Diagnostic Accuracy and Applicability of a PCR System for the Detection of Schistosoma mansoni DNA in Human Urine Samples from an Endemic Area

Schistosomiasis caused by Schistosoma mansoni, one of the most neglected human parasitoses in Latin America and Africa, is routinely confirmed by microscopic visualization of eggs in stool. The main limitation of this diagnostic approach is its lack of sensitivity in detecting individual low worm burdens and consequently data on infection rates in low transmission settings are little reliable. According to the scientific literature, PCR assays are characterized by high sensitivity and specificity in detecting parasite DNA in biological samples. A simple and cost effective extraction method for DNA of Schistosoma mansoni from urine samples in combination with a conventional PCR assay was developed and applied in an endemic area. This urine based PCR system was tested for diagnostic accuracy among a population of a small village in an endemic area, comparing it to a reference test composed of three different parasitological techniques. The diagnostic parameters revealed a sensitivity of 100%, a specificity of 91.20%, positive and negative predictive values of 86.25% and 100%, respectively, and a test accuracy of 94.33%. Further statistical analysis showed a k index of 0.8806, indicating an excellent agreement between the reference test and the PCR system. Data obtained from the mouse model indicate the infection can be detected one week after cercariae penetration, opening a new perspective for early detection and patient management during this stage of the disease. The data indicate that this innovative PCR system provides a simple to handle and robust diagnostic tool for the detection of S. mansoni DNA from urine samples and a promising approach to overcome the diagnostic obstacles in low transmission settings. Furthermore the principals of this molecular technique, based on the examination of human urine samples may be useful for the diagnosis of other neglected tropical diseases that can be detected by trans-renal DNA

Geographical illustration of the study area situated in the locality of Pedra Preta, municipality of Montes Claros, state of Minas Gerais, Brazil.

<p>Geographical illustration of the study area situated in the locality of Pedra Preta, municipality of Montes Claros, state of Minas Gerais, Brazil.</p

Visualization of 12 PCR assays with silver stained 8% polyacrylamide gel, showing the expected <i>S. mansoni</i> 110 bp DNA fragment in positive urine samples.

<p>NC: negative control; L: 100 bp Ladder; PC: positive control; lines 2, 3, 4, 5, 6, and 7: <i>S. mansoni</i> positive urine samples; lines 1, 8, 9, and 10: <i>S. mansoni</i> negative urine samples.</p

Comparison of positive and negative results obtained by PCR in urine samples and the copro-parasitological reference test for the detection of <i>S. mansoni</i> infection.

<p>Comparison of positive and negative results obtained by PCR in urine samples and the copro-parasitological reference test for the detection of <i>S. mansoni</i> infection.</p

Distribution according to gender and age groups of the study population living in Pedra Preta, Minas Gerais, Brazil.

<p>Distribution according to gender and age groups of the study population living in Pedra Preta, Minas Gerais, Brazil.</p

Wolbachia detection in insects through LAMP: loop mediated isothermal amplification.

Submitted by Nuzia Santos ([email protected]) on 2015-03-04T12:24:02Z No. of bitstreams: 1 2014_091.pdf: 527173 bytes, checksum: 7ebda7bf2dfb4a364f6783f1c65871ca (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-03-04T12:24:10Z (GMT) No. of bitstreams: 1 2014_091.pdf: 527173 bytes, checksum: 7ebda7bf2dfb4a364f6783f1c65871ca (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2015-03-04T13:00:51Z (GMT) No. of bitstreams: 1 2014_091.pdf: 527173 bytes, checksum: 7ebda7bf2dfb4a364f6783f1c65871ca (MD5)Made available in DSpace on 2015-03-04T13:00:51Z (GMT). No. of bitstreams: 1 2014_091.pdf: 527173 bytes, checksum: 7ebda7bf2dfb4a364f6783f1c65871ca (MD5) Previous issue date: 2014Fundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrazilFundação Oswaldo Cruz. Centro de Pesquisas René Rachou. Belo Horizonte, MG, BrazilBACKGROUND: The bacterium Wolbachia is a promising agent for the biological control of vector-borne diseases as some strains have the ability to block the transmission of key human disease-causing pathogens. Fast, accurate and inexpensive methods of differentiating between infected and uninfected insects will be of critical importance as field-based trials of Wolbachia-based bio-control become increasingly common. FINDINGS: We have developed a specific and sensitive method of detecting Wolbachia based on the isothermal DNA amplification. This technique can be performed in an ordinary heat block without the need for gel-based visualisation, and is effective for a wide variety of insect hosts. CONCLUSION: Here we present the development of a rapid, highly sensitive and inexpensive method to detect Wolbachia in a variety of insect hosts, including key mosquito disease vectors

Evaluación del impacto de las acciones del Programa de Control de la Esquistosomiasis en el control de las geohelmintiasis en São João Evangelista, Minas Gerais, Brasil, entre 1997 y 2013

Submitted by Nuzia Santos ([email protected]) on 2018-06-29T13:31:51Z No. of bitstreams: 1 Avaliação do impacto das ações do Programa.pdf: 133296 bytes, checksum: 1fa995d7412a37a316e977f365a32893 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2018-06-29T13:38:19Z (GMT) No. of bitstreams: 1 Avaliação do impacto das ações do Programa.pdf: 133296 bytes, checksum: 1fa995d7412a37a316e977f365a32893 (MD5)Made available in DSpace on 2018-06-29T13:38:19Z (GMT). No. of bitstreams: 1 Avaliação do impacto das ações do Programa.pdf: 133296 bytes, checksum: 1fa995d7412a37a316e977f365a32893 (MD5) Previous issue date: 2017Universidade Vale do Rio Doce. Mestrado em Ciências Biológicas. Governador Valadares, MG, BrasilUniversidade Vale do Rio Doce. Mestrado em Gestão Integrada de Território. Governador Valadares, MG, Brasil. (in memoriam)Universidade Estadual Paulista. Departamento de Geografia. Presidente Prudente, SP, BrasilFundação Oswaldo Cruz. Instituto Evandro Chagas. Seção de Parasitologia. Ananindeua, PA, BrasilFundação Oswaldo Cruz. Instituto René Rachou. Grupo de Pesquisa em Entomologia Médica. Belo Horizonte, MG, BrasilINTRODUÇÃO: O Programa de Controle da Esquistossomose (PCE), no Brasil, baseado em inquéritos coproscópicos e tratamento dos infectados, já diminuiu o número de portadores de formas graves e as taxas de mortalidade. OBJETIVOS: Testar a hipótese de que os dados do Sistema de Informação do Programa de Controle da Esquistossomose (SISPCE), na esfera municipal, permitem avaliar as prevalências da esquistossomose e geo-helmintoses e também o impacto das ações do PCE no controle dessas parasitoses. MATERIAIS E MÉTODOS: Foram utilizados dados do SISPCE e da Vigilância Epidemiológica do município de São João Evangelista, estado de Minas Gerais, do Instituto Brasileiro de Geografia e Estatística e da Companhia de Saneamento de Minas Gerais, referentes aos anos de 1997 a 2013. Foram calculadas frequências simples absolutas e percentuais de prevalência das parasitoses, bem como o percentual de cobertura do tratamento. O teste de Mann-Whitney foi utilizado para comparação desses dados entre as zonas urbana e rural. RESULTADOS: No período do estudo, os percentuais de positividade para esquistossomose variaram de 0,7% a 19,2%; para Ascaris lumbricoides, de 2,1% a 29,2%; e para os ancilostomídeos, de 0% a 52,9%. Não foram encontradas diferenças significativas nas prevalências dessas parasitoses entre as áreas urbana e rural. Dentre as localidades rurais trabalhadas, os dados indicaram a diminuição das prevalências dos helmintos após a disponibilização de água tratada. CONCLUSÃO: Os dados apresentados neste estudo mostraram a eficácia do PCE no diagnóstico e no controle não apenas da esquistossomose, mas também para outros helmintos, sugerindo a sua utilização nas ações públicas de controle dessas parasitoses.INTRODUCTION: Schistosomiasis Control Program (SCP) in Brazil is based on coproscopic investigations and treatment of infected people, and has already reduced the number of patients with severe forms and mortality rates. OBJECTIVES: To test the hypothesis that data from Schistosomiasis Control Program Information System (SCPIS) at municipal level allow the assessment of schistosomiasis and geohelmintoses prevalences, as well as the impact of SCP actions on the control of these parasitoses. MATERIALS AND METHODS: Data from SCPIS and Epidemiological Surveillance were used for the Municipality of São João Evangelista, Minas Gerais State, from Instituto Brasileiro de Geografia e Estatística and Companhia de Saneamento de Minas Gerais between 1997 and 2013. Absolute frequencies and prevalence percentages of parasitoses were calculated as well as the percentage of treatment coverage. The Mann-Whitney test was used to compare these data between urban and rural areas. RESULTS: During the study period, the positivity percentages for schistosomiasis ranged from 0.7% to 19.2%; for Ascaris lumbricoides from 2.1% to 29.2%; and for hookworms from 0% to 52.9%. No significant differences were found in the prevalence of these parasitoses between urban and rural areas. Among the rural areas studied, data indicated a decrease in the prevalence of helminths after the provision of treated water. CONCLUSION: Data presented in this study showed the effectiveness SCP for the diagnosis and control not only of schistosomiasis, but also of other helminths, suggesting to use it in public actions of control of these parasitic infections

An overview of malaria transmission from the perspective of Amazon Anopheles vectors

In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence