Triatomine vectors of Trypanosoma cruzi in an endemic area for Chagas disease in Northeast Brazil

ABSTRACT Background: We assessed the distribution of triatomines in an endemic area for Chagas disease. Methods: This retrospective study used secondary data extracted from the Official System of the National Chagas Disease Control Program (Sistema Oficial do Programa Nacional de Controle da Doença de Chagas - SisPCDCh). Results: A total of 7,257 (725.7 ± 221.7 per year) specimens were collected from 2013 to 2022. Most of them (6,792; 93.6%) were collected in the intradomicile and 465 (6.4%) in the peridomicile. A total of 513 (7.1%) triatomines tested positive for the presence of trypomastigote forms, similar to Trypanosoma cruzi. Conclusions: The spatial analysis revealed a heterogeneous distribution of triatomines across different municipalities.

Research progress of Triatoma rubrofasciata, the vector of Chagas disease / 中华地方病学杂志

Chagas disease (also known as American trypanosomiasis) is a zoonotic disease caused by Trypanosoma cruzi. It has a long incubation period and low diagnosis rate. At present, there is no vaccine to prevent it, and there is no specific drug at the late stage of the disease. Therefore, some scholars call it "new AIDS". In the past two decades, Chagas disease has spread from the main epidemic area of Latin America to other non-epidemic countries. At the same time, Triatoma rubrofasciata, one of its main vectors, is widely distributed in the world, including some humid and warm southern areas of China. Therefore, in this paper, the distribution characteristics, biology and molecular biology of Triatoma rubrofasciata are comprehensively reviewed, in order to provide reference for the prevention and control of imported Chagas disease in China.

First record of Triatoma longipennis, Usinger, 1939 (Hemiptera: Reduviidae: Triatominae) in Tecozautla, Hidalgo

ABSTRACT Background: We report the presence of Triatoma longipennis for the first time in two localities in Hidalgo, Mexico. Methods: This study was conducted at Tecozautla municipality, Hidalgo. Collection was performed in April 2022. Results: We collected eight triatomines from Guadalupe: two fourth-instar nymphs, three fifth-instar nymphs, one female, and two males. In San Miguel Caltepantla, a female was collected inside a dwelling. One sample tested positive for Trypanosoma cruzi. Conclusions: These findings suggest the need to investigate the dynamics of this species with respect to the inhabitants of the study area.

New records of Triatoma huehuetenanguensis in an urban area of Southwest Mexico

The recently described Triatoma huehuetenanguensis, has been reported in Mexico, Guatemala, Belize and Honduras. In Mexico, the species has been collected primarily in rural areas; it has the potential to colonize human dwellings, however, its contribution to Chagas outbreaks remains unclear. In 2021, T. huehuetenanguensis was first observed at Tuxtla Gutierrez city, Chiapas; then a collection for the species was performed. A total of 308 houses were inspected in the intra and peridomestic structures. Only 3 houses (0.97%) were infested. Triatoma huehuetenangensis was the only triatomine specie recorded and four males were collected. None of the bugs tested positive for Trypanosoma infection. We do not have evidence to suggest that urban human-vector contact still limited, and a possible domestication process is possible. The presence of reservoirs, the vector species and the parasite demonstrate that Tuxtla Gutierrez could be at risk of a Chagas disease outbreak.

Chromosomal karyotypes and C-band analysis of Triatoma rubrofasciata in China / 中国血吸虫病防治杂志

Objective To investigate the karyotypes and C bands of Triatoma rubrofasciata in China, so as to understand its chromosome number, morphology and C-band staining of T. rubrofasciata. Methods The testis specimens were sampled from male T. rubrofasciata collected from Shunde City, Guangdong Province, prepared into slides of metaphase chromosomes and subjected to Giemsa staining and C-band staining. The morphology of metaphase chromosomes and the location of heterochromatin were observed using microscopy, and the long arm and short arm of each chromosome and total chromosome length were recorded to analyze the karyotypes and C bands of T. rubrofasciata. Results The male T. rubrofasciata presented a chromosome number of 2n = 25, including 22 autosomes and 3 sex chromosomes. The relative length of chromosomes ranged from 3.59% to 12.76%, the arm ratio was 1.06 to 1.24, and the centromere index was 44.76% to 48.47%. All chromosomes were metacentric chromosomes and the karyotype formula was 2n = 22 metacentric + X1X2Y, and the C bands varied on different chromosomes. No heterochromatin was found in the X chromosome, and the overall staining appeared pale, while heterochromatin was detected in all regions of the Y chromosome, and the overall staining appeared dark. In addition, heterochromatin was present in both ends of the autosome. Conclusions The male T. rubrofasciata presents a chromosome number of 2n = 25 in China, and the karyotype formula is 2n = 22 metacentric + X1X2Y. C-banding shows dark staining of the Y chromosome, pale staining of the X chromosome, and dark staining of both ends of the autosome. Our data may provide insights into the investigation on the origin, evolution and gene mapping of T. rubrofasciata in China.

Phenotypic and genetic variation of Triatoma costalimai (Hemiptera: Reduviidae)

Abstract INTRODUCTION: We aimed to study intraspecific variation in Triatoma costalimai, a potential vector of Chagas disease present in Brazil and Bolivia. METHODS: We analyzed phenotypic (connexivum color patterns, wing morphometrics) and genetic variation (16S mtDNA) of three Brazilian T. costalimai populations. We compared 16S sequences with those of putative Bolivian T. costalimai and its sister species, T. jatai. RESULTS: Brazilian populations had different connexivum color patterns and forewing shapes. A 16S mtDNA haplotype network showed a clear separation of Brazilian T. costalimai from both T. jatai and Bolivian T. costalimai. CONCLUSIONS: We report considerable variability in T. costalimai populations.

Residual foci of Triatoma infestans infestation: Surveillance and control in Rio Grande do Sul, Brazil, 2001-2018

Abstract INTRODUCTION: This retrospective study conducted from 2001 to 2018 investigated the residual foci of Triatoma infestans infestation in Rio Grande do Sul, Brazil. METHODS: The data were obtained via entomological surveillance and the distribution of vector occurrence. The coverage of active research was mapped. RESULTS: The largest coverage rate for active research was observed in the northwest region of the total of 515,081 domiciles researched. Most T. infestans specimens were captured in the peridomicile. CONCLUSIONS: Infestation has decreased significantly since 2008, and T. infestans has not been captured since 2015.

Biogeographical factors determining Triatoma recurva distribution in Chihuahua, México, 2014 / Factores biogeográficos determinantes de la distribución de Triatoma recurva en Chihuahua, México, 2014

Introduction: Triatoma recurva is a Trypanosoma cruzi vector whose distribution and biological development are determined by factors that may influence the transmission of trypanosomiasis to humans. Objective: To identify the potential spatial distribution of Triatoma recurve, as well as social factors determining its presence. Materials and methods: We used the MaxEnt software to construct ecological niche models while bioclimatic variables (WorldClim) were derived from the monthly values of temperature and precipitation to generate biologically significant variables. The resulting cartography was interpreted as suitable areas for T. recurva presence. Results: Our results showed that the precipitation during the driest month (Bio 14), the maximum temperature during the warmest month (Bio 5), and the altitude (Alt) and mean temperature during the driest quarter (Bio 9) determined T. recurva distribution area at a higher percentage evidencing its strong relationship with domestic and surrounding structures. Conclusions. This methodology can be used in other geographical contexts to locate potential sampling sites where these triatomines occur.

Introducción. Triatoma recurva es un vector de Trypanosoma cruzi cuya existencia y desarrollo biológico están determinados por factores que pueden influir en la transmisión de la tripanosomiasis a los seres humanos. Objetivo. Determinar una posible distribución espacial de Triatoma recurva y algunos factores sociales que determinan su presencia. Materiales y métodos. El modelado de nicho ecológico se hizo con el programa MaxEnt empleando las variables bioclimáticas (WorldClim) derivadas de los valores mensuales de temperatura y precipitación para generar variables biológicamente significativas. La cartografía resultante evidenció áreas adecuadas para la presencia de T. recurva. Resultados. Los resultados indicaron que la precipitación del mes más seco (Bio 14), la temperatura máxima del mes más cálido (Bio 5), y la altitud (Alt) y la temperatura media del trimestre más seco (Bio 9), determinaron en mayor porcentaje el área de distribución de T. recurva, observándose que es una especie con una acentuada relación con las estructuras domésticas y circundantes. Conclusión. Esta metodología puede emplearse en otros contextos geográficos para localizar posibles sitios de muestreo de estos triatominos.

Determination of insecticides' lethal concentrations and metabolic enzyme levels in Triatoma dimidiata / Determinación de concentraciones letales y niveles de enzimas metabólicas de insecticidas en Triatoma dimidiata

Abstract: Objective: The feasibility of the use of WHO impregnated paper and biochemical assays to determine lethal concentrations (LC50 and LC99) and insecticide metabolic enzyme levels of Triatoma dimidiata. Materials and methods: LC50 and LC99 were calculated with WHO papers impregnated at different concentrations of malathion, propoxur and deltamethrin; the percentage of insensitive acetylcholinesterase (iAChE); and the levels of esterases, glutathione S-transferases, and monooxygenases in laboratory nymphs of the first stage (5 to 7 days), were undertaken using the WHO biochemical assays. Results: Respectively the LC50 and LC99 µg/cm2 obtained for malathion were 43.83 and 114.38, propoxur 4.71 and 19.29, and deltamethrin 5.80 and 40.46. A 30% of the population had an iAChE, and only a few individuals had high P450 and β-eterase levels. Conclusion: Impregnated papers and biochemical tests developed by WHO for other insects, proved to be feasible methods in monitoring insecticide resistance and metabolic enzymes involved in T. dimidiata.

Resumen: Objetivo: La factibilidad de usar los papeles impregnados y ensayos bioquímicos según la OMS para determinar concentraciones letales (CL50 y CL99) y niveles enzimáticos en la resistencia a insecticidas en Triatoma dimidiata. Material y métodos: Se calcularon la CL50 y CL99 con papeles impregnados según la OMS a diferentes concentraciones de malatión, propoxur y deltametrina; el porcentaje de acetilcolinesterasa insensible (iAChE); y los niveles de esterasas, glutatión S-transferasas, y monooxigenasas en ninfas de laboratorio del estadio I (5-7 días) se determinaron usando los ensayos bioquímicos según la OMS. Resultados: Se obtuvieron las CL50 y CL99 µg / cm2 respectivamente para malatión 43.83 y 114.38, propoxur 4.71 y 19.29, y deltametrina 5.80 y 40.46. Un 30% de las chinches tuvo iAChE, y sólo pocos individuos tuvieron niveles superiores de P450 y β-eterasas. Conclusión: Los papeles impregnados y ensayos bioquímicos que describe la OMS para otros insectos demostraron ser métodos factibles para monitorear la resistencia a insecticidas y las enzimas metabólicas involucradas en T. dimidiata.

Conocimientos sobre Enfermedad de Chagas y Triatoma infestans en Pobladores del Departamento de San Pedro, Paraguay 2019 / Knowledge about Chagas disease and Triatoma infestans in inhabitants of the Department of San Pedro, Paraguay 2019

La tripanosomiasis americana o enfermedad de Chagas, producida por el protozoo hemoflagelado Trypanosoma cruzi. En Paraguay el principal vector Triatoma infestans ("vinchuca" o "chichã guasu") es considerado, en términos sociales y económicos, una de las enfermedades parasitarias más importantes que pueden desencadenar complicaciones graves cardiológicas. Durante el Periodo 2014 al 2017 en el Departamento de San Pedro se registraron 302 casos de Enfermedad de Chagas detectados por serología. El objetivo del estudio estuvo dirigido a investigar el nivel de conocimiento de la población que, por su forma de vida, presentan factores de riesgo. Se realizó una investigación cualitativa exploratoria, con enfoque hermenéutico. La población de estudio estuvo conformada por 41 familias que residen en comunidades del Departamento de San Pedro, que se encuentran entre 15 km a 40 km de zonas urbanas, a quienes se le realizo una entrevista semi-estructurada en profundidad. Entre los resultados obtenidos se evidenció que: La mayoría de los pobladores de la zona conocen al triatoma y lo pudieron observar cuando eran niños y algunos afirman haber sido picados, pudiendo así describir la morfología y otras características del vector; la mayoría desconoce la sintomatología producida por el T. cruzi, pero tienen un conocimiento básico relacionado a la enfermedad.

The american trypanosomiasis, also known as Chagas disease, is caused by an hemophlagelated protozoo called Trypanosoma cruzi. In Paraguay, the most relevant vector is Triatoma infestans (vinchuca or "chichã guasu") is considered, in social and economic terms, one of the most important parasitic diseases which may cause severe cardiological complications. Since 2014 till 2017, in San Pedro´s department, have been registered 302 cases of Chagas disease, all detected by serology. The objective of this study was directed to investigate the degree of knowledge of the population that, because of their lifestyles, presents risk factors. It has been made a qualitative-exploratory investigation, with hermeneutic focus. The population studied was made up for 41 families which reside in communities of San Pedro´s department, that are located around 15/40 km of urban zones. They all had a deep semi-structured interview. The results showed that: most of the settlers know triatoma and could observe it when they were children and also some of them affirm have been chopped, being able to describe the morphology and other characteristics of the vector. Most of the interviewed unknown the symptomatology produced by T. cruzi, but have the basic knowledge related with this disease.

Impact of Kuntai Capsules on LIF, IGF-1 and EGF expression in the implantation window of endometrium in mice / Impacto de cápsulas de Kuntai en la expresión de LIF, IGF-1 y EGF en la ventana de implantación de endometrio en ratones

To investigate the influence of Kuntai capsules on the expression level of leukemia inhibitory factor (LIF), insulin-like growth factor-I (IGF-1)and epidermal growth factor (EGF) during the mouse's implantation window of superovulation period and controlled ovarian hyperstimulation period. 90 female mice were randomly divided into six groups in control, superovulation and controlled ovarian hyperstimulation (COH) conditions. The RNA expression of EGF, LIF and IGF-1 in the endometrium on the 4th day of pregnancy was detected, and the relative expression was compared. mRNA expression of these three factors in endometrium was significantly lower in superovulation and COH groups than control group (p<0.001). mRNA expression of these three factors in endometrium remained obviously lower in superovulation plus kuntai capsule group and COH plus kuntai capsule group than control group (p<0.01). mRNA expression of these three factors in endometrium was lower in control group than in the NS plus kuntai capsule group (p<0.05). Kuntai capsule cannot completely reverse the endometrial damages caused by superovulation and COH. Thus Kuntai capsule could partially improve a mouse's endometrial receptivity during the implantation window.

Para investigar la influencia de las cápsulas de Kuntai en el nivel de expresión del factor inhibidor de la leucemia (LIF), el factor de crecimiento similar a la insulina I (IGF-1) y el factor de crecimiento epidérmico (EGF) durante la ventana de implantación del ratón del período de superovulación y la hiperestimulación ovárica controlada período, se dividieron aleatoriamente 90 ratones hembra en seis grupos en condiciones de control, superovulación e hiperestimulación ovárica controlada (COH). Se detectó la expresión de ARN de EGF, LIF e IGF-1en el endometrio al cuarto día de embarazo, y se comparó la expresión relativa. La expresión de ARNm de estos tres factores en el endometrio fue significativamente menor en los grupos de superovulación y COH que en el grupo control (p<0,001). La expresión de ARNm de estos tres factores en el endometrio permaneció más baja en el grupo de cápsulas de superovulación más Kuntai y en el grupo de cápsulas de COH más Kuntai respecto del grupo control (p<0,01). La expresión de ARNm de estos tres factores en el endometrio fue menor en el grupo control que en el grupo de cápsula NS más Kuntai (p<0,05). La cápsula de Kuntai no pudo revertir completamente los daños endometriales causados por la superovulación y la COH. Por lo tanto, se sugiere que la cápsula de Kuntai podría mejorar parcialmente la receptividad endometrial de un ratón durante la ventana de implantación.

Efecto de la educación comunitaria para control integrado del Triatoma Dimidiata (Hemiptera: Reduviidae) / EEffect of community education in an integrate control for Triatoma dimidiata (Hemiptera: Reduviidae) / EEffect of community education in an integrate control for Triatoma dimidiata (Hemiptera: Reduviidae)

Introduction: The Mesoamerican endemic specieTriatoma dimidiata is the main vector of Chagas disease in Central America, after the elimination of an introduced vector Rhodnius prolixus. The traditional method of vector control using insecticides results in reinfestation. An integrated Ecohealth approach, including education, house improvements and domestic animal management was shown effective for long-term control ofT. dimidiata, and it was applied in several villages in Guatemala. Objective: To evaluate the changes in community practices after an Ecohealth intervention in La Prensa, Olopa Chiquimula. Methods: Through three surveys, we measured risk factors associated withT. dimidiatainfestation, the infestation index, blood sources of T. dimidiata, the presence of Trypanosoma cruzi were analyzed using PCR. Statistics analysis included Wilcoxon signed-rank tests, Mc-Nemar test, Chi-square test and Fisher exact test to compare the surveys. Results: Over the years, risk factors associated with the presence of T. dimidiata and population density of the vector were observed. We found a decrease in consumption of human blood and the parasite in the vector population. However, we found the consumption of bird blood meal increased Conclusions: Our results provide evidence that an ecohealth approach for an endemic Chagas vector has impact on reducing vector-human contact, possibly by influencing people's behavior. Increasing the community knowledge about these risk factors can be an effective strategy to further reduce the risk of house reinfestation and Chagas transmission(AU)

Introducción: La especie endémica mesoamericana Triatoma dimidiata es el vector principal de la enfermedad de Chagas en América Central, después de la eliminación de un vector introducido Rhodnius prolixus. El método tradicional de control de vectores que utiliza insecticidas resulta en reinfestación. Se demostró que un enfoque integrado de ecosalud, que incluye la educación, mejorías en el hogar y manejo de animales domésticos, es efectivo para el control a largo plazo del T. dimidiata, y se aplicó en varias aldeas de Guatemala. Objetivo: evaluar los cambios en las prácticas comunitarias después de una intervención de ecosalud en La Prensa, Olopa Chiquimula. Métodos: a través de tres encuestas, se midieron los factores de riesgo asociados con la infestación de T. dimidiata, el índice de infestación, las fuentes sanguíneas de T. dimidiata y la presencia de Trypanosoma cruzi. Estas encuestas se analizaron mediante PCR. El análisis estadístico incluyó pruebas de Wilcoxon de rango con signo, la prueba de Mc-Nemar, la prueba de Chi-cuadrado y la prueba exacta de Fisher para comparar las encuestas. Resultados: A lo largo de los años, se observaron factores de riesgo asociados con la presencia de T. dimidiata y la densidad de población del vector. Encontramos una disminución del parásito en la población de vectores y en el consumo de sangre humana. Sin embargo, encontramos que aumentó el consumo de harina de sangre de aves. Conclusiones: Nuestros resultados proporcionan evidencia de que un enfoque de ecosalud para un vector de Chagas endémico impacta en la reducción del contacto vector-humano, posiblemente al influir en el comportamiento de las personas. Aumentar el conocimiento de la comunidad sobre estos factores de riesgo puede ser una estrategia efectiva para reducir aun más el riesgo de reinfestación en la casa y la transmisión de Chagas(AU)

Revisión de más de 40 años de estudios en pacientes seropositivos para la enfermedad de Chagas en la provincia de Entre Ríos, Argentina / Review of more than 40 years of studies in seropositive patients for Chagas disease in the province of Entre Ríos, Argentina

El presente trabajo es una revisión de más de 40 años de investigación sobre los aspectos epidemiológicos, socioeconómicos y clínicos de la Enfermedad de Chagas en el Departamento Uruguay (Provincia de Entre Ríos). Se resumen las investigaciones sobre la presencia de vectores triatominos en viviendas urbanas y rurales donde se procedió a su identificación y búsqueda de Trypanosoma cruzi. Se describió la seroprevalencia de la enfermedad y su evolución a lo largo del tiempo. Se agregaron también aspectos cardiológicos y gastroenterológicos de pacientes en el período crónico de la enfermedad. La presencia de triatominos derivó en campañas de fumigación y de educación sanitaria, que provocaron un marcado descenso en el número de vectores capturados en los años siguientes. También se destacó el descenso de la seroprevalencia de la enfermedad de Chagas a través del tiempo, debido a las campañas de fumigación, educación sanitaria, controles en banco de sangre y embarazadas, mejora de las técnicas utilizadas y la aparición de tratamientos efectivos contra el parásito. Los estudios cardiológicos y gastroenterológicos de los pacientes crónicos mostraron alteraciones dentro de lo esperado para este estadio de la enfermedad. También se describió la detección de personas infectadas con acceso al tratamiento y los estudios cardiológicos y gastroenterológicos realizados en pacientes en estadio crónico. Por último, se considera que, globalmente, los estudios realizados en la zona han colaborado en lograr que la Provincia de Entre Ríos fuera declarada libre de transmisión vectorial en 2012.

This is a review of more than 40 years of research on the epidemiological, socioeconomic and clinical aspects of Chagas disease in the Department of Uruguay (Entre Ríos province). Research on the presence of triatomine vectors in urban and rural housing is summarized here.These vectors were identified and Trypanosoma cruzi was searched for. . The seroprevalence of the disease and its evolution over time were described. Cardiological and gastroenterological aspects of patients in the chronic period of the disease were also added. The presence of triatomines resulted in fumigation and health education campaigns, which caused a marked decrease in the number of vectors captured in the following years. The decrease in the seroprevalence of Chagas disease over time was also highlighted, due to fumigation campaigns, health education, blood bank and pregnant women controls, improvement of the techniques used and the development of effective treatments against the parasite. Cardiological and gastroenterological studies of chronic patients showed the abnormalities expected for this stage of the disease. The detection of infected persons with access to treatment and cardiological and gastroenterological studies performed in patients with chronic stage were also described. Finally, it is considered that, globally, the studies carried out in the area have helped to ensure that the Province of Entre Ríos be declared free of the vector transmission in 2012.

Este trabalho é uma revisão de mais de 40 anos de pesquisa sobre os aspectos epidemiológicos, socioeconômicos e clínicos da doença de Chagas no Departamento Uruguai (província de Entre Ríos). São resumidas as pesquisas sobre a presença de vetores de triatomíneos em moradias urbanas e rurais, onde foram identificados e pesquisados por Trypanosoma cruzi nelas. A soroprevalência da doença e sua evolução ao longo do tempo foram descritas. Também foram adicionados aspectos cardiológicos e gastroenterológicos dos pacientes no período crônico da doença. A presença de triatomíneos resultou em campanhas de fumigação e educação sanitária, o que causou uma redução acentuada no número de vetores capturados nos anos seguintes. Também foi destacada a diminuição da soroprevalência da doença de Chagas através do tempo, devido às campanhas de fumigação, educação sanitária, controles em bancos de sangue e gestantes, melhora das técnicas utilizadas e surgimento de tratamentos eficazes contra o parasita. Estudos cardiológicos e gastroenterológicos de pacientes crônicos mostraram alterações dentro do esperado para esse estágio da doença. Também foram descritas a detecção de pessoas infectadas com acesso ao tratamento e estudos cardiológicos e gastroenterológicos realizados em pacientes em estágio crônico. Por fim, consideramos que, globalmente, os estudos realizados na área ajudaram a garantir que a Província de Entre Ríos fosse declarada livre de transmissão vetorial em 2012.

Factors associated with the presence of triatomines in rural areas of south Argentine Chaco

Abstract INTRODUCTION: The domestic and peridomestic presence of Triatoma infestans depends on several factors, such as human behavior, vector behavior, ecology, and the environment. METHODS: This work was conducted in 139 domiciliary units, where triatomines were captured and risk factors in domiciles and peridomicilies were recorded. Household dwellers were interviewed to obtain information about practices regarding this disease and entomological indicators were calculated. RESULTS: Infestation indices were 59.7% for house compounds, 4.3% for domestic areas and 58.3% for the peridomestic areas. Intradomicile infestation was significantly associated with housing characteristics. The presence of chicken coops in peridomicilies was associated with an increased risk of infestation. Of the respondents, 80% did not recognize the importance of the peridomiciliary structures for triatomine control and had infested peridomicilies. CONCLUSIONS: The results show the importance of peridomiciles as refuge sites for Triatominae bugs; however, household dwellers do not perceive peridomiciles as areas that favor the presence of vectors. Actions for raising awareness about factors that favor the presence of triatomines are needed to improve the conditions of peridomiciliary environments.

Toxicidad y afectación en la locomoción de Triatoma dimidiata (Latreille 1811) (Hemiptera: Reduviidae: Triatominae) tratados con análogos de girgensohnina / Toxicity and affectation in locomotion of Triatoma dimidiata (Latreille 1811) (Hemiptera: Reduviidae: Triatominae) treated with analogues of girgensohnine

Resumen Introducción: Análogos del alcaloide girgensohnina, diseñados y sintetizados para inhibir a la enzima acetilcolinesterasa, han presentado efecto insecticida sobre insectos vectores de enfermedades. Objetivo: Determinar la actividad insecticida de 12 análogos sintéticos de gingersohnina sobre ninfas del primer estadio de Triatoma dimidiata. Materiales y Métodos: Se tomó como referencia el protocolo de la OMS 2005. Ninfas del primer estadio de T. dimidiata fueron expuestas a los análogos por aplicación tópica y exposición a superficies para determinar las dosis letales (DL50 y DL95) y verificar alteración en la locomoción mediante el software Videomex V. Resultados: El análogo 6 presentó la mayor actividad insecticida a las 72h con una mortalidad del 20,8% ± 3,57 para el tratamiento de topicación 25% ± 0,00 para las superficies no porosas. Las dosis letales de la molécula 6 fueron: DL50 1036,8 ± 0,38 ng/insecto y DL95 3991,4 ± 0,50 ng/insecto respectivamente. Con respecto a la locomoción, el análogo indujo un comportamiento similar al insecticida comercial deltametrina.

Abstract Introduction: Analogs of the girgensohnine alkaloid, designed and synthesized to inhibit acetylcholinesterase enzyme, have presented an insecticidal effect on vectors insects of diseases. Objective: To determine the insecticidal activity of 12 synthetic analogs of gingersohnine in first stage nymphs of Triatoma dimidiata. Materials and methods: WHO protocol 2005, using exploratory doses, was used to determine the best molecule according to its mortality. First stage nymphs of T. dimidiata were exposed to different doses of the analogs by topical application and surface exposure. Lethal doses (LD50 and DL95) and alterations in locomotion using Videomex V software were determined. Results: Analog 6 presented the highest insecticidal activity at 72 h with a mortality of 20.8% ± 3.57 for topical treatment and 25%±0,0 for non-porous surfaces evaluation. Analog 6 lethal doses were LD50 1036.8 ± 0.38 ng/insecto and DL95 3991.4 ± 0.508 ng/insecto, respectively. With regard to locomotion, analogue 6 induced a similar behavior to that observed for commercial insecticide deltametrin.

Assessing the risk zones of Chagas' disease in Chile, in a world marked by global climatic change

BACKGROUND Vector transmission of Trypanosoma cruzi appears to be interrupted in Chile; however, data show increasing incidence of Chagas' disease, raising concerns that there may be a reemerging problem. OBJECTIVE To estimate the actual risk in a changing world it is necessary to consider the historical vector distribution and correlate this distribution with the presence of cases and climate change. METHODS Potential distribution models of Triatoma infestans and Chagas disease were performed using Maxent, a machine-learning method. FINDINGS Climate change appears to play a major role in the reemergence of Chagas' disease and T. infestans in Chile. The distribution of both T. infestans and Chagas' disease correlated with maximum temperature, and the precipitation during the driest month. The overlap of Chagas' disease and T. infestans distribution areas was high. The distribution of T. infestans, under two global change scenarios, showed a minimal reduction tendency in suitable areas. MAIN CONCLUSION The impact of temperature and precipitation on the distribution of T. infestans, as shown by the models, indicates the need for aggressive control efforts; the current control measures, including T. infestans control campaigns, should be maintained with the same intensity as they have at present, avoiding sylvatic foci, intrusions, and recolonisation of human dwellings.

Complete Mitochondrial Genome of the Chagas Disease Vector, Triatoma rubrofasciata

Triatoma rubrofasciata is a wide-spread vector of Chagas disease in Americas. In this study, we completed the mitochondrial genome sequencing of T. rubrofasciata. The total length of T. rubrofasciata mitochondrial genome was 17,150 bp with the base composition of 40.4% A, 11.6% G, 29.4% T and 18.6% C. It included 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and one control region. We constructed a phylogenetic tree on the 13 protein-coding genes of T. rubrofasciata and other 13 closely related species to show their phylogenic relationship. The determination of T. rubrofasciata mitogenome would play an important role in understanding the genetic diversity and evolution of triatomine bugs.

El baúl de los recuerdos

El Dr. Salvador Mazza (Buenos Aires, Argentina, 6 de junio de 1886 - Monterrey, México, 9 de noviembre de 1946) fue un médico sanitarista y bacteriólogo argentino, que se destacó por haber dedicado casi toda su vida al estudio y a la lucha contra la tripanosomiasis americana (enfermedad de Chagas-Mazza) y otras enfermedades endémicas. Completó los estudios de Carlos Chagas sobre el agente etiológico (Trypanosoma cruzi) y sobre el vector de la enfermedad, la vinchuca (Triatoma infestans), además de perfeccionar el tratamiento de la misma. La "Misión de Estudios de Patología Regional Argentina" (MEPRA) fue fundada por la Universidad de Buenos Aires (UBA) en 1926, instalándose en la Provincia de Jujuy, el 25 de Agosto de 1929, en ella se escribieron 551 publicaciones, siendo 482 realizadas por Salvador Mazza. Durante 20 años, la MEPRA fue el centro científico más importante de la República Argentina, hasta que en 1946 fue trasladada a Buenos Aires, siendo el mismo año del fallecimiento de su fundador; estos dos hechos históricos fueron nefastos para la institución, que fue conducida posteriormente sin la dinámica de Don Salvador hasta su desaparición en 1959. En la sede de la MEPRA, se halló un baúl de cuero, repleto de fotografías viejas, más de 4.800 en las que se vislumbraba, el trabajo de Don Salvador durante su incansable tarea en el norte argentino; este baúl de los recuerdos fue rescatado, ordenado, clasificado y posteriormente digitalizado por la Universidad Nacional de Jujuy (UNJu) y depositado bajo la custodia del Archivo Histórico de la Provincia de Jujuy.

The trunk of memories Dr. Salvador Mazza (Buenos Aires, Argentina, June 6, 1886 - Monterrey, Mexico, November 9, 1946) was an Argentine sanitarist and bacteriologist, who stood out for having spent most of his life studying and fighting against american trypanosomiasis (Chagas-Mazza' disease) and other endemic diseases. He completed the studies of Carlos Chagas on the etiological agent (Trypanosoma cruzi) and on the vector of the disease, vinchuca (Triatoma infestans), besides perfecting the treatment of it. The "Mission of Studies of Regional Pathology in Argentina" (MEPRA) was founded by the University of Buenos Aires (UBA) in 1926 and settled in the province of Jujuy on August 25, 1929; 551 publications were written, 482 made by Salvador Mazza. During 20 years, the MEPRA was the most important scientific center of the Argentine Republic, until in 1946 it was transferred to Buenos Aires, being the same year of the death of its founder; these two historical events were harmful to the institution, which was later conducted without the dynamics of Don Salvador until his disappearance in 1959. In the headquarters of the MEPRA, a leather trunk was found, full of old photographs, more than 4,800 in which it was glimpsed, the work of Don Salvador during his tireless work in the Argentine north; this trunk of memories was rescued, sorted, classified and later digitized by the National University of Jujuy (UNJu) and deposited under the custody of the Historical Archive of the Province of Jujuy.

O baú de memórias O Dr. Salvador Mazza (Buenos Aires, Argentina, 6 de junho, 1886 - Monterrey, México, 09 de novembro de 1946) foi um médico e sanitarista bacteriologista argentino, que se destacou por ter dedicado a sua vida ao estudo eà luta contra a tripanossomíase americana (doença de Chagas) e outras doenças endêmicas. Completou os estudos de Carlos Chagas sobre o agente etiológico (Trypanosoma cruzi) e o barbeiro, vector da doença, o "vinchuca" (Triatoma infestans), além de melhorar o tratamento dos mesmos. A "Missão de Estudo da Patologia Regional Argentina" (MEPRA) foi fundada pela Universidade de Buenos Aires (UBA), em 1926, estabelecendo-se na província de Jujuy, em 25 de agosto de 1929, em suas foram escritas 551 publicações, sendo 482 feita por Salvador Mazza. Durante 20 anos, a MEPRA foi o mais importante centro científico da Argentina, até que em 1946 foi transferido para Buenos Aires, sendo o ano da morte de seu fundador; estes dois acontecimentos históricos foram desastrosos para a instituição, que foi conduzida mais tarde, sem a dinâmica de Don Salvador até seu desaparecimento em 1959. Na sede do MEPRA foi encontrado um baú de couro, cheio de fotografias antigas, mais de 4.800 apareceu em que assomava a obra de Don Salvador por seu trabalho incansável no norte da Argentina; este baú de memórias foi resgatado, classificado e após digitalizado pela Universidade Nacional de Jujuy (UNJU) e depositado sob a custódia do Arquivo Histórico da Província de Jujuy.

Chagas disease ecoepidemiology and environmental changes in northern Minas Gerais state, Brazil

BACKGROUND Triatoma sordida and Triatoma pseudomaculata are frequently captured triatomine species in the Brazilian savannah and caatinga biomes, respectively, and in Brazilian domiciles. OBJECTIVES This study identified eco-epidemiological changes in Chagas disease in northern Minas Gerais state, Brazil, and considered the influence of environmental shifts and both natural and anthropogenic effects. METHODS Domicile infestation and Trypanosoma cruzi infection rates were obtained from triatomines and sylvatic reservoirs during the following two time periods: the 1980s and 2007/2008. Entomological and climatic data with land cover classification derived from satellite imagery were integrated into a geographic information system (GIS), which was applied for atmospheric correction, segmentation, image classification, and mapping and to analyse data obtained in the field. Climatic data were analysed and compared to land cover classifications. RESULTS A comparison of current data with data obtained in the 1980's showed that T. sordida colonised domiciliary areas in both periods, and that T. pseudomaculata did not colonise these areas. There was a tendency toward a reduction in T. cruzi infection rates in sylvatic reservoirs, and of triatomines captured in both households and in the sylvatic environment. T. sordida populations have reduced in the sylvatic environment, while T. pseudomaculata showed an expanding trend in the region compared to counts observed in the 1980's in the sylvatic environment. This may be related to high deforestation rates as well as gradual increases in land surface temperature (LST) and temperatures along the years. MAIN CONCLUSIONS Our results suggest a geographical expansion of species into new biomes as a result of anthropogenic and climatic changes that directly interfere with the reproductive and infection processes of vectors.

The eco-epidemiology of Triatoma infestans in the temperate Monte Desert ecoregion of mid-western Argentina

BACKGROUND The eco-epidemiological status of Chagas disease in the Monte Desert ecoregion of western Argentina is largely unknown. We investigated the environmental and socio-demographic determinants of house infestation with Triatoma infestans, bug abundance, vector infection with Trypanosoma cruzi and host-feeding sources in a well-defined rural area of Lavalle Department in the Mendoza province. METHODS Technical personnel inspected 198 houses for evidence of infestation with T. infestans, and the 76 houses included in the current study were re-inspected. In parallel with the vector survey, an environmental and socio-demographic survey was also conducted. Univariate risk factor analysis for domiciliary infestation was carried out using Firth penalised logistic regression. We fitted generalised linear models for house infestation and bug abundance. Blood meals were tested with a direct ELISA assay, and T. cruzi infection was determined using a hot-start polymerase chain reaction (PCR) targeting the kinetoplast minicircle (kDNA-PCR). FINDINGS The households studied included an aged population living in precarious houses whose main economic activities included goat husbandry. T. infestans was found in 21.2% of 198 houses and in 55.3% of the 76 re-inspected houses. Peridomestic habitats exhibited higher infestation rates and bug abundances than did domiciles, and goat corrals showed high levels of infestation. The main host-feeding sources were goats. Vector infection was present in 10.2% of domiciles and 3.2% of peridomiciles. Generalised linear models showed that peridomestic infestation was positively and significantly associated with the presence of mud walls and the abundance of chickens and goats, and bug abundance increased with the number of all hosts except rabbits. MAIN CONCLUSIONS We highlight the relative importance of specific peridomestic structures (i.e., goat corrals and chicken coops) associated with construction materials and host abundance as sources of persistent bug infestation driving domestic colonisation. Environmental management strategies framed in a community-based programme combined with improved insecticide spraying and sustained vector surveillance are needed to effectively suppress local T. infestans populations.