CHIK virus (CHIKV) infection is therefore challenging. This international study evaluated the performance of the automated VIDAS® anti-CHIKV IgM and IgG assays compared to that of manual competitor IgM and IgG ELISA for the detection of anti-CHIKV IgM and IgG antibodies in 660 patients with suspected CHIKV infection. Positive and negative agreements of the VIDAS® CHIKV assays with ELISA ranged from 97.5% to 100.0%. The sensitivity of the VIDAS® CHIKV assays evaluated in patients with a proven CHIKV infection confirmed reported kinetics of anti-CHIKV IgM and IgG response, with a positive detection of 88.2-100.0% for IgM ≥ 5 days post symptom onset and of 100.0% for IgG ≥ 11 days post symptom onset. Our study also demonstrated the superiority of ELISA and VIDAS® assays over rapid diagnostic IgM/IgG tests. The analytical performance of VIDAS® anti-CHIKV IgM and IgG assays was excellent, with a high precision (coefficients of variation ≤ 7.4%) and high specificity (cross-reactivity rate ≤ 2.9%). This study demonstrates the suitability of the automated VIDAS® anti-CHIKV IgM and IgG assays to diagnose CHIKV infections and supports its applicability for epidemiological surveillance and differential diagnosis in regions endemic for CHIKV.

Protocols for D-Dimer Measurements for Aid to Diagnosis or Exclusion of Venous Thromboembolism.

Measuring D-dimer is commonly used as a surrogate to indicate a clot-forming process, with subsequent lysis. This test has two primary intended uses: (1) as aid to diagnosis of various conditions and (2) venous thromboembolism (VTE) exclusion. If the manufacturer cites a VTE exclusion claim, the D-dimer test must only be used in evaluating patients with a non-high or unlikely pretest probability for pulmonary embolism and deep vein thrombosis. D-dimer kits with only aid to diagnosis claim should not be used for VTE exclusion. The intended use of the D-dimer may vary by region, and readership should consult manufacturer instructions for use to assure proper use of the assay. In this chapter, several methods for measuring D-dimer will be described.

Effects of combined metformin and cabergoline versus metformin alone on ovarian and hormonal activities in Iraqi patients with PCOS and hyperprolactinemia: a randomized clinical trial.

Polycystic ovary syndrome (PCOS) is one of the most prevalent metabolic diseases during female reproductive life, often associated with insulin resistance and hyperprolactinemia. The efficacy of metformin and cabergoline for managing PCOS remains debated in the literature. This three-arm interventional study in Iraq assessed the effects of these drugs on body mass index (BMI), hormonal balance, and uterine artery blood flow in 75 women with PCOS and hyperprolactinemia. Participants were randomized into three groups: metformin (500 mg twice daily), cabergoline (0.5 mg weekly), and a combination of both, with 25 patients in each group. Baseline and 90-day follow-up characteristics included BMI, serum hormonal levels, and ultrasound features. Metformin resulted in significant weight reduction (p=0.038); however, the addition of cabergoline caused a more significant reduction in body mass index (p=0.001). The combined treatment significantly lowered testosterone levels (p=0.008). In addition, this combination significantly reduced the level of LH (p=0.043) and increased the level of FSH (p=0.047). The results suggest that metformin and cabergoline when used together, act synergistically and safely to reduce BMI, testosterone, and LH levels while increasing FSH levels. Furthermore, this combination improved endometrial blood flow and ovulation in women with PCOS.

Frequency of natural antibodies and concordance analysis for anti-TOXOPLASMA IgM tests in Colombian sera of pregnant women.

Interpretation of IgM anti-Toxoplasma can be problematic given the phenomena of "natural" IgM. We analyzed 1,503 sera obtained during prenatal care program, and we established natural and false-positive results by doing follow-up. In 101 samples the concordance between enzyme linked immunosorbent assay (ELISA) and two semi-automatized systems: electro-chemiluminescence immunoassay (ELECSYS) and vitek immunodiagnostic assay system (VIDAS) was calculated. In 1,503 serum, 71 (4,7%) had ELISA IgG negative and ELISA IgM positive results and in 44 of these had a second sample 4 weeks later. In second samples, 27 (61,3 %) were IgM and IgG negative (false positive result in the first sample) and 13 (29,5%) were ELISA IgM positive and IgG negative (natural IgM). ELISA assay had a poor concordance with enzyme-linked fluorescent immunoassay as well as ELECSYS tests, contrarily, enzyme-linked fluorescent immunoassay and ELECSYS had optimal concordance, with 100 of 101 sera obtaining the same result by both tests. We recommended to use automatized assays to measure IgM anti-Toxoplasma.

Seroprevalence of Toxoplasma gondii in Different Patient Groups in Our Hospital

Objective: Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. It is regarded as an important cause of morbidity and mortality in congenital contamination and immunosuppressive patients. This study aimed to determine the seropositivity of T. gondii in various ages and patient groups, as well as to reveal the current immune status, especially in risk groups. Methods: Results of T. gondii serology conducted between 2015 and 2019 in the medical microbiology laboratory in a university hospital were retrospectively analyzed. In the study, anti-T. gondii IgM, anti-T. gondii IgG antibodies, and anti-T. gondii IgG avidity test results were investigated by the enzyme-linked fluorescent assay method. Additionally, seropositivity rates among immunosuppressed patients and pregnant women, which are risk groups for toxoplasmosis, were revealed. In the identification of the immunosuppressed patients, groups with significant immunosuppression were retrospectively determined by examining their files. Results: The serology of T. gondii was investigated in serum samples of a total of 20.875 individuals, among which 6.220 (29.8%) are males and 14.655 (70.2%) are females. Anti-T. gondii IgM and IgG positivity rates were significantly higher in women than in men. When all years are evaluated, IgM positivity in 16.448 patients and IgG positivity in 4.427 patients were investigated. In the 5-year period, T. gondii IgM seropositivity and T. gondii IgG seropositivity was among all the patients was 2.4% and 24.1%, respectively. While the rate of T. gondii IgG seropositivity in women of childbearing age was 36.1%, it was 42.4% in pregnant women and 14.6% in immunosuppressed patients. Conclusion: T. gondii serology follow-up of pregnant women and immunosuppressed patients in terms of reactivity of latent infection should be advised and toxoplasmosis should be considered in suspicious clinical cases.

Rapid detection of Campylobacter spp. in chickens before slaughter.

Campylobacter continues to be the number one cause of bacterial gastroenteritis in Europe. Poultry, and especially broiler chickens, is considered an important reservoir for Campylobacter spp. Poultry producers prioritize to identify and reduce the number of Campylobacter contaminated chicken flocks by tightening biosecurity and mitigation actions at slaughter. Campylobacter-positive flocks must therefore be identified as close to slaughter as possible, and rapid detection methods are needed. Here we evaluated the applicability, sensitivity, and specificity of four commercially available rapid methods to detect Campylobacter in naturally contaminated chicken cecal droppings on-farm before slaughter against an established qPCR method. The Biofire® FilmArray® Gastrointestinal Panel assay, the VIDAS Campylobacter assay, the Singlepath® Campylobacter test, and OptiGenes' Genie Campylobacter isothermal DNA amplification were assessed in a pilot-study. The OptiGenes' Genie Campylobacter isothermal DNA amplification was also tested under field conditions. The Biofire® FilmArray® showed superior sensitivity and specificity compared to the three other rapid tests but had a lower throughput and a higher cost. While the VIDAS Campylobacter, Singlepath® Campylobacter and the isothermal DNA amplification were affordable, their unsatisfactory sensitivity (10%-71%) left these unsuitable to monitor Campylobacter carriage in chickens. An additional finding of this study is that 38% of flocks positive for Campylobacter at slaughter became contaminated during the last week of rearing. Therefore, increased efforts to develop suitable methods to detect Campylobacter rapidly and reliably in chickens close to slaughter are needed.

Prevalence of HIV and hepatitis B virus among pregnant women in Luanda (Angola): geospatial distribution and its association with socio-demographic and clinical-obstetric determinants.

BACKGROUND: HIV and HBV infections remain responsible for high rate of morbidity and mortality in many African Countries, affecting women and newborns. This study aims to analyze the spatial pattern of HIV and HBV infections in pregnant women in Luanda, Angola, and the statistical association between HIV and HBV and socio-economic characteristics, hygiene, and health status. METHODS: Detection of anti-HIV antibodies (total anti-HIV-1, anti-HIV-2 and HIV-1 p24 antigen) and Hepatitis B antigens (HBsAg, HBeAg) and antibodies (anti-HBc Total II, HBc IgM, Anti-HBsT II) was performed by Enzyme Linked Fluorescent Assay (ELFA) in serum samples of 878 pregnant women attended at the Lucrecia Paim Maternity Hospital (LPMH). Data were collected by questionnaire after written consent, and spatial distribution was assessed through a Kernel Density Function. The potential risk factors associated with HIV HBV infection were evaluated using bivariate and multivariate binomial logistic regression analysis. RESULTS: Anti-HIV antibodies were positive in 118 samples (13.4%) and HBV infection were positive in 226 (25.7%). The seroprevalence of HIV/HBV coinfection was of 6.3%. The results showed that the seroprevalence of HBV was similar in most municipalities: 25.8% in Belas; 26.6% in Viana; 27.6% in Luanda; 19.2% in Cacuaco; and 15.6% Cazenga. For HIV, the seroprevalence was also close ranges among the municipalities: 10.0% in Belas; 14.5% in Viana 14.9% in Luanda and 12.5% in Cazenga. However, the seroprevalence in municipality of in Cacuaco was lower (5.8%) and bivariate and multivariate analysis showed a lower risk for HIV in this area (OR 0.348, CI 0.083-0.986; OR 0.359, CI 0.085-1.021). The multivariate analysis had also showed a significant increased risk for HIV in women with 2 or 3 births (OR 1.860, CI 1.054-3.372). CONCLUSIONS: Our results underlined the need to improve the screening and clinical follow-up of HIV and HBV in Angola, as well the educational campaigns to prevent not only the morbidity and mortality associated with these diseases, but also their transmission, mainly in women in reproductive age and pregnant, encouraging the pre-natal consultations in order to avoid mother-to-child transmission.

CAN IgG ANTIBODIES DIRECTED AGAINST DIFFERENT TARGETS SOLVE THE PROBLEM OF FALSE-POSITIVE RESULTS IN SARS-CoV-2 SEROLOGY?

In addition to RT-PCR assays, serology testing that has been recognized as a useful tool to assess the spread of infection in the population is considered successful and important strategy in the control of the global pandemic of SARS-CoV-2 infection. Now, a great number of manufacturers offer their serologic tests on the market. When interpretating the results, the rate of seroprevalence should be taken in consideration because it may influence the positive predictive value, as well as cross-reactivity with other coronaviruses in case of assays with poorly designed antigens. We present results of 11 patients with different clinical background and tested with two different serologic tests, DIAPRO (ELISA; Sesto San Giovanni, Italy) and VIDAS (ELFA; BioMerieux, Marcy I'Etoile, France). The results obtained by the former test showed ten of these patients to be IgG positive and one patient was IgG weakly positive with different confidence index. The latter test discriminated positive results with medium confidence index on the former test as negative. The results obtained with two serology tests were concordant with the observation that the results with medium confidence index may indicate cross-reactivity.

Effect of heat treatment on activity of staphylococcal enterotoxins of type A, B, and C in milk.

Intoxication by staphylococcal enterotoxins (SE) is among the most common causes of food-poisoning outbreaks resulting from the consumption of raw milk or products made thereof. The aim of our study was to analyze the thermal stability of SE and evaluate the inactivation of SE types A, B, and C (SEA, SEB, SEC) by autoclaving at 100°C, 110°C, and 121°C. Milk samples were inoculated with 38 Staphylococcus aureus strains that possessed the ability to produce SEA, SEB, or SEC and incubated at 37°C for 24 h. This incubation was followed by heat treatment at 100°C, 110°C, or 121°C for 3 min. Samples were analyzed by Staph. aureus plate count method on Baird-Parker agar and specifically for the presence of SE. An enzyme-linked immunofluorescent assay (ELFA) on a MiniVIDAS analyzer (bioMérieux, Marcy l'Étoile, France) was used to detect SE, which were determined semi-quantitatively based on test values. The obtained results were analyzed by means of nonparametric statistical methods. All samples (100%; 38/38) were SE-positive before heat treatment, and the positivity rates decreased after heat treatment at 100°C, 110°C, and 121°C to 36.8% (14/38), 34.2% (13/38), and 31.6% (12/38), respectively. The rates of positive samples differed between SEA, SEB, and SEC producers: SEA was detected in the highest amounts both before and after heat treatment. The amount of SE (expressed as test values) decreased significantly after heat treatment. Comparing amounts of SE in positive and negative samples before and after heat treatment, we can conclude that the success of SE inactivation depends on the amount present before heat treatment. The highest amount of SE and the highest rate of SE-positive samples after all heat treatments were found in samples with strains producing SEA. For SEB and SEC, lower amounts of enterotoxin were present and were inactivated at 100°C. Although temperatures of 100°C, 110°C, and 121°C may inactivate SE in milk, the key measures in prevention of staphylococcal enterotoxicosis are avoiding initial contamination of milk by Staph. aureus, promoting consumption of heat-treated milk, and preventing disruption of the cold chain during milk production and processing.

Evaluation and validation of an alternative method to detect Campylobacter spp. in dairy products.

Foods implicated in human campylobacteriosis include raw or undercooked poultry and raw dairy products. Because Campylobacter spp. are the most frequently reported cause of bacterial infection in the European Union and because conventional methods are cumbersome, rapid methods for Campylobacter detection and quantification in food are needed. With this study we sought to validate, according to the standard procedure (UNI EN ISO 16140:2003), an alternative to the reference analytical method (UNI EN ISO 10272-1:2006) for official controls of Campylobacter spp. in raw milk and dairy products. Milk samples collected from 16 milk vending machines located throughout the Genoa metropolitan area were analyzed using two different methods, an enzyme-linked fluorescent assay (ELFA) and a real-time PCR assay, and evaluated in parallel against the reference method. In addition, a total of 460 samples of raw milk collected from milk vending machines were analyzed by ELFA. Results obtained with ELFA showed it was compliant with UNI EN ISO 10272-1:2006 criteria and that the immunoassay had 100% sensitivity, specificity, and accuracy. Regarding samples of milk vending machines, 5.0% (23/460) tested positive at ELFA screening and were subsequently confirmed as C. jejuni. Validation according to UNI EN ISO 16140:2003 of the ELFA method suggests it may be a useful alternative to conventional methods for detecting Campylobacter spp. in official controls.

Rapid detection of Salmonella sp. in pork samples using fluorescent in situ hybridization: a comparison with VIDAS®-SLM system and ISO 6579 cultural method / Detecção rápida de Salmonella sp. em amostras de suinos por hibridação in situ fluorescente: comparação com o sistema VIDAS®-SLM e com o método de cultura ISO 6579

This study reports the use of the fluorescent in situ hybridization (FISH) with Sal3 probe for Salmonella detection in swine carcasses inner surface (swab); and in the correspondent samples of ileum, ileocolic, and mandibular lymph nodes; and tonsils, after dilution (1:10) in buffered peptone water and a pre-enrichment step (37(0)C, 18h). In order to evaluate the efficiency of FISH, 235 naturally contaminated samples were simultaneously tested by the cultural method (ISO 6579) and by the Vitek Immuno Diagnostic Assay System (VIDAS®) - Salmonella (SLM) system. The cultural method identified 39 positive samples. From these, VIDAS®- SLM only detected 23. FISH identified 115 positive samples. This difference was highly significant (P<0.001). From positive samples, 32 were also confirmed by the cultural method. The results indicate FISH as a promising tool for rapid Salmonella detection in samples of pork and swine carcasses

Descreve-se a utilização da técnica de hibridação in situ fluorescente (FISH), utilizando a sonda Sal3, para detecção de Salmonella na superfície interna de carcaças de suínos (zaragatoa), em amostras correspondentes de íleo, linfonodos ileocólicos, linfonodos mandibulares e amígdalas, após terem sido diluídas (1:10) e submetidas a uma fase de pré-enriquecimento em água peptonada tamponada (a 37ºC, 18h). Para avaliar a eficácia do método FISH, analisaram-se 235 amostras naturalmente contaminadas, usando o método de cultura ISO 6579 e o sistema Vitek Immuno Diagnostic Assay System (VIDAS®)- Salmonella (SLM), simultaneamente. O método de cultura identificou 39 amostras positivas, das quais o método VIDAS®-SLM detectou apenas 23. O método FISH identificou 115 amostras positivas. A diferença entre os métodos foi altamente significativa (P<0.001). Das amostras positivas, 32 foram confirmadas pelo método de cultura. Os resultados indicam que a FISH constitui uma promissora técnica de detecção rápida de Salmonella em amostras de suínos abatidos para consumo

Interferência da riboflvina (vit. B2) nas análises fluorométricas modernas (relato de 3 casos): nota prévia / Interference of the riboflavin in the fluorometric analysis

A emissão de forte fluorescência da riboflavina (vit. 82) pode interferir nas análises fluorimétricas qualitativas fornecendo resultados falso-positivos nos exames sorológicos, após ingestão de polivitamínicos (relato de 3 casos).

Evaluation of an Automated Enzyme-Linked Fluorescent Immunoassay System for the Detection of Salmonellae in Foods.

An automated qualitative enzyme-linked fluorescent immunoassay was compared to a conventional method outlined in the FDA Bacteriological Analytical Manual for the detection of salmonellae in artificially contaminated milk, whey, and carbohydrate-based products. The evaluation parameters included sensitivity and specificity using pure cultures of Salmonella typhimurium , Salmonella tennessee , and Citrobacter freundii and mixtures of these species to address the effect of competing microflora. The overall detection rate of the conventional method was 97% compared to a detection rate of 96% for the automated system. The conventional method sensitivity rate was 97% for the detection of pure cultures of Salmonella typhimurium and Salmonella tennessee . The automated system sensitivity rate was 96%. The sensitivity rates in the presence of competing microflora for the conventional method and automated system were 96 and 95% respectively. Both the conventional and automated system specificity rates were 100% when challenged with pure cultures of Citrobacter only. Blackburn et al. (Lett. Appl. Microbiol. 19:32-36, 1994) had previously evaluated the VIDAS (Vitek Immuno Diagnostic Assay System) Salmonella Assay using pure cultures of salmonellae in laboratory media. This study addresses the use of the VIDAS for detecting salmonellae when examining complex food matrices.