scholarly journals Towards a New Strategy for Diagnosis of Congenital Trypanosoma cruzi Infection

2017 ◽  
Vol 55 (5) ◽  
pp. 1396-1407 ◽  
Author(s):  
Alba Abras ◽  
Carmen Muñoz ◽  
Cristina Ballart ◽  
Pere Berenguer ◽  
Teresa Llovet ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Latin American ◽  
Serological Test ◽  
Igg Antibodies ◽  
Childbearing Age ◽  
Serological Tests ◽  
Content Type ◽  
Congenital Transmission ◽  
Screening Programs ◽  
New Strategy

ABSTRACTThe immigration of Latin American women of childbearing age has spread the congenital transmission of Chagas disease to areas of nonendemicity, and the disease is now a worldwide problem. Some European health authorities have implemented screening programs to prevent vertical transmission, but the lack of a uniform protocol calls for the urgent establishment of a new strategy common to all laboratories. Our aims were to (i) analyze the trend of passive IgG antibodies in the newborn by means of five serological tests for the diagnosis and follow-up of congenitalTrypanosoma cruziinfection, (ii) assess the utility of these techniques for diagnosing a congenital transmission, and (iii) propose a strategy for a prompt, efficient, and cost-effective diagnosis ofT. cruziinfection. In noninfected newborns, a continuous decreasing trend of passive IgG antibodies was observed, but none of the serological assays seroreverted in any the infants before 12 months. From 12 months onwards, serological tests achieved negative results in all the samples analyzed, with the exception of the highly sensitive chemiluminescent microparticle immunoassay (CMIA). In contrast, in congenitally infected infants, the antibody decline was detected only after treatment initiation. In order to improve the diagnosis of congenitalT. cruziinfection, we propose a new strategy involving fewer tests that allows significant cost savings. The protocol could start 1 month after birth with a parasitological test and/or a PCR. If negative, a serological test would be carried out at 9 months, which if positive, would be followed by another at around 12 months for confirmation.

scholarly journals Etiological treatment of young women infected with Trypanosoma cruzi, and prevention of congenital transmission

2009 ◽  
Vol 42 (5) ◽  
pp. 484-487 ◽  
Author(s):  
Sergio Sosa-Estani ◽  
Estela Cura ◽  
Elsa Velazquez ◽  
Cristina Yampotis ◽  
Elsa Leonor Segura
Keyword(s):  
Trypanosoma Cruzi ◽  
Young Women ◽  
Serological Tests ◽  
Congenital Transmission ◽  
Cruzi Infection ◽  
Efficacy Of Treatment

The objective was to detect Trypanosoma cruzi infection in 32 children in Salta, Argentina, born to 16 chronically infected young women who were treated with benznidazole. Tests were performed to assess the efficacy of treatment after 14 years. At the end of the follow up, 87.5% of the women were non-reactive to EIA tests, 62.5% to IHA and 43.8% to IFA. 62.5% of the women were non-reactive according to two or three serological tests. No infected children were detected among the newborns of mothers treated before their pregnancy.

scholarly journals Comparison between the efficiency of serological tests for Identification of Brucellosis

2010 ◽  
Vol 7 (2) ◽  
pp. 901-909
Author(s):  
Baghdad Science Journal
Keyword(s):  
Rose Bengal ◽  
Serological Test ◽  
Elisa Test ◽  
Health Centers ◽  
Confirmatory Test ◽  
Igg Antibodies ◽  
Serological Tests ◽  
Primary Screening ◽  
Low Concentrations ◽  
Immune Assay

Five serological methods for detection of Brucella were compaired in this study, Four of the methods are commonely used in the detections:- 1-Rose-Bengal: as primary screening test which depends on detecting antibodies in the blood serum. 2-IFAT: which detects IgG and IgM antibodies in the serum. 3-ELISA test: which detects IgG antibodies in the serum. 4-2ME test: which detects IgG antibodies The fifth methods. It was developed by a reasercher in one of the health centers in Baghdad. It was given the name of spot Immune Assay (SIA). Results declares that among (100) samples of patients blood, 76, 49, 49, 37, and 28. samples were positive to Rose Bengal, ELISA, SIA, 2ME and IFAT tests, respectively. When efficiency, sensitivity and specificity of the serological methods were compaired, the Following results were obtained: a) ELISA and SIA were superiors among the other confirming methods (2ME and IFAT) in detecting the highest cases (49 cases); 46 of them were from the (76) cases positive to Rose Bengal The confirmatory test 2ME was not efficient in detecting low concentrations of IgG antibodies when less than half (37) of the total positive cases (76) were detected by this test. b) IFAT test was the least efficient confirmatory test among all other test. c) As a new confirmatory test, SIA proved to be an efficient and serological test for Brucella detection in comparison with other tests. It is an easy to use test, rapid and could be performed without need to the expensive equipment .

scholarly journals The Light and Shadow of Rapid Serological Tests for SARS-CoV-2 Infection: Results from a Study in a Large Emergency Department

2020 ◽  
Vol 17 (18) ◽  
pp. 6493
Author(s):  
Daniela Loconsole ◽  
Francesca Centrone ◽  
Caterina Morcavallo ◽  
Silvia Campanella ◽  
Anna Sallustio ◽  
...  
Keyword(s):  
Emergency Department ◽  
Real Time ◽  
Real Time Pcr ◽  
Respiratory Symptoms ◽  
Large Scale ◽  
Serological Test ◽  
Serological Tests ◽  
Serological Assay ◽  
Infected People ◽  
Screening Programs

A critical point in the management of the SARS-CoV-2 pandemic is the need to promptly identify the greatest number of infected people and to implement strict public health measures. In this study, the performance of a rapid serological test in a clinical setting was evaluated. Samples from 819 consecutive patients (with or without respiratory symptoms) admitted to a large Emergency Department were tested between 23 March and 21 April 2020. Patient samples were tested in a real-time PCR assay and a serological assay. In total, 148/819 patients (18.1%) tested positive for SARS-CoV-2 by real-time PCR. The serological test revealed that 70/819 patients (8.5%) had anti-SARS-CoV-2 IgM and/or IgG. The prevalence of anti-SARS-CoV-2 antibodies was significantly higher in patients with respiratory symptoms lasting for >7 days than in those with respiratory symptoms lasting for 0–7 days (p < 0.001). The serological assay had an overall sensitivity of 35.1% and an overall specificity of 97.3%. A high negative predictive value (96.7%) was reported for patients without respiratory symptoms. The results confirm that rapid serological assays alone are not sufficient for diagnosis of SARS-CoV-2 infection but can be incorporated into large-scale screening programs during periods in which the virus circulation is low.

scholarly journals The Trypomastigote Small Surface Antigen from Trypanosoma cruzi Improves Treatment Evaluation and Diagnosis in Pediatric Chagas Disease

2017 ◽  
Vol 55 (12) ◽  
pp. 3444-3453 ◽  
Author(s):  
Virginia Balouz ◽  
Luciano J. Melli ◽  
Romina Volcovich ◽  
Guillermo Moscatelli ◽  
Samanta Moroni ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Surface Antigen ◽  
Rapid Assessment ◽  
Drug Efficacy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Tests ◽  
Small Surface ◽  
Content Type

ABSTRACTChagas disease is caused by the protozoan parasiteTrypanosoma cruzi. Assessment of parasitological cure upon treatment with available drugs relies on achieving consistent negative results in conventional parasitological and serological tests, which may take years to assess. Here, we evaluated the use of a recombinantT. cruziantigen termed trypomastigote small surface antigen (TSSA) as an early serological marker of drug efficacy inT. cruzi-infected children. A cohort of 78 pediatric patients born toT. cruzi-infected mothers was included in this study. Only 39 of the children were infected withT. cruzi, and they were immediately treated with trypanocidal drugs. Serological responses against TSSA were evaluated in infected and noninfected populations during the follow-up period using an in-house enzyme-linked immunosorbent assay (ELISA) and compared to conventional serological methods. Anti-TSSA antibody titers decreased significantly faster than anti-whole parasite antibodies detected by conventional serology both inT. cruzi-infected patients undergoing effective treatment and in those not infected. The differential kinetics allowed a significant reduction in the required follow-up periods to evaluate therapeutic responses or to rule out maternal-fetal transmission. Finally, we present the case of a congenitally infected patient with an atypical course in whom TSSA provided an early marker forT. cruziinfection. In conclusion, we showed that TSSA was efficacious both for rapid assessment of treatment efficiency and for early negative diagnosis in infants at risk of congenitalT. cruziinfection. Based upon these findings we propose the inclusion of TSSA for refining the posttherapeutic cure criterion and other diagnostic needs in pediatric Chagas disease.

scholarly journals Genetic diversity of Trypanosoma cruzi parasites infecting dogs in southern Louisiana sheds light on parasite transmission cycles and serological diagnostic performance

2020 ◽  
Vol 14 (12) ◽  
pp. e0008932
Author(s):  
Eric Dumonteil ◽  
Ardem Elmayan ◽  
Alicia Majeau ◽  
Weihong Tu ◽  
Brandy Duhon ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Trypanosoma Cruzi ◽  
Test Performance ◽  
Serological Test ◽  
Parasite Transmission ◽  
Parasite Diversity ◽  
Serological Tests ◽  
Transmission Cycle ◽  
Southern Us ◽  
Transmission Cycles

Background Chagas disease is a neglected zoonosis of growing concern in the southern US, caused by the parasite Trypanosoma cruzi. We genotyped parasites in a large cohort of PCR positive dogs to shed light on parasite transmission cycles and assess potential relationships between parasite diversity and serological test performance. Methodology/principal findings We used a metabarcoding approach based on deep sequencing of T. cruzi mini-exon marker to assess parasite diversity. Phylogenetic analysis of 178 sequences from 40 dogs confirmed the presence of T. cruzi discrete typing unit (DTU) TcI and TcIV, as well as TcII, TcV and TcVI for the first time in US dogs. Infections with multiple DTUs occurred in 38% of the dogs. These data indicate a greater genetic diversity of T. cruzi than previously detected in the US. Comparison of T. cruzi sequence diversity indicated that highly similar T. cruzi strains from these DTUs circulate in hosts and vectors in Louisiana, indicating that they are involved in a shared T. cruzi parasite transmission cycle. However, TcIV and TcV were sampled more frequently in vectors, while TcII and TcVI were sampled more frequently in dogs. Conclusions/significance These observations point to ecological host-fitting being a dominant mechanism involved in the diversification of T. cruzi-host associations. Dogs with negative, discordant or confirmed positive T. cruzi serology harbored TcI parasites with different mini-exon sequences, which strongly supports the hypothesis that parasite genetic diversity is a key factor affecting serological test performance. Thus, the identification of conserved parasite antigens should be a high priority for the improvement of current serological tests.

Chemiluminescent Microparticle Immunoassay for the Diagnosis of Congenital Chagas Disease: A Prospective Study in Spain

2021 ◽  
Author(s):  
Luis Gil-Gallardo ◽  
Marina Simón ◽  
María Iborra ◽  
Bartolomé Carrilero ◽  
Manuel Segovia
Keyword(s):  
Prospective Study ◽  
Chagas Disease ◽  
Latin American ◽  
Serological Test ◽  
Serological Tests ◽  
Chemiluminescent Microparticle Immunoassay ◽  
A Prospective Study ◽  
Global Health Problem ◽  
Rule Out

Congenital Chagas disease (CCD) has become a global health problem. Historically, the diagnosis of CCD has been carried out using parasitological methods and traditional serological techniques, however, new serological techniques such as chemiluminescent microparticle immunoassays (CMIA) have been developed in the last few years with many advantages compared with traditional serological tests. A total of 75 children born to 72 Latin American Chagas-infected mothers were consecutively enrolled and studied by CMIA and indirect immunofluorescence (IIF) at 0–2, 6, 9, and 12 months of age. At the end of the follow-up, 74 out of 75 children were considered uninfected and one child was diagnosed with CCD. Our study emphasizes the need to carry out serological follow-up on every newborn from a mother with Chagas disease and shows that CMIA assay is a great diagnostic tool as a single serological test at 9 months of age to rule out CCD or to identify possible transmission.

scholarly journals Accurate Serodetection of Asymptomatic Leishmania donovani Infection by Use of Defined Antigens

2016 ◽  
Vol 54 (4) ◽  
pp. 1025-1030 ◽  
Author(s):  
Aarthy C. Vallur ◽  
Caroline Reinhart ◽  
Raodoh Mohamath ◽  
Yasuyuki Goto ◽  
Prakash Ghosh ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Leishmania Donovani ◽  
Serological Test ◽  
Unmet Need ◽  
Cost Effective ◽  
Asymptomatic Infection ◽  
Serological Tests ◽  
Content Type ◽  
Novel Proteins ◽  
Surveillance Programs

Infection withLeishmania donovaniis typically asymptomatic, but a significant number of individuals may progress to visceral leishmaniasis (VL), a deadly disease that threatens 200 million people in areas where it is endemic. While diagnosis of acute VL has been simplified by the use of cost-effective confirmatory serological tests, similar standardized tools are not widely available for detecting asymptomatic infection, which can be 4 to 20 times more prevalent than active disease. A simple and accurate serological test that is capable of detecting asymptomaticL. donovaniinfection will be useful for surveillance programs targeting VL control and elimination. To address this unmet need, we evaluated recombinant antigens for their ability to detect serum antibodies in 104 asymptomaticL. donovani-infected individuals (qualified as positive forL. donovani-specific antibodies by direct agglutination test [DAT]) from the Mymensingh district of Bangladesh where VL is hyperendemic. The novel proteins rKR95 and rTR18 possessed the greatest potential and detected 69% of DAT-positive individuals, with rKR95 being more robust in reactivity. Agreement in results for individuals with high DAT responses, who are more likely to progress to VL disease, was 74%. When considered along with rK39, a gold standard antigen that is used to confirm clinical diagnosis of VL but that is now becoming widely used for surveillance, rKR95 and rTR18 conferred a sensitivity of 84% based on a theoretical combined estimate. Our data indicate that incorporating rKR95 and rTR18 with rK39 in serological tests amenable to rapid or high-throughput screening may enable simple and accurate detection of asymptomatic infection. Such tests will be important tools to measureL. donovaniinfection rates, a primary goal in surveillance and a critical measurement with which to assess elimination programs.

scholarly journals Diagnostic-test evaluation of immunoassays for anti-Toxoplasma gondii IgG antibodies in a random sample of Mexican population

2014 ◽  
Vol 8 (05) ◽  
pp. 642-647 ◽  
Author(s):  
Heriberto Caballero-Ortega ◽  
Rocío Castillo-Cruz ◽  
Sandra Murieta ◽  
Luz Belinda Ortíz-Alegría ◽  
Esther Calderón-Segura ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Western Blot ◽  
Latin American ◽  
High Sensitivity ◽  
Reference Standards ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Serological Tests ◽  
Western Blots ◽  
Open Population

Introduction: There are few articles on evaluation of Toxoplasma gondii serological tests. Besides, commercially available tests are not always useful and are expensive for studies in open population. The aim of this study was to evaluate in-house ELISA and western blot for IgG antibodies in a representative sample of people living in Mexico. Methodology: Three hundred and five serum samples were randomly selected from two national seroepidemiological survey banks; they were taken from men and women of all ages and from all areas of the country. ELISA cut-off was established using the mean plus three standard deviations of negative samples. Western blots were analysed by two experienced technicians and positivity was established according to the presence of at least three diagnostic bands. A commercial ELISA kit was used as a third test. Two reference standards were built up: one using concordant results of two assays leaving the evaluated test out and the other in which the evaluated test was included (IN) with at least two concordant results to define diagnosis. Results: the lowest values of diagnostic parameters were obtained with the OUT reference standards: in-house ELISA had 96.9% sensitivity, 62.1% specificity, 49.6% PPV, 98.1% NPV and 71.8% accuracy, while western blot presented 81.8%, 89.7%, 84.0%, 88.2% and 86.6% values and the best kappa coefficient (0.72-0.82). Conclusions: The in-house ELISA is useful for screening people of Mexico, due to its high sensitivity, while western blot may be used to confirm diagnosis. These techniques might prove useful in other Latin American countries.

scholarly journals Dried Blood as an Alternative to Plasma or Serum for Trypanosoma cruzi IgG Detection in Screening Programs

2013 ◽  
Vol 20 (8) ◽  
pp. 1197-1202 ◽  
Author(s):  
Africa Holguín ◽  
Francesca Norman ◽  
Leticia Martín ◽  
María Luisa Mateos ◽  
Jesús Chacón ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
False Negative ◽  
Reference Method ◽  
Relative Sensitivity ◽  
Dried Blood Spots ◽  
Antibody Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serological Screening ◽  
Content Type ◽  
Screening Programs

ABSTRACTTrypanosoma cruziserological screening is recommended for people potentially exposed to this parasite in countries whereTrypanosoma cruziis endemic and those where it is not endemic. Blood samples on filter paper may be a practical alternative to plasma/serum for antibody detection. Using the Architect Chagas assay, we detected the presence of IgG againstT. cruziin matched serum and dried blood spots (DBS) collected from 147 patients residing in Madrid, Spain, who had potential previous exposure toT. cruzi. The κ statistic for the DBS/serum proportion of agreement for the detection of antibodies againstT. cruziwas 0.803, considering an S/CO (assay result unit; chemiluminescent signal from the sample [S] divided by the mean chemiluminescent signal for the three calibrators used in the test [CO]) cutoff value of ≥1.00. The relative sensitivity of the Architect test using DBS increased from 95.2% to 98.8% when the cutoff was lowered from ≥1.00 to ≥0.88, while the relative specificity decreased from 84.1% to 71.6%. Overall, the median S/CO values for DBS were significantly lower than those for serum (2.6 versus 6.5;P< 0.001). Discrepancies that occurred with the use of DBS included 10 false positives (with low S/CO values in 9 cases [median, 2.13]) and 4 false negatives, with mean S/CO values of 0.905 (gray zone). Using DBS plus a highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) may be a simple and reliable method for detecting IgG againstT. cruziwhen blood sampling by venipuncture is not feasible. This method may also reduce the false-negative rates observed with some rapid diagnostic tests. The lower relative sensitivity compared to the reference method may be increased by lowering the optical density threshold.

scholarly journals New Scheme of Intermittent Benznidazole Administration in Patients Chronically Infected with Trypanosoma cruzi: Clinical, Parasitological, and Serological Assessment after Three Years of Follow-Up

2020 ◽  
Vol 64 (9) ◽  
Author(s):  
María Gabriela Álvarez ◽  
Juan Carlos Ramírez ◽  
Graciela Bertocchi ◽  
Marisa Fernández ◽  
Yolanda Hernández ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Nuclear Dna ◽  
Parasite Load ◽  
Serological Tests ◽  
Content Type ◽  
Monocyte Chemoattractant Protein 1 ◽  
Specific Antibodies ◽  
Intermittent Administration ◽  
Low Rate

ABSTRACT In a pilot study, we showed that the intermittent administration of benznidazole in chronic Chagas disease patients resulted in a low rate of treatment suspension and therapeutic failure, as assessed by quantitative PCR (qPCR) at the end of treatment. Here, a 3-year posttreatment follow-up study of the same cohort of patients is presented. The treatment scheme consisted of 12 doses of benznidazole at 5 mg/kg of body weight/day in two daily doses every 5 days. Parasite load, Trypanosoma cruzi-specific antibodies, and serum chemokine levels were measured prior to treatment and after a median follow-up of 36 months posttreatment by DNA minicircle kinetoplastid and nuclear DNA satellite sequence qPCR methods, conventional serological techniques, a Luminex-based assay with recombinant T. cruzi proteins, and a cytometric bead array. At the end of follow-up, 14 of 17 (82%) patients had negative qPCR findings, whereas three of 17 (18%) had detectable nonquantifiable findings by at least one of the qPCR techniques. A decline in parasite-specific antibodies at 12 months posttreatment was confirmed by conventional serological tests and the Luminex assays. Monocyte chemoattractant protein 1 levels increased after treatment, whereas monokine induced by gamma interferon levels decreased. New posttreatment electrocardiographic abnormalities were observed in only one patient who had cardiomyopathy prior to treatment. Together, these data strengthen our previous findings by showing that the intermittent administration of benznidazole results in a low rate of treatment suspension, with treatment efficacy comparable to that of a daily dose of 5 mg/kg for 60 days.

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