A Dye Uptake Assay to Measure Large-Pore Channel Activity in Trypanosoma cruzi.

Large-pore channels allow the exchange of ions and molecules between the intra- and extracellular compartments. These channels are structures formed by several protein families with little or no evolutionary linkages that include connexins (Cxs), pannexins (Panxs), innexins (Inxs), CALHM1, and LRRC8 proteins. Recently, we have described the unnexins (Unxs) proteins expressed in Trypanosoma cruzi (T. cruzi) that also is like to form large-pore channels at the plasma membrane. In this chapter, we describe a dye uptake method for evaluating the unnexin-formed channel function in T. cruzi, as well as the methods for evaluating their participation in the transformation of trypomastigotes into amastigotes. These methods can facilitate understanding the role of large-pore channels in the parasite's biology.

Biological activities of 1,4-naphthoquinones derivatives against T. cruzi and L. amazonensis

SUMMARY Introduction: Chagas disease and Leishmaniasis are neglected diseases caused by the Trypanosoma cruzi and kentoplastid parasites Leishmania spp. Parasitic diseases cause great impact on social and economic, affecting millions of people in the world and represent a major global health problem. In the search for new alternatives for the treatment of Leishmaniasis and Chagas disease, strategies have been used to discover new active molecules, because there is an urgent need for the development of new drugs. In this scenario, 1,4-naphthoquinones have shown notable activity in the context of neglected diseases. Aim: To synthesis of 1,4-naphthoquinones derivatives and evaluated these compounds against Trypanosoma cruzi epimastigotes, Leishmania promastigotes (Leishmania amazonensis) and cytotoxicity to LLCMK2 cells. Results: Nine 1,4-naphthoquinones derivatives were synthesized using 2-Bromo-1,4-naphthoquinone (1), 1,4-Naphthoquinone (5) and 2-Hydroxi-1,4-naphthoqui-none (9) as starting material. Derivative 6a exhibited excellent trypanocidal activity, IC50 of 0.25 ± 0.02 µM, superior potency compared with the reference drug Benznidazol. Besides, these compounds displayed low activity against promastigote from L. amazonensis. Conclusion: The results indicate that compound 6a may have potential for agent against Chagas disease.

Introducción: La enfermedad de Chagas y la leishmaniasis son enfermedades desatendidas causadas por los parásitos Trypanosoma cruzi y kentoplastid Leishmania spp. Las enfermedades parasitarias tienen un gran impacto social y económico, afectan a millones de personas en el mundo y representan un importante problema de salud mundial. En la búsqueda de nuevas alternativas para el tratamiento de la leishmaniasis y la enfermedad de Chagas, se han utilizado estrategias para descubrir nuevas moléculas activas, porque existe una necesidad urgente de desarrollo de nuevos fármacos. En este escenario, las 1,4-naftoquinonas han mostrado una notable actividad en el contexto de enfermedades desatendidas. Objetivo: Sintetizar derivados de 1,4-naftoquinonas y evaluación de estos compuestos frente a epimastigotes de Trypanosoma cruzi, promastigotes de Leishmania (Leishmania amazonensis) y citotoxicidad a células LLCMK2. Resultados: Se sintetizaron nueve derivados de 1,4-naftoquinonas usando 2-bromo-1,4-naftoquinona (1), 1,4-naftoquinona (5) y 2-hidroxi-1,4-naftoquinona (9) como material de partida. El derivado 6a exhibió una excelente actividad tripanocida, CI50 de 0,25 ± 0,02 µM, potencia superior en comparación con el fármaco de referencia Benznidazol. Además, estos compuestos mostraron una baja actividad contra el promastigote de L. amazonensis. Conclusión: Los resultados indican que el compuesto 6a puede tener potencial como agente contra la enfermedad de Chagas.

Introdução: A doença de Chagas e a leishmaniose são doenças negligenciadas causadas pelos parasitas Trypanosoma cruzi e kentoplastídeos Leishmania spp. As doenças parasitárias causam grande impacto social e econômico, afetando milhões de pessoas no mundo e representam um dos maiores problemas de saúde global. Na busca por novas alternativas para o tratamento da Leishmaniose e da doença de Chagas, estratégias têm sido utilizadas para descobrir novas moléculas ativas, porque há urgência no desenvolvimento de novos fármacos. Nesse cenário, as 1,4-nafto-quinonas têm mostrado notável atividade no contexto das doenças negligenciadas. Objetivos: Sintetizar derivados de 1,4-naftoquinonas e avaliar esses compostos contra epimastigotas de Trypanosoma cruzi, promastigotas de Leishmania (Leishmania amazonensis) e citotoxicidade para células LLCMK2. Resultados: Nove derivados de 1,4-naftoquinonas foram sintetizados usando 2-Bromo-1,4-naftoquinona (1), 1,4-Naftoquinona (5) e 2-Hidroxi-1,4-naftoquinona (9) como material de partida. O derivado 6a exibiu excelente atividade tripanocida, IC50 de 0,25 ± 0,02 µM, potência superior em comparação com o medicamento de referência Benzonidazol. Além disso, esses compostos apresentaram baixa atividade contra a forma promasti-gota de L. amazonensis. Conclusão: Os resultados indicam que o composto 6a pode ter potencial para agente contra a doença de Chagas.

Unnexins: Homologs of innexin proteins in Trypanosomatidae parasites.

Large-pore channels, including those formed by connexin, pannexin, innexin proteins, are part of a broad family of plasma membrane channels found in vertebrates and invertebrates, which share topology features. Despite their relevance in parasitic diseases such as Chagas and malaria, it was unknown whether these large-pore channels are present in unicellular organisms. We identified 14 putative proteins in Trypanosomatidae parasites as presumptive homologs of innexin proteins. All proteins possess the canonical motif of the innexin family, a pentapeptide YYQWV, and 10 of them share a classical membrane topology of large-pore channels. A sequence similarity network analysis confirmed their closeness to innexin proteins. A bioinformatic model showed that a homolog of Trypanosoma cruzi (T. cruzi) could presumptively form a stable octamer channel with a highly positive electrostatic potential in the internal cavities and extracellular entrance due to the notable predominance of residues such as Arg or Lys. In vitro dye uptake assays showed that divalent cations-free solution increases YO-PRO-1 uptake and hyperosmotic stress increases DAPI uptake in epimastigotes of T. cruzi. Those effects were sensitive to probenecid. Furthermore, probenecid reduced the proliferation and transformation of T. cruzi. Moreover, probenecid or carbenoxolone increased the parasite sensitivity to antiparasitic drugs commonly used in therapy against Chagas. Our study suggests the existence of innexin homologs in unicellular organisms, which could be protein subunits of new large-pore channels in unicellular organisms.

In Vitro Phenotypic Activity and In Silico Analysis of Natural Products from Brazilian Biodiversity on Trypanosoma cruzi.

Chagas disease (CD) affects more than 6 million people worldwide. The available treatment is far from ideal, creating a demand for new alternative therapies. Botanical diversity provides a wide range of novel potential therapeutic scaffolds. Presently, our aim was to evaluate the mammalian host toxicity and anti-Trypanosoma cruzi activity of botanic natural products including extracts, fractions and purified compounds obtained from Brazilian flora. In this study, 36 samples of extracts and fractions and eight pure compounds obtained from seven plant species were evaluated. The fraction dichloromethane from Aureliana fasciculata var. fasciculata (AFfPD) and the crude extract of Piper tectoniifolium (PTFrE) showed promising trypanosomicidal activity. AFfPD and PTFrE presented EC50 values 10.7 ± 2.8 µg/mL and 12.85 ± 1.52 µg/mL against intracellular forms (Tulahuen strain), respectively. Additionally, both were active upon bloodstream trypomastigotes (Y strain), exhibiting EC50 2.2 ± 1.0 µg/mL and 38.8 ± 2.1 µg/mL for AFfPD and PTFrE, respectively. Importantly, AFfPD is about five-fold more potent than Benznidazole (Bz), the reference drug for CD, also reaching lower EC90 value (7.92 ± 2.2 µg/mL) as compared to Bz (23.3 ± 0.6 µg/mL). Besides, anti-parasitic effect of eight purified botanic substances was also investigated. Aurelianolide A and B (compounds 1 and 2) from A. fasciculata and compound 8 from P. tuberculatum displayed the best trypanosomicidal effect. Compounds 1, 2 and 8 showed EC50 of 4.6 ± 1.3 µM, 1.6 ± 0.4 µM and 8.1 ± 0.9 µM, respectively against intracellular forms. In addition, in silico analysis of these three biomolecules was performed to predict parameters of absorption, distribution, metabolism and excretion. The studied compounds presented similar ADMET profile as Bz, without presenting mutagenicity and hepatotoxicity aspects as predicted for Bz. Our findings indicate that these natural products have promising anti-T. cruzi effect and may represent new scaffolds for future lead optimization.

Characterization of Female External Genitalia and Eggs of Four South American Species of the Triatoma Laporte, 1832 Genus (Hemiptera: Reduviidae: Triatominae).

Triatoma is the most diversified and one of the most important genera from an epidemiological perspective. Given the difficulty in identifying some species of the Triatoma genus, morphological, histological, and morphometric studies were performed to provide new characters that make it possible to differentiate T. garciabesi, T. guasayana, T. patagonica, and T. sordida sensu stricto, triatomines that overlap geographically and have vector potential. Through the external female genitalia, as well as morphology, morphometry, and histology of eggshells, it was possible to discriminate the four species. In addition, this study reinforces the taxonomic validity of T. garciabesi and provides new data for discussion on systematic issues of T. guasayana and T. patagonica.

Anti-parasitic drugs modulate the non-selective channels formed by connexins or pannexins.

The proteins connexins, innexins, and pannexins are the subunits of non-selective channels present in the cell membrane in vertebrates (connexins and pannexins) and invertebrates (innexins). These channels allow the transfer of ions and molecules across the cell membrane or, and in many cases, between the cytoplasm of neighboring cells. These channels participate in various physiological processes, particularly under pathophysiological conditions, such as bacterial, viral, and parasitic infections. Interestingly, some anti-parasitic drugs also block connexin- or pannexin-formed channels. Their effects on host channels permeable to molecules that favor parasitic infection can further explain the anti-parasitic effects of some of these compounds. In this review, the effects of drugs with known anti-parasitic activity that modulate non-selective channels formed by connexins or pannexins are discussed. Previous studies that have reported the presence of these proteins in worms, ectoparasites, and protozoa that cause parasitic infections have also been reviewed.

Metallodrugs for the Treatment of Trypanosomatid Diseases: Recent Advances and New Insights.

Trypanosomatid parasites are responsible for many Neglected Tropical Diseases (NTDs). NTDs are a group of illnesses that prevail in low-income populations, such as in tropical and subtropical areas of Africa, Asia, and the Americas. The three major human diseases caused by trypanosomatids are African trypanosomiasis, Chagas disease and leishmaniasis. There are known drugs for the treatment of these diseases that are used extensively and are affordable; however, the use of these medicines is limited by several drawbacks such as the development of chemo-resistance, side effects such as cardiotoxicity, low selectivity, and others. Therefore, there is a need to develop new chemotherapeutic against these tropical parasitic diseases. Metal-based drugs against NTDs have been discussed over the years as alternative ways to overcome the difficulties presented by approved antiparasitic agents. The study of late transition metal-based drugs as chemotherapeutics is an exciting research field in chemistry, biology, and medicine due to the ability to develop multitarget antiparasitic agents. The evaluation of the late transition metal complexes for the treatment of trypanosomatid diseases is provided here, as well as some insights about their mechanism of action.

Cardiac Magnetic Resonance in the Assessment of Chagas Disease and its Complications

Abstract The well-known occurrence of Chagas disease in endemic areas has become a worldwide problem, and cardiac magnetic resonance allows the early detection of cardiac involvement and complications of this disease. Cardiac magnetic resonance is a useful tool in all phases of Chagas disease, and new promising techniques using T1 mapping and extracellular volume measurements are able to detect cardiac involvement even earlier than conventional techniques.

Revisiting the genetic variability of Brazilian peridomestic populations of the Chagas disease vector Triatoma sordida () (Hemiptera, Triatominae).

Triatoma sordida is an endemic species to South America, currently considered the species most frequently found in the peridomestic environment in Brazil. This triatomine has a wide ecological tolerability that allows it to inhabit several ecotopes and use different food sources. Although the species is considered predominantly peridomestic, it is also capable of colonizing households and forming numerous intra-household colonies, leading to its inclusion among the priorities for triatomine control campaigns in Brazil. All Brazilian populations of T. sordida are considered as T. sordida sensu stricto by chromosomal analyses (which highlights their epidemiological importance), although molecular studies that characterize the genetic diversity of these populations are scarce, being restricted only to the region of Minas Gerais. Thus, several populations of this vector distributed in the states of Bahia, Goiás, Mato Grosso do Sul, and Minas Gerais were analyzed using mitochondrial markers (cyt b and nd1). Low nucleotide diversity, high haplotypic diversity, low genetic distance, and high FST value were observed, as well as the formation of a monophyletic clade of the Brazilian populations of T. sordida, which confirms that this species has low genetic variability, with all specimens in Brazil grouped in T. sordida sensu stricto. In addition to the genetic and evolutionary importance for the knowledge of the biology of these vectors, these results are important from an epidemiological point of view, thus being able to direct vector control programs.

In Silico Drug Repositioning for Chagas Disease.

Chagas disease is an infectious tropical disease included within the group of neglected tropical diseases. Though historically endemic to Latin America, it has lately spread to high-income countries due to human migration. At present, there are only two available drugs, nifurtimox and benznidazole, approved for this treatment, both with considerable side-effects (which often result in treatment interruption) and limited efficacy in the chronic stage of the disease in adults. Drug repositioning involves finding novel therapeutic indications for known drugs, including approved, withdrawn, abandoned and investigational drugs. It is today a broadly applied approach to develop innovative medications, since indication shifts are built on existing safety, ADME and manufacturing information, thus greatly shortening development timeframes. Drug repositioning has been signaled as a particularly interesting strategy to search for new therapeutic solutions for neglected and rare conditions, which traditionally present limited commercial interest and are mostly covered by the public sector and not-for-profit initiatives and organizations. Here, we review the applications of computer-aided technologies as systematic approaches to drug repositioning in the field of Chagas disease. In silico screening represents the most explored approach, whereas other rational methods such as network-based and signature-based approximations have still not been applied.

Trypanosoma cruzi infection in puerperal women and their neonates at Barcelona, Anzoategui State, Venezuela / Infección por Trypanosoma cruzi en mujeres puérperas y sus neonatos en Barcelona, estado Anzoátegui, Venezuela

Introduction. Trypanosoma cruzi is mainly transmitted by vectors. Other pathways such as oral and congenital transmission have become increasingly relevant. Objective. To evaluate T. cruzi infections in post-partum women and their newborns who attended the Hospital Universitario Dr. Luis Razetti (Barcelona, Anzoátegui state, Venezuela). Materials and methods. A prospective cross-sectional study was undertaken from May, 2015, to August, 2016. ELISA, MABA and IFI assays were used to determine the infection in 1,200 post-partum women. The newborns of seropositive women were then examined for T. cruzi by PCR amplification and serological tests at nine months old. The prevalence of the parasitic infection in post-partum women and their newborns was then estimated. To establish the relationship between risk factors and infection, the chi-square test (c2) and the probability ratio (OR) was applied. Results. A total of 78 women were identified as seropositive (6.50 %) (CI 95%: 5.10-7.89%), and parasitic DNA was detected in six of their newborns (9.09%). Nine months after birth eleven infants were examined, and all were found to be serologically negative. Risk factors detected were pregnancy duration (OR: 0,36; CI95%: 0,15-0,84), where the patients lived at present (OR: 0,34; CI95%: 0,24-0,62) or previously (OR: 2,50; CI95%: 1,38-4,52) and having relatives with Chagas disease (OR: 1,75; CI95%: 1,02-3,01). Conclusions. Seroprevalence for T. cruzi infection in young post-partum women in rural areas was high. The detection of parasite DNA at birth was not indicative of congenital Chagas disease.

Introducción. Trypanosoma cruzi se transmite principalmente por vía vectorial, sin embargo, las rutas oral y congénita han tomado relevancia. Objetivo. Evaluar la infección por T. cruzi en mujeres puérperas y sus neonatos en el Hospital Universitario Dr. Luis Razetti de Barcelona, estado Anzoátegui, Venezuela. Materiales y métodos. Se hizo un estudio prospectivo de corte transversal, de mayo de 2015 a agosto de 2016, en el que se evaluaron 1.200 mujeres para determinar la infección mediante las pruebas ELISA, MABA e IFI. Los neonatos de las madres seropositivas se evaluaron con la prueba de PCR y por serología a los nueve meses de edad. Se estimó la prevalencia de la infección por T. cruzi en mujeres puérperas y sus neonatos. Para establecer los factores de riesgo asociados a la infección, se usó la prueba de ji al cuadrado (c2) y la razón de probabilidad (OR). Resultados. En total, 78 (6,50 %) mujeres resultaron positivas (IC95% 5,10-7,89 %). En seis (9,09 %) recién nacidos de madres seropositivas, se detectó ADN parasitario. Tras nueve meses de nacidos, once lactantes evaluados resultaron serológicamente negativos. La infección estuvo asociada con la duración del embarazo (OR=0,36; IC95% 0,15-0,84), origen del domicilio actual (OR=0,34; IC95% 0,24-0,62) o previo (OR=2,50; IC95% 1,38-4,52) y el tener familiares con la enfermedad de Chagas (OR=1,75; IC95% 1,02-3,01). Conclusiones. La seroprevalencia para la infección por T. cruzi en mujeres puérperas del medio rural, fue elevada. La detección de ADN parasitario al momento del nacimiento no es indicativa de enfermedad de Chagas congénita.

Infección por Trypanosoma cruzi en mujeres puérperas y sus neonatos en Barcelona, estado Anzoátegui, Venezuela / Trypanosoma cruzi infection in puerperal women and their neonates at Barcelona, Anzoategui State, Venezuela

Introducción. Trypanosoma cruzi se transmite principalmente por vía vectorial, sin embargo, las rutas oral y congénita han tomado relevancia. Objetivo. Evaluar la infección por T. cruzi en mujeres puérperas y sus neonatos en el Hospital Universitario Dr. Luis Razetti de Barcelona, estado Anzoátegui, Venezuela. Materiales y métodos. Se hizo un estudio prospectivo de corte transversal, de mayo de 2015 a agosto de 2016, en el que se evaluaron 1.200 mujeres para determinar la infección mediante las pruebas ELISA, MABA e IFI. Los neonatos de las madres seropositivas se evaluaron con la prueba de PCR y por serología a los nueve meses de edad. Se estimó la prevalencia de la infección por T. cruzi en mujeres puérperas y sus neonatos. Para establecer los factores de riesgo asociados a la infección, se usó la prueba de ji al cuadrado (c2) y la razón de probabilidad (OR). Resultados. En total, 78 (6,50 %) mujeres resultaron positivas (IC95% 5,10-7,89 %). En seis (9,09 %) recién nacidos de madres seropositivas, se detectó ADN parasitario. Tras nueve meses de nacidos, once lactantes evaluados resultaron serológicamente negativos. La infección estuvo asociada con la duración del embarazo (OR=0,36; IC95% 0,15-0,84), origen del domicilio actual (OR=0,34; IC95% 0,24-0,62) o previo (OR=2,50; IC95% 1,38-4,52) y el tener familiares con la enfermedad de Chagas (OR=1,75; IC95% 1,02-3,01). Conclusiones. La seroprevalencia para la infección por T. cruzi en mujeres puérperas del medio rural, fue elevada. La detección de ADN parasitario al momento del nacimiento no es indicativa de enfermedad de Chagas congénita.

Introduction. Trypanosoma cruzi is mainly transmitted by vectors. Other pathways such as oral and congenital transmission have become increasingly relevant. Objective. To evaluate T. cruzi infections in post-partum women and their newborns who attended the Hospital Universitario Dr. Luis Razetti (Barcelona, Anzoátegui state, Venezuela). Materials and methods. A prospective cross-sectional study was undertaken from May, 2015, to August, 2016. ELISA, MABA and IFI assays were used to determine the infection in 1,200 post-partum women. The newborns of seropositive women were then examined for T. cruzi by PCR amplification and serological tests at nine months old. The prevalence of the parasitic infection in post-partum women and their newborns was then estimated. To establish the relationship between risk factors and infection, the chi-square test (c2) and the probability ratio (OR) was applied. Results. A total of 78 women were identified as seropositive (6.50 %) (CI 95%: 5.10-7.89%), and parasitic DNA was detected in six of their newborns (9.09%). Nine months after birth eleven infants were examined, and all were found to be serologically negative. Risk factors detected were pregnancy duration (OR: 0,36; CI95%: 0,15-0,84), where the patients lived at present (OR: 0,34; CI95%: 0,24-0,62) or previously (OR: 2,50; CI95%: 1,38-4,52) and having relatives with Chagas disease (OR: 1,75; CI95%: 1,02-3,01). Conclusions. Seroprevalence for T. cruzi infection in young post-partum women in rural areas was high. The detection of parasite DNA at birth was not indicative of congenital Chagas disease.

First report of family clusters of Chagas disease seropositive blood donors in Mexico City and their epidemiological relevance.

BACKGROUND: Chagas disease is an important health problem in Latin America. Relatives of T. cruzi seropositive donors could also test positive in serological assays. Therefore, the study of Chagas diseases in family clusters has become important to accurately evaluate the problem that this infectious disease represents. OBJECTIVE: to investigate family cluster from blood donors, their serological, clinical and epidemiological status. METHODS: 53 family clusters consisting of index case and a variable number of relatives were studied. All the participants had ELISA and Western blot assays, as well as, clinical tests including an electrocardiogram and chest x ray. RESULTS: We found that 24.52% of the family clusters had at least one T. cruzi seropositive family member, in addition to the blood donor. Importantly, 20.75% of the index cases and 5.0% of the relatives presented pathological manifestations associated to Chagas disease. Several epidemiological conditions are associated to being T. cruzi seropositive. CONCLUSION: blood donor's family clusters have several seropositive to T. cruzi members. Mother-child pairs were also seropositive, suggesting vertical transmition. Pathological symptom associated to Chagas Diseases were present in index cases and family member. These results highlight the importance of studying family clusters to clarify the true magnitude of Chagas disease in Mexico.

Aim for the Readers! Bromodomains As New Targets Against Chagas' Disease.

Bromodomains recognize and bind acetyl-lysine residues present in histone and non-histone proteins in a specific manner. In the last decade they have raised as attractive targets for drug discovery because the miss-regulation of human bromodomains was discovered to be involved in the development of a large spectrum of diseases. However, targeting eukaryotic pathogens bromodomains continues to be almost unexplored. We and others have reported the essentiality of diverse bromodomain- containing proteins in protozoa, offering a new opportunity for the development of antiparasitic drugs, especially for Trypansoma cruzi, the causative agent of Chagas' disease. Mammalian bromodomains were classified in eight groups based on sequence similarity but parasitic bromodomains are very divergent proteins and are hard to assign them to any of these groups, suggesting that selective inhibitors can be obtained. In this review, we describe the importance of lysine acetylation and bromodomains in T. cruzi as well as the current knowledge on mammalian bromodomains. Also, we summarize the myriad of small-molecules under study to treat different pathologies and which of them have been tested in trypanosomatids and other protozoa. All the information available led us to propose that T. cruzi bromodomains should be considered as important potential targets and the search for smallmolecules to inhibit them should be empowered.

¿Puede considerarse portadores asintomáticos a los donantes de sangre seropositivos para Trypanosoma cruzi?: un estudio de validación en el proyecto CHICAMOCHA / Can Seropositive Blood Donors be Considered Asymptomatic Carriers for Trypanosoma cruzi?: a validation study in CHICAMOCHA project / Poderiam ser considerados portadores assintomáticos os doadores de sangue soropositivos para Trypanosoma cruzi? um estudo de validação no projeto CHICAMOCHA

Identificar el deterioro clínico de individuos seropositivos para la enfermedad de Chagas requiere observar la evolución de personas con infección establecida por Trypanosoma cruzi (T.cruzi), libres de signos y síntomas de cardiomiopatía en una línea de base. Objetivo: Realizar una comparación entre donantes de bancos de sangre de Bucaramanga con serología positiva y negativa para T. cruzi. Metodología: La muestra consistio en donantes elegibles con pruebas de tamización positivas para T. cruzi, pero negativas para otros agentes infecciosos tamizados por los bancos de sangre. Estos registros fueron apareados con una muestra aleatoria 1:4 de donantes con pruebas negativas a todas las pruebas de tamizaci¾n. Los participantes fueron entrevistados para conocer aspectos sociodemográficos y de percepción de su estado de salud, se realizó examen físico y se tomaron muestras de sangre para examenes paraclínicos. Se reportaron las frecuencias y proporciones de los participantes. Se hicieron pruebas de hipótesis de no diferencias entre los dos grupos con la prueba Chi cuadrado, con un nivel alfa de significancia de 5%. Resultados: La muestra consistió en 2,132 donantes de sangre incluidos entre mayo de 2000 y marzo de 2004. Mediante prueba serológica se identificaron 488 (22.9%) seropositivos y 1644 (77.1%) seronegativos. Los seropositivos fueron mayores en edad, presentaron indicadores socioeconómicos menos favorables y menor afiliación a seguridad social con el régimen contributivo y tenÝan una mejor percepción de su salud en comparación con los seronegativos (p<0.05). No se observaron diferencias estadísticamente significativas en cuanto a la percepción del funcionamiento de los tres sistemas evaluados (cardiovascular, urinario y gastrointestinal) en ambos grupos.

In order to identify the clinical deterioration of seropositive individuals for Chagas disease, it is necessary to observe the evolution of people infected by Trypanosoma cruzi (T. cruzi), who do not show signs and symptoms of cardiomyopathy on a baseline. Objective: To compare blood donors with positive and negative serology for Trypanosoma cruzi in the city of Bucaramanga. Methodology: The sample consisted of eligible donors with positive screening tests for T. cruzi, but negative for other infectious agents screened by blood banks. These records were matched with a random sample 1: 4 donors who showed negative results to all the screening tests. Participants were interviewed to know their socio-demographic aspects and to get a perception of their health status. Physical exams were performed and blood samples were taken for laboratory tests. Frequencies and proportions of participants were reported. Hypothesis testing of no differences between the two groups using the Chi square test was performed, showing a 5% level of alpha significance. Resultados: The sample included 2132 blood donors between May 2000 and March 2004. By using serological tests, it was identified that 488 (22.9%) were seropositive and 1644 (77.1%) were seronegative. Seropositive donors were older people who belonged to a low socio-economic level and had no health insurance. They also had a better perception of their health compared to seronegative donors (p <0.05). The perception of how the three evaluated systems worked (cardiovascular, urinary and gastrointestinal) showed no statistically significant differences between the two groups. Conclusions: The study findings allow us to infer that seropositive blood donors for T. cruzi could be considered as asymptomatic carriers without clinical evidence of cardiomyopathy.

Para identificar o deterioro clínico dos indivíduos soropositivos para a doença de Chagas Ú necessério acompanhar a evolução de indivíduos com infecção estabelecida pelo Trypanosoma cruzi (T. cruzi), livres de sinais e sintomas de cardiomiopatia numa linha de base. Objetivo: Fazer uma comparação entre os doadores dos bancos de sangue de Bucaramanga com sorologia positiva e negativa para T. cruzi. Metodologia: A amostra consistiu de doadores elegíveis com rastreamento positivo para T. cruzi, porém negativo para outros agentes infecciosos selecionados pelos bancos de sangue. Esses registros foram emparelhados com uma amostra aleatória de 1: 4 com testes negativos a todos os testes da triagem de doadores. Os participantes foram entrevistados para se conhecer aspectos sociodemográficos e perceber seus aspectos de saúde, foi realizado um exame físico e foram coletadas amostras de sangue para exames de laboratório. Relataram-se as frequéncias e proporções de participantes. Foi feito um teste de hipóteses de não diferenças entre os dois grupos com o teste do chi-quadrado, com um nível alfa de significãncia de 5%. Resultados: A mostra consistiu em 2132 doadores de sangue incluídos entre maio de 2000 e marþo de 2004. Pela prova sorol¾gica identificaram-se 488 (22.9%) soropositivos y 1644 (77.1%) soronegativos. Os Soropositivos foram maiores de 18 anos, tinham indicadores socioeconómicos menos favoróveis, menor inscrição no seguro social com o regime contributivo e melhor percepção da sua saúde em relação aos soronegativos (p <0,05). Estatisticamente não se observaram diferenças significativas quanto Ó percepção do funcionamento dos trés sistemas avaliados (cardiovascular, gastrointestinal e urinário) em ambos os grupos. Concluções: resultados do estudo permitem concluir que os doadores soropositivos para T. cruzi no sangue poderiam ser vistos como portadores assintomáticos, sem evidência clínica de cardiomiopatia.

Caracterização molecular de cepas de Trypanosoma Cruzi isolada na zona urbana da cidade de Salvador/BA / Molecular characterization of Trypanosoma cruzi isolated from strains in the urban area of the city of Salvador / Ba

A Doença de Chagas é uma infecção parasitária causada pelo protozoário flagelado Trypanosoma cruzi. As cepas de T. cruzi se constituem de uma população heterogênea, apresentando várias subpopulações. Essas populações circulam entre animais vertebrados domésticos, silvestres e humanos, além de insetos vetores. Devido a essas múltiplas relações, o T. cruzi demostra uma grande variedade biológica, genética, bioquímica e imunológica. A caracterização das cepas de T. cruzi pode utilizar várias metodologias que pode ter foco biológico, bioquímico, isoenzimático e molecular. Dentre essas, a molecular vem ganhando destaque devido a rapidez, sensibilidade e precisão do método. Deste modo, com a presente pesquisa o objetivo foi caracterizar molecularmente as cepas de Tripanosoma cruzi (Chagas 1909) isoladas em vetores e reservatórios na zona urbana de Salvador. Foram incluídas neste estudo amostras de T. cruzi isoladas de triatomíneos e reservatórios provenientes de diversas localidades da cidade de Salvador, capturados entre Julho de 2007 e Junho de 2011, perfazendo um total de 4 anos de amostragem. Adotamos a técnica de tipagem molecular do T. cruzi sugerida por Zingales et al. (2009) em sistema de eletroforese capilar. Das 930 amostras de triatomíneos avaliados, 99,35% da espécie Triatoma tibiamaculata, 482 amostras (52%)...

Chagas disease is a parasitic infection caused by the flagellate protozoan Trypanosoma cruzi. The T. cruzi strains constitute a heterogeneous population, with several subpopulations. These populations move between domestic vertebrate animals, wildlife and humans, and insect vectors. Because of these multiple relationships, T. cruzi demonstrates great biological diversity, genetic, biochemical and immunological. The characterization of T. cruzi strains can use various methodologies that may have biological, biochemical, and molecular isoenzyme focus. Among these, the molecular been gaining attention due to speed, sensitivity and precision of the method. Thus, the present study the objective was to characterize molecularly strains of Trypanosoma cruzi (Chagas 1909) isolated in vectors and reservoirs in the urban area of Salvador. Were included in this study T. cruzi samples of insects and shells from different localities of the city of Salvador, captured between July 2007 and June 2011, a total of four years of sampling. We adopt molecular typing technique of T. cruzi suggested by Zingales et al. (2009) in a capillary electrophoresis system. Of the 930 samples evaluated triatomine 99.35% of Triatoma tibiamaculata, 482 samples (52%)...

Transmisión congénita de la enfermedad de Chagas en el Paraguay / Congenital transmission of Chagas disease in Paraguay

Las estrategias actuales recomendadas para el diagnostico de la infección congénita chagásica requieren del diagnóstico serológico convencional en mujeres embarazadas para detectar su infección y la confirmación parasitológica en recién nacidos infectados verticalmente. La detección de parásitos en sangre no resulta un método fácil de aplicar a gran escala y a nivel de salud pública por lo que se recomienda finalmente la serología convencional, es decir la detección de IgG anti-T. cruzi en infantes mayores a 8 meses de edad. Teniendo en cuenta estas recomendaciones nuestro grupo ha diseñado estrategias operativas en áreas rurales endémicas que permiten la rápida detección y tratamiento de infantes infectados congénitamente. Demostramos que la descentralización de los estudios serológicos de los grandes Hospitales Regionales ayuda a la rápida identificación de las mujeres infectadas, como también el registro de su estado de infección en las fichas familiares, prenatal y pediátrica. Los resultados de más de 15 años de estudio de nuestro grupo, indican que a pesar de la alta sensibilidad de la técnica reacción en cadena de la polimerasa (PCR), resulta muy complejo su empleo con fines de diagnóstico a nivel rural y en gran escala, siendo muy útil para evaluar el tratamiento realizado en los niños infectados. La serología convencional permite la detección inequívoca de anticuerpos del tipo IgG en infantes infectados congénitamente después de los 8 meses de edad (tiempo máximo observado para el clearence de anticuerpos maternos). Sin embargo esta estrategia hace que el tiempo requerido en el seguimiento para descartar transmisión congénita disminuya la adherencia durante el periodo de seguimiento con una importante pérdida de niños que no son traídos al control. La detección de casos de transmisión congénita aumenta notablemente cuando se utiliza una combinación de las técnicas serológicas convencionales y un ELISA que hemos diseñado con el antígeno recombinante de fase aguda, “shed acute phase antigen” (SAPA) que permite la detección inequívoca de infantes infectados congénitamente a los 3 meses de edad

The current strategies recommended for the diagnosis of congenital Chagas disease require the conventional serological diagnosis in pregnant women to detect their infection and the parasitological confirmation in the congenitally infected newborns. The detection of parasites in blood is not a method easy to apply at large scale and at public health level. Therefore, the conventional serology is recommended, i.e. detection of anti-T.cruzi IgG in infants older than eight months of age. Considering these recommendations, our group has designed operative strategies in endemic rural areas that allow the rapid detection and treatment of congenitally infected infants. We have demonstrated that the decentralization of the serological studies from the Regional Hospitals contributes to the fast identification of the infected women together with the registration of their infection status in the family, prenatal and pediatric files. The results of over fifteen years of study of our group indicate that, in spite of the high sensitivity of PCR, its use with diagnosis purposes is very complex at large scale and in rural areas. However, the polymerase chain reaction (PCR) technique is very useful to evaluate the treatment of infected children. The conventional IgG serology allows the unequivocal detection of congenitally infected infants after eight months of age (maximum time observed for the clearance of maternal antibodies). However, this strategy makes that the time required to rule out a congenital transmission in the follow-up diminishes adherence with an important loss of children that are not brought to control. The detection of congenital transmission cases increases remarkably when a combination of the conventional serological techniques and an ELISA that we designed with the recombinant protein “shed acute phase antigen” (SAPA) is used, allowing the unequivocal detection of congenitally infected children at three months of age