Unilateral hemi-central retinal artery occlusion as a presenting sign of Susac syndrome

ABSTRACT A young woman presented at our clinic with sudden visual loss in the right eye, recurrent vertigo, and right-sided tinnitus. We performed a complete ophthalmological evaluation. This revealed effects of the condition on the small arterioles of the peripheral retina. Susac syndrome is characterized by the clinical triad of retinal arteriolar occlusions, cochleovestibular manifestations, and encephalopathy (which can be identified by neuroimaging abnormalities). Early diagnosis and immunosuppressive therapy improved the patient's visual acuity and the remission of her other symptoms. Hemi-central retinal artery occlusion is an atypical neuro-ophthalmological finding in this disease. However, its identification as a sign of Susac syndrome may facilitate timely diagnosis and accurate treatment.

Los estudios por imágenes en la evaluación del niño con estridor / Imaging studies in evaluating children with stridor

El estridor es un síntoma de obstrucción de la vía aérea superior y puede ser resultado de causas congénitas o adquiridas. El diagnóstico suele ser clínico. Si es necesaria una investigación adicional para el diagnóstico diferencial, la endoscopia es el método de elección en la mayoría de los casos. Los estudios por imágenes son complementarios a la endoscopia. Permiten evaluar la patología laríngea y traqueobronquial, las compresiones extrínsecas de la vía aérea por tumores o malformaciones vasculares y definir la localización, extensión y características de una lesión. Son útiles en casos de duda diagnóstica y cuando la endoscopia no está disponible. Es fundamental comprender la anatomía y fisiopatología del tracto respiratorio, y ser conscientes de las indicaciones y limitaciones de los exámenes complementarios para el diagnóstico adecuado. Se describen las diferentes modalidades de imágenes disponibles para evaluar el estridor en pediatría y se discuten sus ventajas.

Stridor is a symptom of upper airway obstruction and may result from congenital or acquired causes. The diagnosis is usually clinical. If further investigation is necessary for differential diagnosis, endoscopy is the method of choice in most cases. Imaging studies are complementary to endoscopy. They allow evaluation of laryngeal and tracheobronchial pathology and extrinsic airway compressions due to tumors or vascular malformations and define a lesion's location, extent, and characteristics. They are helpful in cases of diagnostic doubt and when endoscopy is unavailable. It is essential to understand the anatomy and pathophysiology of the respiratory tract and to be aware of the indications and limitations of complementary examinations for proper diagnosis. The different imaging modalities available to evaluate stridor in pediatrics are described, and their advantages are discussed.

Estimated glomerular filtration rate in clinical practice: Consensus positioning of the Brazilian Society of Nephrology (SBN) and Brazilian Society of Clinical Pathology and Laboratory Medicine (SBPC/ML) / Estimativa da taxa de filtração glomerular na prática clínica: posicionamento consensual da Sociedade Brasileira de Nefrologia (SBN) e Sociedade Brasileira de Patologia Clínica e Medicina Laboratorial (SBPC/ML)

ABSTRACT Chronic kidney disease (CKD) represents one of today's main public health problems. Serum creatinine measurement and estimation of the glomerular filtration rate (GFR) are the main tools for evaluating renal function. There are several equations to estimate GFR, and CKD-EPI equation (Chronic Kidney Disease - Epidemiology) is the most recommended one. There are still some controversies regarding serum creatinine measurement and GFR estimation, since several factors can interfere in this process. An important recent change was the removal of the correction for race from the equations for estimating GFR, which overestimated kidney function, and consequently delayed the implementation of treatments such as dialysis and kidney transplantation. In this consensus document from the Brazilian Societies of Nephrology and Clinical Pathology and Laboratory Medicine, the main concepts related to the assessment of renal function are reviewed, as well as possible existing controversies and recommendations for estimating GFR in clinical practice.

RESUMO A doença renal crônica (DRC) representa um dos principais problemas de saúde pública da atualidade. A dosagem da creatinina sérica e a estimativa da taxa de filtração glomerular (TFG) são as principais ferramentas para avaliação da função renal. Para a estimativa da TFG, existem diversas equações, sendo a mais recomendada a CKD-EPI (Chronic Kidney Disease - Epidemiology). Existem ainda algumas controvérsias com relação à dosagem da creatinina sérica e da estimativa da TFG, uma vez que vários fatores podem interferir nesse processo. Uma importante mudança recente foi a retirada da correção por raça das equações para estimativa da TFG, que superestimavam a função renal, e consequentemente retardavam a implementação de tratamentos como diálise e transplante renal. Neste documento de consenso da Sociedade Brasileira de Nefrologia e Sociedade Brasileira de Patologia Clínica e Medicina Laboratorial são revisados os principais conceitos relacionados à avaliação da função renal, possíveis controvérsias existentes e recomendações para a estimativa da TFG na prática clínica.

Diagnóstico de tuberculosis en pediatría / Diagnosis of tuberculosis in pediatrics

La tuberculosis sigue siendo una epidemia mundial y en Chile no ha mostrado una tendencia descendente en los últimos años, con un aumento en los casos infantiles. En los niños, el diagnóstico es un reto debido a la baja carga bacilar y las características de las lesiones, que suelen ser cerradas. Métodos tradicionales como los cultivos, considerados anteriormente como el gold standard, con frecuencia arrojan resultados negativos. Sin embargo, los avances en pruebas moleculares han permitido un progreso significativo en la confirmación bacteriológica. Otras herramientas diagnósticas, como la prueba de tuberculina (PPD) y los ensayos de liberación de interferón gamma (IGRAs), tienen sensibilidades y especificidades variables, siendo útiles como pruebas complementarias. Las imágenes juegan un papel clave en la evaluación diagnóstica de tuberculosis pulmonar y extrapulmonar en pacientes pediátricos. Esta revisión aborda la epidemiología y el proceso diagnóstico de la tuberculosis infantil.

Tuberculosis remains a global epidemic, and in Chile, it has not shown a downward trend in recent years, with an increase in pediatric cases. Diagnosing tuberculosis in children presents challenges due to the low bacillary load and the closed nature of the lesions. Traditional methods like cultures, once considered the gold standard, often yield negative results. However, advances in molecular testing have significantly improved bacteriological confirmation. Other diagnostic tools, such as the tuberculin skin test (PPD) and interferon-gamma release assays (IGRAs), offer variable sensitivities and specificities and are useful as complementary tests. Imaging plays a critical role in the diagnostic evaluation of pulmonary and extrapulmonary tuberculosis in pediatric patients. This review addresses the epidemiology and diagnostic process of pediatric tuberculosis.

Diagnostic accuracy of an uncorrected native T1 mapping sequence for liver fibrosis and inflammation in autoimmune hepatitis: a prospective study using histopathology as reference standard.

PURPOSE: There is an unmet clinical need for non-invasive imaging biomarkers that could replace liver biopsy in the management of patients with autoimmune hepatitis (AIH). In this study, we sought to evaluate the diagnostic accuracy of a simple uncorrected, non-contrast T1 mapping for detecting fibrosis and inflammation in AIH patients using histopathology as a reference standard. MATERIAL AND METHODS: Over 3 years, 33 patients with AIH were prospectively studied using a multiparametric liver MRI protocol which included T1 mapping. Biopsies were performed up to 3 months before imaging, and a standardized histopathological score for fibrosis (F0-F4) and inflammatory activity (PPA0-4) was used as a reference. Statistical analysis included independent t test, Mann-Whitney U-test, and ROC (receiver operating characteristic) analysis. RESULTS: T1 mapping values were significantly higher in patients with advanced fibrosis (F0-2 vs. F3-4; p < 0.015), significant fibrosis (F0-1 vs. F2-4; p < 0.005), and significant inflammatory activity (PPA 0-1 vs. PPA 2-4 p = 0.048). Moreover, the technique demonstrated a good diagnostic performance in detecting significant (AUC 0.856) and advanced fibrosis (AUC 0.835), as well as significant inflammatory activity (AUC 0.763). CONCLUSION: A rapid, simple, uncorrected, non-contrast T1 mapping sequence showed satisfactory diagnostic performance in comparison with histopathology for detecting significant tissue inflammation and fibrosis in AIH patients, being a potential non-invasive imaging biomarker for monitoring disease activity in such individuals.

Development of a new accurate lateral flow immunoassay for diagnosis of human leptospirosis.

PURPOSE: The current diagnostic methods for leptospirosis diagnosis are technically complex and expensive, with limited applicability to specialized laboratories. Furthermore, they lack diagnostic accuracy in the acute stage of the disease, which coincides with a period when antibiotics are highly effective. New simple and accurate tests are mandatory to decentralize and improve diagnosis. Here, we introduced a new lateral flow immunoassay (Lepto-LF) for human leptospirosis. METHODS: We conducted a double-blinded assay using 104 serum samples from patients with confirmed or discarded diagnosis for leptospirosis. The diagnostic performance of Lepto-LF was estimated across different ranges of days from onset of symptoms (dpo), considering the diagnostic algorithm as reference standard. Additionally, it was compared with the screening methods enzyme-linked immunosorbent assay (IgM-ELISA) and the slide agglutination test using temperature-resistant antigen (SATR). RESULTS: Lepto-LF exhibited perfect diagnostic performance with a Youden´s index J = 1 from 6 dpo in the acute phase. IgM-ELISA gave slightly lower accuracy with J = 0.91 and 95.5% of both sensitivity and specificity; while SATR showed a markedly inferior yield (J = 0.41, sensitivity = 95.5%, specificity = 45.5%). The performances remained consistent in the convalescence phase of the disease (> 10 dpo). CONCLUSION: Lepto-LF was found to be a reliable test for simple, rapid and early diagnosis of leptospirosis, resulting a promising tool for decentralizing leptospirosis diagnosis and enabling timely treatment of patients. In addition, Lepto-LF may be employed as confirmatory test, especially in remote areas and vulnerable contexts where the standard MAT is not available.

[BIRADS 0 patient reclassification in a first-level of care unit]. / Reclasificación de pacientes BIRADS 0 en una unidad de primer nivel de atención.

Background: In Mexico and the world, breast cancer is the cancer type with the highest incidence and mortality for women. Its incidence has increased due to a higher life expectancy and a higher exposure to risk factors. Screening is done by mammography using the BIRADS (Breast Imaging Reporting and Data System) system, the standard for mammography screening report which classifies lesions assigning recommendations for patient follow-up. The system goes from 0 (not conclusive) to 6 (demonstrated malignancy), being of interest for this study the BIRADS 0 category. Objective: To describe patients classified as BIRADS 0 by mammography and their reclassification in a first-level hospital during 2021. Material and methods: Retrospective, descriptive, cross-sectional, observational study. Women over 40 years with a BIRADS 0 result were studied. The following databases were used: Institutional Cancer Registry, Family Medicine Information System, Electronic Clinical File, and the mammography and patient list from preventive medicine. Results: Reclassification by ultrasound (US) was achieved in 100% of patients, in all of the BIRADS US categories. In 3.8% of BIRADS 0 patients, ductal adenocarcinoma was found and confirmed by histological testing. Conclusion: All of the reassessed lesions with US were adequately reclassified.

Introducción: en México y el mundo, el cáncer de mama causa la mayor mortalidad por cáncer en mujeres. Su incidencia ha incrementado por una mayor esperanza de vida y exposición a factores de riesgo. El tamizaje de esta enfermedad se hace mediante mastografía, y para la estratificación de las lesiones se utiliza el sistema BIRADS (Breast Imaging Reporting and Data System), que estandariza el informe, categoriza las lesiones según el grado de sospecha y asigna recomendaciones a seguir. Dicho sistema va desde 0 (no concluyente) hasta 6 (lesión con malignidad demostrada) y es de interés para este estudio la categoría 0. Objetivo: describir la reclasificación de pacientes con reporte BIRADS 0 por mastografía durante 2021 en una unidad de primer nivel de atención. Material y métodos: estudio retrospectivo, descriptivo, transversal, observacional. Se estudiaron mujeres mayores de 40 años con resultado BIRADS 0. Se utilizaron las siguientes bases de datos: Registro Institucional de Cáncer, Sistema de Información de Medicina Familiar, Expediente Clínico Electrónico y lista nominal de mastografías y censo de pacientes sospechosos de medicina preventiva. Resultados: la reclasificación con ultrasonido (US) se logró en el 100% de pacientes, en todas las categorías de BIRADS US. En el 3.8% se confirmó carcinoma ductal por histología en las pacientes inicialmente categorizadas como BIRADS 0. Conclusiones: la totalidad de lesiones reevaluadas con US fueron reclasificadas satisfactoriamente.

Innovative imaging approaches for neuroendocrine tumor characterization: Combined dual energy CT and perfusion protocol implementation.

The article addresses the diagnostic value of the combined use of computed tomography (CT) perfusion and dual-energy CT (DECT) in patients with neuroendocrine tumors. It emphasizes the heterogeneity and complexity of these neoplasms, primarily affecting the gastrointestinal tract, bronchopulmonary system, and pancreas. While conventional CT is widely employed in their diagnosis, the combination of CT perfusion and dual-energy CT offers greater precision, particularly in detecting synchronous tumors and characterizing their vascularization. A clinical case of a patient with chronic abdominal symptoms, whose diagnosis was facilitated using both combined techniques, is presented. The discussion explores how CT perfusion assesses tumor vascularization and how dual-energy CT improves soft tissue differentiation, resulting in increased diagnostic accuracy. It is highlighted that this approach not only enhances detection rates but also positively impacts clinical management and healthcare costs. Therefore, the importance of considering these advanced tools in the diagnosis of neuroendocrine tumors to improve diagnostic precision and efficiency in patient care is underscored.

Características de la Diabetes del adulto de inicio juvenil y su diagnóstico en el laboratorio / Characteristics of Maturity Onset Diabetes of the Young and its diagnosis in the laboratory / Características do diabetes adulto de início juvenil e seu diagnóstico laboratorial

La Diabetes del adulto de inicio juvenil, es un subtipo hereditario poco común que se manifiesta a una edad temprana, relacionado con mutaciones en genes específicos que principalmente afectan la función de las células beta pancreática. Un diagnóstico preciso es fundamental para un tratamiento efectivo, aunque puede ser desafiante debido a la variabilidad en sus características clínicas y moleculares. Esta revisión analiza la evidencia disponible sobre estas características y los métodos de diagnóstico utilizados en laboratorio. Se realizó una búsqueda exhaustiva en bases de datos científicas, seleccionando estudios relevantes según criterios específicos. Se analizaron características clínicas, hallazgos moleculares y métodos de diagnóstico, utilizando tablas, gráficos y síntesis narrativas. Se identificaron mutaciones genéticas asociadas con MODY, así como biomarcadores útiles en el laboratorio clínico. Además, se describieron métodos de diagnóstico molecular, incluyendo la secuenciación de próxima generación (NGS). Esta revisión resalta la importancia del diagnóstico preciso de MODY, subrayando la diversidad de sus características biológicas y moleculares, y la necesidad de una investigación más profunda para mejorar su identificación y manejo clínico

Maturity Onset Diabetes of the Young is a rare hereditary subtype that manifests at an early age, related to mutations in specific genes that primarily affect the function of pancreatic beta cells. An accurate diagnosis is crucial for effective treatment, though it can be challenging due to variability in clinical and molecular characteristics. This review examines available evidence on these characteristics and laboratory diagnostic methods. A comprehensive search was conducted in scientific databases, selecting relevant studies based on specific criteria. Clinical features, molecular findings, and diagnostic methods were analyzed using tables, graphs, and narrative synthesis. Genetic mutations associated with MODY were identified, as well as useful biomarkers in clinical laboratory settings. Additionally, molecular diagnostic methods were described, including next-generation sequencing (NGS). This review emphasizes the importance of precise MODY diagnosis, highlighting the diversity of its biological and molecular characteristics, and the need for further research to enhance its identification and clinical management

A diabetes adulto de início juvenil é um subtipo hereditário raro que se manifesta em uma idade precoce, relacionado a mutações em genes específicos que afetam principalmente a função das células beta do pâncreas. Um diagnóstico preciso é fundamental para um tratamento eficaz, embora possa ser desafiador devido à variabilidade em suas características clínicas e moleculares. Esta revisão analisa a evidência disponível sobre essas características e os métodos de diagnóstico utilizados em laboratório. Foi realizada uma busca abrangente em bases de dados científicas, selecionando estudos relevantes com base em critérios específicos. Características clínicas, descobertas moleculares e métodos de diagnóstico foram analisados utilizando tabelas, gráficos e síntese narrativa. Foram identificadas mutações genéticas associadas ao MODY, assim como biomarcadores úteis em laboratório clínico. Além disso, foram descritos métodos de diagnóstico molecular, incluindo a sequenciação de próxima geração (NGS). Esta revisão enfatiza a importância do diagnóstico preciso do MODY, destacando a diversidade de suas características biológicas e moleculares e a necessidade de uma pesquisa mais aprofundada para melhorar sua identificação e manejo clínico

Características de la Diabetes del adulto de inicio juvenil y su diagnóstico en el laboratorio

La Diabetes del adulto de inicio juvenil, es un subtipo hereditario poco común que se manifiesta a una edad temprana, relacionado con mutaciones en genes específicos que principalmente afectan la función de las células beta pancreática. Un diagnóstico preciso es fundamental para un tratamiento efectivo, aunque puede ser desafiante debido a la variabilidad en sus características clínicas y moleculares. Esta revisión analiza la evidencia disponible sobre estas características y los métodos de diagnóstico utilizados en laboratorio. Se realizó una búsqueda exhaustiva en bases de datos científicas, seleccionando estudios relevantes según criterios específicos. Se analizaron características clínicas, hallazgos moleculares y métodos de diagnóstico, utilizando tablas, gráficos y síntesis narrativas. Se identificaron mutaciones genéticas asociadas con MODY, así como biomarcadores útiles en el laboratorio clínico. Además, se describieron métodos de diagnóstico molecular, incluyendo la secuenciación de próxima generación (NGS). Esta revisión resalta la importancia del diagnóstico preciso de MODY, subrayando la diversidad de sus características biológicas y moleculares, y la necesidad de una investigación más profunda para mejorar su identificación y manejo clínico.

Maturity Onset Diabetes of the Young is a rare hereditary subtype that manifests at an early age, related to mutations in specific genes that primarily affect the function of pancreatic beta cells. An accurate diagnosis is crucial for effective treatment, though it can be challenging due to variability in clinical and molecular characteristics. This review examines available evidence on these characteristics and laboratory diagnostic methods. A comprehensive search was conducted in scientific databases, selecting relevant studies based on specific criteria. Clinical features, molecular findings, and diagnostic methods were analyzed using tables, graphs, and narrative synthesis. Genetic mutations associated with MODY were identified, as well as useful biomarkers in clinical laboratory settings. Additionally, molecular diagnostic methods were described, including next-generation sequencing (NGS). This review emphasizes the importance of precise MODY diagnosis, highlighting the diversity of its biological and molecular characteristics, and the need for further research to enhance its identification and clinical management.

A diabetes adulto de início juvenil é um subtipo hereditário raro que se manifesta em uma idade precoce, relacionado a mutações em genes específicos que afetam principalmente a função das células beta do pâncreas. Um diagnóstico preciso é fundamental para um tratamento eficaz, embora possa ser desafiador devido à variabilidade em suas características clínicas e moleculares. Esta revisão analisa a evidência disponível sobre essas características e os métodos de diagnóstico utilizados em laboratório. Foi realizada uma busca abrangente em bases de dados científicas, selecionando estudos relevantes com base em critérios específicos. Características clínicas, descobertas moleculares e métodos de diagnóstico foram analisados utilizando tabelas, gráficos e síntese narrativa. Foram identificadas mutações genéticas associadas ao MODY, assim como biomarcadores úteis em laboratório clínico. Além disso, foram descritos métodos de diagnóstico molecular, incluindo a sequenciação de próxima geração (NGS). Esta revisão enfatiza a importância do diagnóstico preciso do MODY, destacando a diversidade de suas características biológicas e moleculares e a necessidade de uma pesquisa mais aprofundada para melhorar sua identificação e manejo clínico.

Cardiac disease discrimination from 3D-convolutional kinematic patterns on cine-MRI sequences. / Discriminación de enfermedades cardiacas utilizando patrones cinemáticos codificados con convoluciones 3D en secuencias de cine-RM

INTRODUCTION: Cine-MRI (cine-magnetic resonance imaging) sequences are a key diagnostic tool to visualize anatomical information, allowing experts to localize and determine suspicious pathologies. Nonetheless, such analysis remains subjective and prone to diagnosis errors. OBJECTIVE: To develop a binary and multi-class classification considering various cardiac conditions using a spatiotemporal model that highlights kinematic movements to characterize each disease. MATERIALS AND METHODS: This research focuses on a 3D convolutional representation to characterize cardiac kinematic patterns during the cardiac cycle, which may be associated with pathologies. The kinematic maps are obtained from the apparent velocity maps computed from a dense optical flow strategy. Then, a 3D convolutional scheme learns to differentiate pathologies from kinematic maps. RESULTS: The proposed strategy was validated with respect to the capability to discriminate among myocardial infarction, dilated cardiomyopathy, hypertrophic cardiomyopathy, abnormal right ventricle, and normal cardiac sequences. The proposed method achieves an average accuracy of 78.00% and a F1 score of 75.55%. Likewise, the approach achieved 92.31% accuracy for binary classification between pathologies and control cases. CONCLUSION: The proposed method can support the identification of kinematically abnormal patterns associated with a pathological condition. The resultant descriptor, learned from the 3D convolutional net, preserves detailed spatiotemporal correlations and could emerge as possible digital biomarkers of cardiac diseases.

Introducción. Las secuencias del cine-resonancia magnética (cine-MRI, cine magnetic resonance imaging) son una herramienta diagnóstica clave para visualizar la información anatómica que les permite a los expertos localizar y determinar aquellas anomalías que resulten sospechosas. No obstante, este análisis sigue siendo subjetivo y propenso a errores de diagnóstico. Objetivo. Desarrollar una clasificación binaria y multiclase, considerando diferentes condiciones cardiacas, mediante un modelo espaciotemporal que permita resaltar los movimientos cinéticos para caracterizar cada enfermedad. Materiales y métodos. Este estudio se centra en el uso de una representación de convolución 3D para caracterizar los patrones cinéticos durante el ciclo cardiaco que puedan estar asociados con enfermedades. Para ello, se obtienen mapas cinéticos a partir de mapas de velocidad aparente, calculados mediante una estrategia de flujo óptico denso. A continuación, un esquema de convolución 3D "aprende" a diferenciar patologías a partir de mapas cinemáticos. Resultados. La estrategia propuesta se validó según la capacidad de discriminar entre infarto de miocardio, miocardiopatía dilatada, miocardiopatía hipertrófica, ventrículo derecho anormal y un examen normal. El método propuesto alcanza una precisión media del 78,0 % y una puntuación F1 score del 75,55 %. Asimismo, el enfoque alcanzó el 92,31 % de precisión para la clasificación binaria entre enfermedades y casos de control. Conclusiones. El método propuesto es capaz de apoyar la identificación de patrones cinéticos anormales asociados con una condición patológica. El descriptor resultante, aprendido de la red de convolución 3D, conserva correlaciones espaciotemporales detalladas y podría surgir como posible biomarcador digital de enfermedades cardiacas.

Asymptomatic Malaria Reservoirs in Honduras: A Challenge for Elimination.

BACKGROUND: Efforts on a global scale for combating malaria have achieved substantial progress over the past twenty years. Two Central American nations have accomplished their goal of eliminating malaria: El Salvador and Belize. Honduras has decreased the incidence of malaria and now reports fewer than 4000 malaria cases annually, aspiring to reach elimination by 2030. To accomplish this goal, it is essential to assess the existing strategies employed for malaria control and to address the task of incorporating novel intervention strategies to identify asymptomatic reservoirs. METHODS: A survey for detecting asymptomatic cases was carried out in the community of Kaukira, in Gracias a Dios, Honduras, focusing on malaria transmission during 2023. Asymptomatic community members were recruited as participants, malaria screening was performed through a rapid diagnostic test in situ, and a blood sample was collected on filter paper. Highly sensitive molecular assays based on photo-induced electron transfer PCR (PET-PCR) were performed to detect the two species of Plasmodium circulating in Honduras: Plasmodium vivax and Plasmodium falciparum. In addition, the identification of the parasite species was verified by amplifying three genetic markers (Pvmsp3α, Pvmsp3ß, and Pfmsp1). RESULTS: A total of 138 participants were recruited, mostly adult women. All individuals tested negative on the rapid diagnostic test. Positive results for malaria were detected by PET-PCR in 17 samples (12.3%). Most samples (12 out of 17) were amplified with a Ct value between 37 and 42, indicating very low parasitemias. Out of the 17 samples, 16 of them also showed amplification in the species assays. There were nine cases of P. falciparum infections and seven cases of P. vivax infections that were further confirmed by nested PCR (nPCR) of Pvmsp3 and Pfmsp1. Parasitemias ranged from 100 p/µL to less than 0.25 p/µL. One sample showed mixed infection. CONCLUSIONS: The existence of asymptomatic malaria reservoirs in Honduras can contribute to disease transmission and pose a challenge that may hinder elimination efforts, requiring public health authorities to modify surveillance strategies to identify the disease and treat this population accordingly.

High Frequency of Deletions in the pfhrp2 and pfhrp3 Genes of Plasmodium falciparum in the Middle Rio Negro Region of the Brazilian Amazon.

Several countries are reporting natural populations of P. falciparum with deletions in the pfhrp2/3 genes that can lead to false-negative results in rapid diagnostic tests. To investigate the prevalence of deletion in the pfhrp2/3 genes in the Rio Negro basin in the Brazilian Amazon and identify whether there is clinical differentiation between individuals infected by these parasites, clinical samples collected from 2003 to 2016 were analyzed from symptomatic and asymptomatic P. falciparum-infected individuals. The molecular deletion of pfhrp2 and pfhrp3 genes was evaluated using the protocols recommended by the WHO. From 82 samples used, 28 (34.2%) had a single deletion in pfhrp2, 19 (23.2%) had a single deletion in pfhrp3, 15 (18.3%) had a double deletion (pfhrp2/3), and 20 (24.4%) did not have a deletion in either gene. In total, 29.3% of individuals had an asymptomatic plasmodial infection and were 3.64 times more likely to have parasites with a double deletion (pfhrp2/3) than patients with clinical malaria (p = 0.02). The high prevalence of parasites with pfhrp2/3 deletions shows the need to implement a surveillance program in this area. Deletions in parasites may be associated with the clinical pattern of the disease in this area. More studies must be carried out to elucidate these findings.

Experimental Granulomatous Amebic Encephalitis Caused by Acanthamoeba castellanii.

Acanthamoeba genus can affect humans with diseases such as granulomatous amebic encephalitis (GAE), a highly lethal neuroinfection. Several aspects of the disease still need to be elucidated. Animal models of GAE have advanced our knowledge of the disease. This work tested Wistar rats (Rattus norvegicus albinus) as an animal model of GAE. For this, 32 animals were infected with 1 × 106A. castellanii trophozoites of the T4 genotype. Ameba recovery tests were carried out using agar plates, vascular extravasation assays, behavioral tests, and histopathological technique with H/E staining. Data were subjected to linear regression analysis, one-way ANOVA, and Tukey's test, performed in the GraphPad Prism® 8.0 program, with a significance level of p < 0.05. The results revealed the efficiency of the model. Amebae were recovered from the liver, lungs, and brain of infected animals, and there were significant encephalic vascular extravasations and behavioral changes in these animals, but not in the control animals. However, not all infected animals showed positive histopathology for the analyzed organs. Nervous tissues were the least affected, demonstrating the role of the BBB in the defense of the CNS. Supported by the demonstrated evidence, we confirm the difficulties and the feasibilities of using rats as an animal model of GAE.

Cost-consequence analysis of a combined COVID-19/influenza rapid diagnostic test in the Brazilian private healthcare setting.

Combination COVID-19/influenza rapid tests provide a way to quickly and accurately differentiate between the two infections. The goal of this economic evaluation was to assess the cost and health benefits of a combination COVID-19/influenza Rapid Diagnostic Test (RDT) vs. current standard-of-care in the Brazilian private healthcare setting. A dual decision tree model was developed to estimate the impact of rapid differentiation of COVID-19 and influenza in a hypothetical cohort of 1,000 adults with influenza-like illness in an ambulatory healthcare setting. The model compared the use of a combination COVID-19/influenza RDT to Brazil standard diagnostic practice of a COVID-19 RDT and presumptive influenza diagnosis. Different levels of influenza prevalence were modeled with co-infection estimated as a function of the COVID-19 prevalence. Outcomes included accuracy of diagnosis, antiviral prescriptions and healthcare resource use (hospital bed days and ICU occupancy). Depending on influenza prevalence, considering 1,000 patients with influenza-like illness, a combination RDT compared to standard practice was estimated to result in between 88 and 149 fewer missed diagnoses of influenza (including co-infection), 161 to 185 fewer cases of over-diagnosis of influenza; a 24 to 34% reduction in hospital bed days and a 16 to 26% reduction in ICU days. In the base case scenario (20% influenza, 5% COVID-19), the combination RDT was estimated to result in cohort cost savings of $99. Based upon a de novo economic model, this analysis indicates that use of a combination RDT could positively impact influenza antiviral prescriptions and lower healthcare resource use.

Assessing the predictive capability of N, P, and B diagnosis in cotton crop.

The compositional nutrient diagnosis-CND method is a standard tool for evaluating plant nutritional status. Adjustments are crucial to elevate accuracy. The effectiveness of such methodological refinements should be rigorously assessed through accuracy tests that are benchmarked against the prescient diagnostic analysis-PDA methodology. The objective of this investigation was to refine the CND technique for a more precise evaluation of N, P, and B nutrient status in cotton. The study's database encompasses 144 data points pertaining to crop yield and foliar nutrient concentrations from cotton plantations in the Cerrado biome of Brazil. Subsequently, the CND norms were established through rigorous calibration. Three separate nutrient-dose trials, each featuring four levels of N, P and B, were carried out to assess plant true nutritional status. Adjustments were made to the nutrient responsiveness range-NRr (0.5 and 1.0), while yield response-YR were scrutinized at threshold levels (5% and 10%). The prerequisites for achieving high diagnostic accuracy were nutrient specific. For N, maximal accuracy was linked only to the YR parameter (YR = 10%). For P, the most precise outcomes were attained with a NRr = 0.5 and YI = 5%. For B, highest diagnostic accuracy when the NRr = 1.0 and YI = 10%. These insights highlight the need to fine-tune the CND method for reliable nutritional evaluations and cotton crop productivity optimization.

Diagnostic Accuracy of the Abbott BinaxNOW COVID-19 Antigen Card Test, Puerto Rico.

BACKGROUND: The COVID-19 pandemic underscored the need for rapid and accurate diagnostic tools. In August 2020, the Abbott BinaxNOW COVID-19 Antigen Card test became available as a timely and affordable alternative for SARS-CoV-2 molecular testing, but its performance may vary due to factors including timing and symptomatology. This study evaluates BinaxNOW diagnostic performance in diverse epidemiological contexts. METHODS: Using RT-PCR as reference, we assessed performance of the BinaxNOW COVID-19 test for SARS-CoV-2 detection in anterior nasal swabs from participants of two studies in Puerto Rico from December 2020 to May 2023. Test performance was assessed by days post symptom onset, collection strategy, vaccination status, symptomatology, repeated testing, and RT-PCR cycle threshold (Ct) values. RESULTS: BinaxNOW demonstrated an overall sensitivity of 84.1% and specificity of 98.8%. Sensitivity peaked within 1-6 days after symptom onset (93.2%) and was higher for symptomatic (86.3%) than asymptomatic (67.3%) participants. Sensitivity declined over the course of infection, dropping from 96.3% in the initial test to 48.4% in testing performed 7-14 days later. BinaxNOW showed 99.5% sensitivity in participants with low Ct values (≤ 25) but lower sensitivity (18.2%) for participants with higher Cts (36-40). CONCLUSIONS: BinaxNOW demonstrated high sensitivity and specificity, particularly in early-stage infections and symptomatic participants. In situations where test sensitivity is crucial for clinical decision-making, nucleic acid amplification tests are preferred. These findings highlight the importance of considering clinical and epidemiological context when interpreting test results and emphasize the need for ongoing research to adapt testing strategies to emerging SARS-CoV-2 variants.

Evaluation of concordance of new QuantiFERON-TB Gold Plus platforms for Mycobacterium tuberculosis infection diagnosis in a prospective cohort of household contacts.

Interferon-gamma (IFN-γ) release assays play a pivotal role in tuberculosis infection (TBI) diagnosis, with QuantiFERON-TB Gold Plus-an enzyme-linked immunosorbent assay (ELISA)-among the most widely utilized. Newer QuantiFERON-TB platforms with shorter turnaround times were recently released. We aimed to evaluate these platforms' agreement in the diagnosis of TBI. Blood samples from a prospective cohort of tuberculosis household contacts were collected at baseline and after 12 weeks of follow-up, and tested with LIAISON, an automated chemiluminescence immunoassay (CLIA) system, QIAreach, a lateral flow (QFT-LF) semi-automated immunoassay, and the ELISA QuantiFERON-TB Gold Plus platform. Test concordances were analyzed. ELISA vs CLIA overall agreement was 83.3% for all tested samples (120/144) [Cohen's kappa coefficient (κ): 0.66 (95% CI: 0.54-0.77)]. Samples positive with CLIA provided consistently higher IFN-γ levels than with ELISA (P < 0.001). Twenty-four (16.7%) discordant pairs were obtained, all CLIA-positive/ELISA-negative: 15 (62.5%) had CLIA IFN-γ levels within borderline values (0.35-0.99 IU/mL) and 9 (37.5%) >0.99 IU/mL. QFT-LF showed only 76.4% (68/89) overall agreement with ELISA [κ: 0.53 (95% CI: 0.37-0.68)] with 21 (23.6%) discordant results obtained, all QFT-LF-positive/ELISA-negative. Overall concordance between ELISA and CLIA platforms was substantial, and only moderate between ELISA and QFT-LF. The CLIA platform yielded higher IFN-γ levels than ELISA, leading to an almost 17% higher positivity rate. The techniques do not seem interchangeable, and validation against other gold standards, such as microbiologically-confirmed tuberculosis disease, is required to determine whether these cases represent true new infections or whether CLIA necessitates a higher cutoff. IMPORTANCE: Tuberculosis is an airborne infectious disease caused by Mycobacterium tuberculosis that affects over 10 million people annually, with over 2 billion people carrying an asymptomatic tuberculosis infection (TBI) worldwide. Currently, TBI diagnosis includes tuberculin skin test and the blood-based interferon-gamma (IFN-γ) release assays, with Qiagen QuantiFERON-TB Gold Plus (QFT) being among those most widely utilized. We evaluated Qiagen's newer QFT platforms commercially available in a prospective cohort of tuberculosis contacts. A substantial agreement was obtained between the current QFT-enzyme-linked immunosorbent assay (ELISA) and the new QFT-chemiluminescence immunoassay (CLIA) platform, although QFT-CLIA provided higher concentrations of IFN-γ, leading to a 16.6% higher positivity rate. We highlight that both platforms may not be directly interchangeable and that further validation is required.

Evaluation of nasal swab and nasal wipe for detection of Influenza A in swine using Bayesian latent class analysis.

Influenza A virus (IAV) is an important pathogen in Brazilian swine herds, and monitoring the viral circulation is essential to control and reduce the transmission. Surveillance programs for IAV are often based on individual piglets level sampling, making the evaluation of the available diagnostic tools crucial to assessing IAV circulation in herds. Thus, two sample collection methodologies were compared in pig herds in southern Brazil to detect IAV by RT-qPCR: nasal swab (NS) and nasal wipe (NW). A Bayesian latent class model (BLCM) was set for two tests and two populations. The NW and NS used are more specific (higher than 95 % for both) than sensitive. The sensitivity for NW was lower than the NS, 84.14 % (70 % - 95 %; posterior probability interval (PPI): 95 %) and 87.15 % (73 % - 97 %; PPI: 95 %), respectively, and the specificity was 95 % (90 % - 99 %; PPI: 95 %) and 99 % (96 % - 100 %; PPI: 95 %), respectively. Although the wipe sample collection loses both sensitivity and specificity compared with nasal swab, differences in test performance were very limited and PPIs largely overlapped. Therefore NW can also be considered a valuable tool. The decision about the use of both techniques should be based on the trade-off between their performance limitations and feasibility in routine monitoring.

Esophageal Mucosal Impedance Assessment for the Diagnosis of Gastroesophageal Reflux Disease.

Background/Aims: Diagnosing gastroesophageal reflux disease (GERD) is sometimes challenging because the performance of available tests is not entirely satisfactory. This study aims to directly measure the esophageal mucosal impedance during upper gastrointestinal endoscopy for the diagnosis of GERD. Methods: Sixty participants with typical symptoms of GERD underwent high-resolution esophageal manometry, 24-hour multichannel intraluminal impedance-pH monitoring, upper gastrointestinal endoscopy, and mucosal impedance measurement. Mucosal impedance measurement was performed at 2, 5, 10, and 18 cm above the esophagogastric junction during gastrointestinal endoscopy using a specific catheter developed based on devices described in the literature over the last decade. The patients were divided into groups A (acid exposure time < 4%) and B (acid exposure time ≥ 4%). Results: The mucosal impedance was significantly lower in group B at 2 cm (2264.4 Ω ± 1099.0 vs 4575.0 Ω ± 1407.6 [group A]) and 5 cm above the esophagogastric junction (4221.2 Ω ± 2623.7 vs 5888.2 Ω ± 2529.4 [group A]). There was no significant difference in the mucosal impedance between the 2 groups at 10 cm and 18 cm above the esophagogastric junction. Mucosal impedance value at 2 cm > 2970 Ω resulted in a sensitivity of 96.4% and a specificity of 87.5% to exclude GERD. Conclusions: Direct measurement of mucosal impedance during endoscopy is a simple and promising method for diagnosing GERD. Individuals with an abnormal acid exposure time have lower mucosal impedance measurements than those with a normal acid exposure time.