Schistosomiasis – Updating Technologies and Diagnostic Approaches in Surveillance Strategies and Clinical Management

Schistosoma infection is a poverty-related parasitic infection, being the second most important neglected tropical disease in the world after malaria. Schistosomiasis is caused by five distinct Schistosoma species distributed in tropical and subtropical areas. But, imported cases can also be seen in non - endemic areas. Human populations acquire infection after exposure to contaminated water collections. Schistosoma infection falls on a large spectrum of clinical manifestations that ranges from absence of signs and symptoms to severe forms of disease. Although morbidity and mortality have been reduced along the years after use of mass drug administration (MDA) in endemic areas, large populations are still at risk of disability-related outcomes on daily basis. Recently, a great deal of debate has been done over two main issues in schistosomiasis management in endemic and non-endemic areas: how to accurately diagnosis Schistosoma infections pre and post-therapy in addition to assess morbidity level. Adoption of promising new diagnostic tools and development of new markers of disease progression might change the current scenario by improving schistosomiasis clinical management in both community and institutional settings

Prevalence of human cryptosporidiosis in the Americas: systematic review and meta-analysis

Cryptosporidiosis is a disease caused by the Cryptosporidium spp parasite. As some species of Cryptosporidium have a wide host spectrum, the characterization of the pathogen at the species or genotype level is of great importance to define the sources of infection for humans and the potential for public health. This study investigated the diversity of the genus Cryptosporidium spp. in humans from all over the American continent and observed whether the method used to search for the parasite influenced the prevalence found in the Americas. This systematic review was carried out using the Pubmed, Science direct, Lilacs, Scielo, and Scopus databases with publications from January 1, 2010, to December 31, 2020. For data synthesis, the PRISMA flowchart was used and for the meta-analysis we used the MetaXL program. Of the selected publications, 57, 9 and 16 belonged to the region of South, Central and North America, respectively. The prevalence found for South, Central, and North America was 7%, 7%, and 8%, respectively, when analyzing publications that used only the microscopy method. When we analyzed the publications that used immunological and molecular methods, we found prevalences of 10%, 9%, and 21% for South, Central, and North America, respectively. The C. hominis subtype IbA10G2 was the most reported in the American continent, followed by subtype IeA11G3T3 and, for C. parvum, subtype IIaA15G2RI was the most reported. In conclusion, Cryptosporidium spp. is present throughout the American continent and its prevalence is higher when immunological and/or molecular methods are used, in addition to direct microscopic examination

Avaliação de testes imunológicos para o diagnóstico da neurocisticercose

Introdução: O diagnóstico da neurocisticercose (NCC) deve ser feito pela associação de técnicas de imagem com métodos imunológicos sensíveis e específicos. Objetivos: Avaliar os métodos Elisa e Western blot (Wb), utilizando-se como antígeno extrato bruto salino da larva da Taenia solium, o Cysticercus cellulosae e Wb, empregando-se como antígeno cisticercos da Taenia crassiceps em amostras de soro, para o diagnóstico da NCC. Materiais e métodos: Foram avaliadas amostras de soro de 43 pacientes com diagnóstico de NCC: 21 por clínica, tomografia computadorizada de crânio (TC) e presença de anticorpos anticisticerco no líquido cefalorraquiano (LCR); 22 por clínica e TC e 229 pacientes com diferentes parasitoses. Para as análises desses materiais biológicos foram empregados os métodos Elisa, usando-se como antígeno C. cellulosae, e Wb, usando-se como antígeno C. cellulosae e Cysticercus longicollis. Resultados: O método Elisa utilizando C. cellulosae como antígeno apresentou especificidade de 95% e sensibilidade de 71%. O método Wb utilizando C. cellulosae ou C. longicollis como antígeno apresentou sensibilidade de 86% e especificidade de 99%. Conclusões: Os métodos imunológicos no LCR são importantes para a definição da NCC. Entretanto o método Elisa no soro ainda não é adequado pela sua baixa sensibilidade, mas o Wb apresentou alta especificidade e boa sensibilidade, podendo auxiliar no diagnóstico da NCC, possibilitando sugerir a existência de forma transicional da doença, não demonstrada pela TC.<br>Background: The diagnosis of neurocysticercosis (NCC) has been made by association of neuroimaging studies and use of sensitive and specific serological assays. Objectives: Evaluating Elisa and Western blot (Wb) tests using a crude extract of Cysticercus cellulosae (Taenia solium) as antigen and a Wb test using a glycoprotein of Cysticercus longicollis (Taenia crassiceps) as antigen for the diagnosis of NCC. Methods: Serum samples from 43 patients with NCC: 21patients presenting clinical manifestations, cerebral computed tomography findings compatible with cerebral lesions and high levels of anti-cysticercus antibodies in cerebrospinal fluid (CSF); 22 patients with clinical manifestations and cerebral computed tomography findings compatible with cerebral lesions and serum samples from 229 patients with other parasitic infections were tested by Elisa standardized with crude extract of C. cellulosae and Wb standardized with glicoprotein of C. cellulosae and C. longicollis. Results: The Elisa test using crude extract of C. cellulosae showed specificity of 95% and sensibility of 71%. Both tests using glycoproteins of either C. cellulosae or C. longicollis showed specificity of 99% and sensibility of 86%. Conclusions: The use of immunological techniques for antibodies detection in CSF was shown to be an important tool for NCC diagnosis. However, detection of antibodies in serum lacked sensibility when Elisa was evaluated. The Wb assay in serum samples was sensitive and specific and it can be helpful for the diagnosis of the transitional form of NCC frequently not detected by cerebral computed tomography

The Advances in Molecular and New Point-of-Care (POC) Diagnosis of Schistosomiasis Pre- and Post-praziquantel Use: In the Pursuit of More Reliable Approaches for Low Endemic and Non-endemic Areas

Like soil-transmitted helminth infections, schistosomiasis is an important neglected tropical disease (NTD) related to poverty with a major impact on public health in developing countries. Diagnosis of active infection is crucial for surveillance of controlled or post-elimination schistosomiasis areas. In addition, the use of conventional diagnostic tools in non-exposed populations (such as travelers) results in misdiagnoses in the prepatent period of infection. Also, the accuracy of standard tests applied in low-endemicity areas (LEAs) decreases after several rounds of treatment. We aimed to determine whether it would be necessary to replace schistosomiasis conventional diagnostic tests such as parasitological methods in LEAs. Also, we evaluate the use of new tools in non-endemic areas. Reliable, cheap and easy-to-use diagnostic tools are needed to respond to the demands of a new era of elimination and eradication of schistosomiasis. To this end, molecular diagnosis—including nucleic acid-based assays (loop-mediated isothermal amplification, polymerase chain reaction) and circulating cathodic and anodic antigen detection tests have become promising strategies. In this review, we attempt to address the use of alternative diagnostic tests for active infection detection and drug-monitoring after specific schistosomiasis treatment

Differential Diagnosis of Entamoeba spp. in Clinical Stool Samples Using SYBR Green Real-Time Polymerase Chain Reaction

Amoebiasis, a disease caused by Entamoeba histolytica, is usually diagnosed by microscopic examination, which does not differentiate the morphologically identical species of the E. histolytica/E. dispar complex. Furthermore, morphologically similar species such as Entamoeba hartmanni contribute to misidentification. Therefore, there is a need for more sensitive and specific methods. This study standardized a multiplex real-time PCR system for E. histolytica and E. dispar and a single real-time PCR for E. hartmanni. The multiplex protocol detected up to 0.0143 pg of E. histolytica DNA and 0.5156 pg of E. dispar DNA, and the average melting temperature ( ) was 73 ∘ C and 70 ∘ C, respectively. For E. hartmanni, the was 73 ∘ C and the amplification was successful down to 0.03 fg of plasmid DNA. Negative controls and other intestinal parasites presented no amplification. Among the 48 samples tested, E. dispar DNA was detected in 37; none exhibited E. histolytica DNA and 11 were negative in the multiplex protocol. In 4 of these 11 samples, however, E. hartmanni DNA was amplified. SYBR Green is demonstrated to be an interesting option and these combined PCR reactions can improve laboratory diagnosis of amoebiasis in developing countries

Differential Diagnosis of Entamoeba

Amoebiasis, a disease caused by Entamoeba histolytica, is usually diagnosed by microscopic examination, which does not differentiate the morphologically identical species of the E. histolytica/E. dispar complex. Furthermore, morphologically similar species such as Entamoeba hartmanni contribute to misidentification. Therefore, there is a need for more sensitive and specific methods. This study standardized a multiplex real-time PCR system for E. histolytica and E. dispar and a single real-time PCR for E. hartmanni. The multiplex protocol detected up to 0.0143 pg of E. histolytica DNA and 0.5156 pg of E. dispar DNA, and the average melting temperature (Tm) was 73°C and 70°C, respectively. For E. hartmanni, the Tm was 73°C and the amplification was successful down to 0.03 fg of plasmid DNA. Negative controls and other intestinal parasites presented no amplification. Among the 48 samples tested, E. dispar DNA was detected in 37; none exhibited E. histolytica DNA and 11 were negative in the multiplex protocol. In 4 of these 11 samples, however, E. hartmanni DNA was amplified. SYBR Green is demonstrated to be an interesting option and these combined PCR reactions can improve laboratory diagnosis of amoebiasis in developing countries

Sobre el diseño y construcción de un túnel de viento supersónico bidimensional

Se ha diseñado, construido y ensayado satisfactoriamente un túnel de viento supersónico tipo Indraft bidimensional destinado al Laboratorio de Aeronáutica de la Facultad de Ciencias Exactas, Físicas y Naturales de la Universidad Nacional de Córdoba. Su propósito es visualizar los efectos de la compresibilidad en torno de un objeto que se desplaza dentro de una corriente supersónica. Para el cálculo de la geometría divergente de la tobera supersónica se ha empleado el método de las características, y para la visualización de las discontinuidades se utilizó la técnica Schlieren. Dentro de los logros más importantes se destacan el usto de la teoría de características para el diseño de la tobera, la incorporación de soportes que permiten intercambiar distintos modelos y el uso de ventanas laterales transparentes para el uso de la técnica Schlieren. Como resultado principales se consiguieron fotografías de ondas de choque oblicuas en torno a cuñas bidimensionales con ángulos de apertura de 10o , 20o y 30o , también se observó con un modelo escalón la onda de choque despegada. Además de las visualizaciones, se hicieron mediciones de presiones estáticas sobre las paredes de la tobera, las cuales fueron contrastadas con el perfil de presiones obtenido mediante simulaciones numéricas con OpenFOAM.A two-dimensional Indraft type supersonic wind tunnel was designed, built and successfully tested for the Aeronautics Laboratory of the Faculty of Exact, Physical and Natural Sciences of the National University of Córdoba, to visualize the effects of compressibility around an object that moves within a supersonic stream. The characteristics method was used to design the divergent geometry of the nozzle and a Schlieren visualization system was developed to visualize the shock waves. Among the most important achievements is the symmetrical geometry of the nozzle, the incorporation of supports that allow exchanging different models and the use of glass side windows for Schlieren use. Photographs of oblique shock waves around bidimensional wedges with 10o , 20o and 30o opening angles were obtained, as well as a detached shock wave was observed testing a blunt model. Measurements of static pressures were made along the tunnel which were contrasted with the pressures profile obtained by numerical simulations using OpenFOAM software.Fil: Dagaro, Mauro A.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: Peralta, Leonardo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: Ludueña, Guillermo Andres. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Lorenzon, Denis. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; ArgentinaFil: García, Jorge Osvaldo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; ArgentinaFil: Galeasso, Angel Andrés. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Bustamante, José. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Aeronáutica; Argentin

Aspectos clínicos e diagnósticos da microsporidiose intestinal em pacientes com infecção pelo HIV e diarréia crônica, no Rio de Janeiro, Brasil

The objectives of this study were to determine both the prevalence of microsporidial intestinal infection and the clinical outcome of the disease in a cohort of 40 HIV-infected patients presenting with chronic diarrhea in Rio de Janeiro, Brazil. Each patient, after clinical evaluation, had stools and intestinal fragments examined for viral, bacterial and parasitic pathogens. Microsporidia were found in 11 patients (27.5%) either in stools or in duodenal or ileal biopsies. Microsporidial spores were found more frequently in stools than in biopsy fragments. Samples examined using transmission electron microscopy (n=3) or polymerase chain reaction (n=6) confirmed Enterocytozoon bieneusi as the causative agent. Microsporidia were the only potential enteric pathogens found in 5 of the 11 patients. Other pathogens were also detected in the intestinal tract of 21 patients, but diarrhea remained unexplained in 8. We concluded that microsporidial infection is frequently found in HIV infected persons in Rio de Janeiro, and it seems to be a marker of advanced stage of AIDS.Os objetivos deste estudo foram determinar a prevalência e o prognóstico clínico da infecção por microsporídios em uma coorte de 40 pacientes com infecção pelo HIV e diarréia crônica na cidade do Rio de Janeiro, Brasil. Cada paciente teve suas fezes e fragmentos de intestino examinados para a pesquisa de CMV, bactérias e parasitos. A prevalência de microsporidiose foi de 27,5% (n=11). Esporos de microsporídios foram encontrados com maior frequência no exame direto das fezes do que em biópsias de intestino delgado. A microscopia eletrônica de transmissão e a reação de polimerase em cadeia (PCR) identificaram Enterocytozoon bieneusi, respectivamente, em 3 e 6 amostras examinadas, confirmando a espécie como único agente causal. Nenhum outro microrganismo patogênico, além dos microsporídios, foi detectada em 5 dos pacientes com diarréia. Outros parasitos foram encontrados no trato digestivo de 21 pacientes, enquanto que em 8 a etiologia da diarréia não foi definida. Concluímos que a infecção por microsporídios pode ser freqüentemente encontrada em indivíduos infectados pelo HIV no Rio de Janeiro