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.

Conhecimentos sobre a doença de Chagas entre escolares de dois municípios de Minas Gerais, Brasil / Knowledge about Chagas disease among schoolchildren from two municipalities of Minas Gerais, Brazil

Resumo Introdução: No Brasil, a vigilância entomológica da doença de Chagas (DCh) é respaldada na participação comunitária, que notifica a presença dos vetores nas habitações. Assim, a sustentabilidade desta medida de controle depende do conhecimento da população sobre os vetores. Objetivo: Avaliar o conhecimento de escolares sobre a doença de Chagas nos municípios mineiros de Itatiaiuçu (vigilância ativa) e Sabará (vigilância inativa). Método: Questionário semiestruturado foi aplicado para alunos matriculados no ensino médio em duas escolas de Sabará (rural e urbana) e uma em Itatiaiuçu (urbana). Resultados: Em geral, os alunos residentes em Sabará demonstraram conhecimento limitado acerca dos vetores, patógeno, transmissão e doença (sem diferenças relevantes quanto à localização entre área urbana e rural), quando comparados aos residentes em Itatiaiuçu, que apesar de ter uma vigilância mais atuante, também não apresentaram conhecimento totalmente satisfatório. Conclusões: Os resultados enfatizam a carência de informações sobre a DCh tanto em relação ao conhecimento acadêmico quanto às campanhas de educação firmadas pelo programa. Ações educativas para sensibilizar a comunidade e promover o conhecimento sobre esta doença mostram-se necessárias e fundamentais para a manutenção da vigilância ao longo do tempo e espaço.

Abstract Background: In Brazil, entomological surveillance of Chagas disease (ChD) is based on community participation, which notifies the presence of vectors inside their homes. Thus, the sustainability of this control measure depends on the knowledge of the population about the vectors. Objective: To evaluate the knowledge of schoolchildren about ChD in the municipalities of Itatiaiuçu (active surveillance) and Sabará (inactive surveillance). Method: A semi-structured questionnaire was given to students enrolled in two high schools in Sabará (rural and urban) and one in Itatiaiuçu (urban). Results: In general, students living in Sabará demonstrated only limited knowledge about vectors, pathogens, transmission, and disease (with no significant differences between the schools in urban and rural areas). Similarly, the schoolchildren in Itatiaiuçu, despite living in an area of active surveillance, also did not have a fully satisfactory knowledge of ChD. Conclusions: The results emphasize the lack of information about ChD, both in relation to academic knowledge and the education campaigns established by the program. Improvements in educational interventions to raise community awareness and promote knowledge about ChD are necessary and vital for maintaining vigilance against ChD over space and time.

Massive invasion on a Triatominae insectarium (Hemiptera: Heteroptera: Reduviidae) by Attagenus fasciatus (Thunberg, 1795) (Coleoptera: Dermestidae: Attageninae)

ABSTRACT Background: Triatominae are vectors of the protozoan Trypanosoma cruzi, the causative agent of Chagas disease. This study aims to report an infestation on Triatominae colonies by a beetle, previously identified as a pest. Methods: The management of these colonies should be improved to maximize their usefulness, and factors that may cause harm to them should be avoided as much as possible. Results: This is the first report on a coleopteran infestation on living Triatominae colonies worldwide. Conclusions: The present record provides an important warning to researchers who maintain insectaries in general, especially those who rear triatomines, to carry protective measures against such invasions.

Occurrence of triatomines in public spaces: An atypical case in the Southwestern Brazilian Amazon

ABSTRACT Background: Triatomines infest atypical public spaces in the Western Amazon. Methods: Frequent visitors to these spaces captured the insects in the state of Acre, Brazil (Rio Branco and Cruzeiro do Sul). Results: Six insects were found in a penitentiary, a church, a school, a university, a hospital, and a health center. Five of the insects were adults (three positive for Trypanosoma cruzi) and one was a nymph. Conclusions: This is the first report of triatomine occurrence in schools or churches. These data are important for implementing surveillance strategies and alerting individuals about possible changes in Chagas disease transmission dynamics.

Population size regulation is density-dependent in Rhodnius prolixus (Hemiptera: Reduviidae) through an irritability mechanism

BACKGROUND Physical factors can determine the level of triatomine abundance, but do not regulate their population densities, and neither do natural enemies. OBJECTIVES To identify the processes associated with density-dependent triatomine population regulation. METHODS We set-up a laboratory experiment with four interconnected boxes; the central box harbored Rhodnius prolixus bugs and one hamster. Stage 5 and adult densities of 10, 20, 30, 40, and 60 bugs per hamster, were replicated four times (except the density of 60 bugs). Hamster's irritability and several triatomine responses were measured: feeding, development time and longevity, mortality, fecundity, dispersal, and the net reproductive value (R o ). FINDINGS Density had a statistically significant effect on irritability, but not on the percent of bugs feeding. Density was significant on blood meal size ingested in bugs that did not move between boxes, but not significant when the bugs moved. Density and irritability affected the proportion of stage 5 nymphs molting, and the proportion of adult bugs dying per day and over a three-week period. There was a highly significant effect of density and irritability on R o . MAIN CONCLUSIONS We showed that a density-dependent mechanism, acting through the irritability of the host, seems the most plausible process regulating populations in triatomines.

Triatoma rubrovaria (Hemiptera, Reduviidae, Triatominae) in the Pampa biome, Brazil: a retrospective study of its occurrence and abundance

ABSTRACT Triatoma rubrovaria has been captured in some areas of Rio Grande do Sul State (RS), Brazil, as this species can be found in the Pampa biome. Its distribution across this biome should be described in detail to verify the potential of this vector to transmit Trypanosoma cruzi. This study aimed to investigate the occurrence of T. rubrovaria in the Pampa biome and transitional areas of RS. The collected information resulted from the analysis of secondary data provided by the Centro Estadual de Vigilancia em Saude (CEVS - State's Center of Health Surveillance). The following aspects were taken into consideration: the year in which the insect was captured, the city, the number of specimens captured, invasion or domiciliation, the notification in the household, surroundings or both, and T. cruzi infection. The data comprised the period from 2009 to 2020, in 109 cities located in the Pampa biome and 98 located in transitional areas. The Pampa biome exhibited 85% of the occurrences of T. rubrovaria, while 1.2% of specimens were T. cruzi-like positive. Both the first and second biennia concentrated 64.6% of captures. Alegrete city, Cangucu city and Piratini city were the locations in the Pampa where the largest numbers of specimens were found. Regarding the transitional areas, Roque Gonzales city, Santiago city and Santana da Boa Vista city exhibited the largest numbers. Most insects were adults, which were found in households. Even though positivity for T. cruzi-like was low, the species still has epidemiological importance in the region.

Monitoring Rhodnius neglectus (Lent, 1954) populations' susceptibility to insecticide used in controlling actions in urban areas northwest of São Paulo state

ABSTRACT Background: Chagas disease (CD) is caused by the flagellate protozoan Trypanosoma cruzi and can be carried by different species of triatomines, including Rhodnius neglectus, which is wild, well distributed in Brazil, and has formed colonies in palm trees located in urban areas of municipalities in the state of São Paulo. Chemical control has been routinely used to reduce population density, but each year, there has been an increase in species dispersion and density. This study aimed to evaluate the susceptibility of insects to insecticides used in control. Methods: The reference population was collected from Araçatuba municipality, Nilce Maia. Dilutions of deltamethrin were prepared and applied to the back of the first-stage nymphs, which were biologically synchronized. The control group received pure acetone only. Mortality was assessed after 72 h. Results: The mortality rate with respect to diagnostic dose was 100%. The susceptibility profile observed for this population showed RR50 ranging from 1.76 to 3.632. Conclusions: The populations were susceptible to the insecticides tested. It is possible that the insecticide residual effect on this ecotope has decreased the lifespan, and controlling failures may be the cause of recolonization in this environment.

Initial report of Panstrongylus rufotuberculatus (Champion, 1899) Triatominae (Hemiptera: Reduviidae) in Roraima, western Amazon state, Brazil

ABSTRACT Background: This study is the first report of the species Panstrongylus rufotuberculatus in Roraima, a state in northern Brazil. Methods: We collected specimens from a residence in the municipality of Rorainópolis. Results: Our findings confirmed the occurrence of this species in Roraima, increasing the number of registered species from six to seven. Conclusions: Future studies are required to further investigate and expand our knowledge of the occurrence of this species and its epidemiological importance for this state.

Triatomine fauna in the state of Bahia, Brazil: What changed after 40 years of the vector-control program?

ABSTRACT Background: Neglected tropical diseases are a growing threat to global health, and endemic Chagas disease has emerged as one of the most important health problems in America. The main strategy to prevent Trypanosoma cruzi transmission is chemical control of vectors. This study presents a descriptive analysis of synanthropic triatomines before and after the implementation of a vector-control program in Bahia, Brazil. Methods: Descriptive analysis and geospatial statistics were performed on triatomine data, (1) the relative abundance and (2) proportional spatial distribution, from Bahia during two periods: (A) 1957 to 1971 and (B) 2006 to 2019. Results: We observed a decrease in the relative abundance of Panstrongylus megistus (A: n=22.032, 61.9%; B: n=1.842, 1.0%) and Triatoma infestans (A: n=1.310, 3.7%; B: n=763, 0.43%), as well as an increase in the relative abundance of T. sordida (A: n=8.314, 23.4%, B: n=146.901, 81.6%) and T. pseudomaculata (A: n=894, 2.5%, B: n=16.717, 9.3%). Conclusions: Our results indicate a clear reduction in the occurrence of P. megistus and T. infestans (last record in 2015) and an increase in the relative abundance and geographical distribution of T. sordida and T. pseudomaculata after 40 years of the vector-control program. The high frequency of other triatomine species in the municipalities of the state of Bahia and their abundance in recent years highlight the need to reinforce permanent entomological surveillance actions to prevent Chagas disease.

Actualización de la distribución geográfica de triatominos en el departamento del Putumayo / Update to the geographical distribution of triatomines in the Department of Putumayo / Atualização da distribuição geográfica de triatomíneos no Departamento de Putumayo

La enfermedad de Chagas es una zoonosis producida por la infección del Trypanosoma cruzi (T. cruzi) (1), cuya principal vía de transmisión es vectorial (2). Esta enfermedad se caracteriza por ser una infección crónica que puede ocasionar daños cardiacos, digestivos y neurológicos irreversibles (3). En el departamento del Putumayo, de acuerdo con los datos del Sistema de Vigilancia Epidemiológica (SIVIGILA), entre el año 2015 y el 2020, se han notificado 19 casos de Chagas crónico y 4 casos de Chagas agudos (4). Por este motivo resulta de gran interés compartir con los lectores de la revista MedUNAB la actualización de la distribución geográfica de los triatominos, vectores de la enfermedad de Chagas, y establecer el riesgo epidemiológico que representan para la población Putumayense, donde hay hallazgos de gran importancia porque se identifican especies en municipios y localidades donde antes no se conocían. Palabras claves: Triatominae; Enfermedad de Chagas; Infección por Trypanosoma cruzi; Infecciones; Insectos Vectores; Colombia.

Chagas Disease is a zoonotic disease produced by infection with Trypanosoma cruzi (T. cruzi) (1), whose main route of transmission is vectorial (2). This disease is characterized by being a chronic infection that can cause irreversible cardiac, digestive, and neurological damage (3). In the department of Putumayo, according to data from the epidemiological surveillance system (SIVIGILA, for the Spanish original), between 2015 and 2020, 19 chronic cases and 4 acute cases of Chagas were reported (4). For this reason, it is important to share with the readers of the MedUNAB journal the update to the geographical distribution of triatomines, vectors of Chagas Disease, and to establish the epidemiological risk that they represent for the population of Putumayo, where there are findings of great importance as species are identified in municipalities and localities where they were not previously found. Keywords: Triatominae; Chagas Disease; Trypanosoma cruzi; Infections; Insect Vectors; Colombia.

A doença de Chagas é uma zoonose causada por infecção com Trypanosoma cruzi (T. cruzi) (1), cujo principal modo de transmissão é vetorial (2). Esta doença é uma infecção crônica que pode causar danos cardíacos, digestivos e neurológicos irreversíveis (3). No Departamento de Putumayo, de acordo com dados do Sistema de Vigilância Epidemiológica (SIVIGILA), entre 2015 e 2020, foram notificados 19 casos de Chagas crônica e quatro casos de Chagas aguda (4). Por esta razão, é de grande interesse compartilhar com os leitores da revista MedUNAB a atualização da distribuição geográfica dos triatomíneos, vetores da doença de Chagas, e estabelecer o risco epidemiológico que representam para a população de Putumayo, onde há descobertas de grande importância, pois são identificadas espécies em municípios e localidades onde antes eram desconhecidas. Palavras-chave: Triatominae; Doença de Chagas; Infecção por Trypanosoma cruzi; Infecções; Insetos Vetores; Colômbia.

Histology of folicular development of hybrids between Triatoma infestans Klug, 1864 and Triatoma platensis Neiva, 1913 (Hemiptera: Heteroptera) / HISTOLOGÍA DEL DESARROLLO FOLICULAR DE HÍBRIDOS ENTRE Triatoma infestans Klug, 1864 Y Triatoma platensis Neiva, 1913 (HEMIPTERA: HETEROPTERA)

ABSTRACT Triatoma infestans and Triatoma platensis are interfertile species that frequently share ecotopes and produce natural fertile hybrids. Interspecific crossing allows the production of more suitable hybrid genotypes capable of colonizing new habitats. Therefore, studies of reproductive aspects in hybrids are of great importance. In this sense, oogenesis, a process that involves the development of the oocyte and allows the formation of viable eggs, is a relevant aspect. In this study, histological aspects focused on the follicular development of experimental hybrids were characterized. To do this, the ovaries of35 hybrid females were removed, paraffin-embedded and stained with hematoxylin-eosin. The development of the follicular epithelium and the oocyte in the stages of previtellogenesis and vitellogenesis were characterized, finding that the oogenesis of the hybrid females is well defined producing viable eggs and that the changes occurred at the histological level resemble those registered in T. infestans.

RESUMEN Triatoma infestans y Triatoma platensis son especies interfértiles que en ocasiones comparten ecotopos y producen híbridos fértiles naturales. El cruzamiento interespecífico podría permitir la producción de genotipos híbridos capaces de colonizar nuevos hábitats. Por ello, los estudios de aspectos reproductivos sobre estos organismos son de gran importancia. En este sentido la oogénesis, proceso que implica el desarrollo del ovocito y permite la formación de huevos viables, es un aspecto relevante. En este estudio se caracterizaron aspectos histológicos enfocados en el desarrollo folicular de híbridos experimentales. Para ello, se extrajeron los ovarios de 35 hembras híbrido, se embebieron en parafina y colorearon con hematoxilina-eosina. Se caracterizó el desarrollo del epitelio folicular y del ovocito en las etapas de previtelogénesis y vitelogénesis, encontrándose que la oogénesis de las hembras híbrido se encuentra bien definida produciendo huevos viables y que los cambios ocurridos a nivel histológico se asemejan a los registrados en T. infestans.

Cambio climático y enfermedades transmitidas por vectores en Argentina / Climate change and vector-borne diseases in Argentina

Resumen Las enfermedades transmitidas por vectores (ETVs) continúan siendo un desafío para los esfuerzos de agencias de salud pública, ya que mantienen o están aumentando su impacto sobre la salud de las comunidades afectadas. La característica común de las ETVs es que la única manera de prevenir exito samente nuevas infecciones es evitar el contacto entre vectores y humanos. No existen vacunas y no existirán en un futuro previsible para las principales ETVs que afectan la salud pública en Argentina. Aunque las epide mias de dengue desde 2009 atrajeron la atención mediática, otras ETVs, tales como Chagas o leishmaniasis, afectan la salud pública en Argentina desde hace décadas. Sobre ellas, y otras que potencialmente podrían instalarse en el territorio nacional (West Nile, Lyme, etc) hay repetidas referencias mediáticas que explican su recrudecimiento por el cambio climático. El argumento se basa en que la "tropicalización" del clima en regiones templadas promueve la instalación de ETVs en áreas previamente no favorables para ellas. Aunque existen muchas evidencias de que el clima está cambiando, son pocas las evidencias de que sea el clima el principal factor que promueve el recrudecimiento de las ETVs en Argentina. En este artículo, se discute la situación de los vectores de enfermedades en Argentina (con énfasis en triatominos), su vinculación con el llamado cambio climático y las actividades de control de vectores implementados por agencias gubernamentales de salud pública.

Abstract Vector-borne diseases (VBDs) continue to pose a challenge to the efforts of public health agencies by increasing their impact on the health of the affected communities. The common feature of VBDs is that the only way of preventing them is by avoid ing the contact between vectors and humans. There are no vaccines, and they will not be available shortly as tools for prevention and control in Argentina. Although dengue outbreaks attracted the attention of mass media from 2009, other VBDs have been affecting public health in Argentina for many decades, as Chagas disease and leishmaniasis. Over these, and others that could potentially settle in the national territory (West Nile, Lyme, etc.), there are repeated mass media claims and political declarations justifying their increase because of climate changes. The argument asserts that the "tropicalization" of the climate in temperate regions promotes the instal lation of VBDs in areas previously unfavorable for them. Although much evidence exists showing that the climate is changing, there is very little evidence that the climate is the main factor promoting the increase of VBDs. In this article, the influence of the so-called climate change on the situation of disease vectors in Argentina (with emphasis on triatomines) and vector control activities implemented by governmental public health agencies are discussed.

Metaciclogénesis de Trypanosoma cruzi en Belminus ferroae (Reduviidae: Triatominae) y capacidad infectiva de las heces en condiciones de laboratorio / Metacyclogenesis of Trypanosoma cruzi in B. ferroae (Reduviidae: Triatominae) and feces infectivity under laboratory conditions

Resumen | Introducción. Belminus ferroae es un triatomino de comportamiento entomófago, sin embargo, puede alimentarse de vertebrados ocasionalmente. No se ha demostrado infección natural por Trypanosoma cruzi en esta especie, como tampoco la metaciclogénesis del parásito. Objetivo. Examinar la metaciclogénesis de T. cruzi en B. ferroae y la capacidad infectiva de las heces o sus contenidos intestinales en roedores. Materiales y métodos. Se analizaron las heces y la orina expulsadas espontáneamente por los insectos o mediante compresión abdominal o extracción del contenido intestinal a los 10, 20, 30, 40, 50 y 60 días. Se cuantificó la carga parasitaria de T. cruzi y sus formas evolutivas se identificaron con tinción de Giemsa. Asimismo, se evaluó en ratones albinos la capacidad infectiva de los tripomastigotes metacíclicos de T. cruzi obtenidos de las heces o contenidos intestinales de los especímenes infectados. Resultados. El análisis parasitológico reveló tres (15 %) insectos infectados con T.cruzi a los 30 (n=1), 40 (n=1) y 50 (n=1) días después de la infección con cargas parasitarias de hasta 1,62 x 105 tripanosomas/mm3 y porcentajes de metaciclogénesis entre el 3,5 y el 6,78 %. Conclusiones. Se demuestra por primera vez, en una especie del género Belminus, la metaciclogenésis de T. cruzi en condiciones de laboratorio y la capacidad infectiva de las heces para un huésped vertebrado.

Abstract | Introduction: Belminus ferroae is a triatominae with entomophagous behavior. However, it may occasionally feed on vertebrates. Currently, there is no evidence of natural infection with Trypanosoma cruzi or the occurrence of metacyclogenesis in this species. Objective: To test T. cruzi metacyclogenesis in B. ferroae and the infectivity of their feces or intestinal contents in rodents under laboratory conditions. Materials and methods: Twenty nymphs of B. ferroae were infected with an autochthonous strain of T. cruzi (M/HOM/VE/09/P6). Fecal and urine samples were collected from spontaneous droppings or by compressing the bugs' abdomens and, eventually, by removing their gut contents, and then examined at 10, 20, 30, 40, 50, and 60 days. We quantified T. cruzi parasitic load, as well as the evolutionary forms in feces, urine, and intestinal contents by Giemsa staining. Similarly, we evaluated the infectivity of T. cruzi metacyclic trypomastigotes in albino mice. Results: The parasitological analysis showed three insects (15%) infected with T. cruzi at 30 (n=1), 40 (n=1), and 50 (n=1) days post-infection. We observed parasitic loads of up to 1.62 x 105 trypanosomes/mm3 and metacyclogenesis percentages between 3.5% and 6.78%. Conclusions: This is the first time that T. cruzi metacyclogenesis is reported in a species of the genus Belminus under laboratory conditions and the infectivity of Belminus' feces is demonstrated on a vertebrate host.

The rediscovery of Rhodnius domesticus Neiva & Pinto, 1923 (Hemiptera: Reduviidae: Triatominae) in the state of Espírito Santo, Brazil

Abstract INTRODUCTION: Rhodnius domesticus Neiva & Pinto, 1923 is a rare sylvatic triatomine endemic to the Atlantic Forest, with one known record for Espírito Santo (ES), Brazil from 1969. We present here its rediscovery in ES, 42 years after its first record. METHODS: In January 2011, a triatomine specimen was collected from a rural area of the municipality of Santa Teresa, ES. RESULTS: We confirmed this as a new record of R. domesticus in the Baixo Caldeirão locality. CONCLUSIONS: This finding supports the possibility of a wild population of R. domesticus in the mountainous region of the Atlantic forest of ES.

Do the new triatomine species pose new challenges or strategies for monitoring Chagas disease? An overview from 1979-2021

Chagas disease persists as one of the most important, and yet most neglected, diseases in the world, and several changes in its epidemiological aspects have been recorded since its discovery. Currently, some of the most relevant changes are related to: (i) the reduction in the incidence of the endemic due to the control of the most important vectors, Triatoma infestans and Rhodnius prolixus, in many countries; (ii) the migration of human populations spreading cases of the disease throughout the world, from endemic to non-endemic areas, transforming Chagas disease into a global threat; and (iii) new acute cases and deaths caused by oral transmission, especially in the north of Brazil. Despite the reduction in the number of cases, new challenges need to be responded to, including monitoring and control activities aiming to prevent house infestation by the secondary vectors from occurring. In 1979, Lent & Wygodzinsky(1) published the most complete review of the subfamily Triatominae, encompassing 111 recognised species in the taxon. Forty-two years later, 46 new species and one subspecies have been described or revalidated. Here we summarise the new species and contextualise them regarding their ecology, epidemiologic importance, and the obstacles they pose to the control of Chagas disease around the world.

Surveillance of Chagas disease vectors in Ceará State, Northeastern Brazil / Vigilância dos vetores da Doença de Chagas no Estado do Ceará, Nordeste do Brasil

Objective: Describe the spatial distribution, temporal trend and the natural infection rates by Trypanosoma cruzi in triatomines captured in Ceará State, between 2003 and 2014. Methods: Chagas Disease Control Program data were used to describe triatomine species circulating, their distribution in the state, the capture places (intradomicile and peridomicile), and the rates of natural infection by T. cruzi, between 2003 and 2014. Results: During this period, 401,721 triatomines were captured in 89.1% of the municipalities of the State, belonging to the species Triatoma pseudomaculata (53.9%), Triatoma brasiliensis (40.5%), Rhodnius nasutus (1.9%), Panstrongylus megistus (1.5%), Panstrogylus lutzi (1.3%), Triatoma rubrofasciata (0.8%), Panstrongylus geniculatus (< 0.1%), and Triatoma petrochiae (< 0.1%). Most of the specimens were caught in peridomicile areas (83.0%), with emphasis on T. pseudomaculata and T. brasiliensis, while P. lutzi was predominant in the intradomicile. P. lutzi had the highest infection rate by T. cruzi (7.8%), while T. pseudomaculata (0.9%), T. brasiliensis (1.0%), and P. megistus (1.3%) had the lowest rates. Conclusions: The occurrence of an enzootic cycle of T. cruzi and the presence of synanthropic animals that provide a source of blood meals to triatomines increases the risk of its transmission to humans, requiring constant vigilance by the sanitary authorities.

Objetivo: Descrever a distribuição especial, tendência temporal e a as taxas de infecção natural por T. cruzi em triatomíneos capturados no Estado do Ceará, entre 2003 e 2014. Métodos: Dados do Programa de Controle da Doença de Chagas foram utilizados para descrever as espécies de triatomíneos circulantes, sua distribuição no Estado, os locais de captura (intradomicílio e peridomicílio) e as taxas de infecção natural por T. cruzi entre os anos de 2003 e 2014. Resultados: Durante este período, 401.721 triatomíneos foram capturados em 89,1% dos municípios do Estado, pertencendo às espécies Triatoma pseudomaculata (53,9%), T. brasiliensis (40,5%), Rhodnius nasutus (1,9%), Panstrongylus megistus (1,5%), P. lutzi (1,3%), T. rubrofasciata (0,8%), P. geniculatus (< 0,1%) e T. petrochiae (< 0,1%). A maioria dos espécimes foi capturada no peridomicílio (83,0%), com destaque para T. pseudomaculata e T. brasiliensis, enquanto P. lutzi foi predominante no intradomicílio. P. lutzi teve a maior taxa de infecção por T. cruzi (7,8%), enquanto T. pseudomaculata (0,9%), T. brasiliensis (1,0%) e P. megistus (1,3%) tiveram as menores taxas. Conclusões: A ocorrência de um ciclo enzoótico de T. cruzi e a presença de animais sinantrópicos que proporcionam uma fonte de alimentação sanguínea aos triatomíneos aumentam o risco de sua transmissão aos humanos, exigindo das autoridades sanitárias uma vigilância constante desses vetores

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.

Ocorrência de triatomíneos no Estado do Ceará, Brasil / Occurrence of triatomines in the state of Ceará, Brazil

Esta revisão integrativa tem como objetivo analisar as publicações científicas nos últimos doze anos sobre triatomíneos encontrados no Estado do Ceará. Para tal, nos bancos de dados da Biblioteca Virtual em Saúde (BVS) foi realizada uma busca com associação dos descritores "Doença de Chagas", "Triatomíneos" e "Brasil". Após aplicação dos critérios de inclusão, exclusão e da análise dos seus conteúdos, oito artigos realizados no Estado do Ceará foram selecionados para a análise do estudo. Algumas espécies de triatomíneos encontradas no Nordeste são de extrema importância epidemiológica para o homem, pois estão associadas com domicílios humanos. As espécies mais predominantes com maior importância epidemiológica, com distribuição ampla no Ceará e presente no ambiente peridoméstico foram: Triatoma brasiliensis, Triatoma pseudomaculata, Panstrogylus megistus, Panstrogylus lutzi e Rhodnius nasutus. Várias espécies de triatomíneos tem a capacidade de transmitir Trypanosoma cruzi e de se adaptar com o ambiente peridoméstico e doméstico tornando o homem mais suscetível a infecção, sendo assim necessário estratégias de vigilância e controle do vetor. (AU)

This integrative review aims to analyze the scientific publications in the last twelve years on triatomines found at Ceará State. For this, a search was performed in the Biblioteca Virtual em Saúde (BVS) databases with association of the descriptors "Chagas Disease", "Triatomines" and "Brazil". After applying the inclusion, exclusion criteria and analysis of their content, eight articles were selected for the analysis and discussion. Some species of triatomines found in the Northeast region are of extreme epidemiological importance since they are associated with human households. The most prevalent species with epidemiological importance due to their large distribution in Ceará and presence in the peridomestic environment are: Triatoma brasiliensis, Triatoma pseudomaculata, Panstrogylus megistus, Panstrogylus lutzi and Rhodnius nasutus. Several species of triatomines have the capacity to transmit T. cruzi and the ability to adapt to the peridomestic and domestic environment turning humans more susceptible to infection, thus requiring surveillance and vector control strategies. (AU)

Ocorrência de triatomíneos no Estado do Ceará, Brasil / Occurrence of triatomines in the state of Ceará, Brazil

Esta revisão integrativa tem como objetivo analisar as publicações científicas nos últimos doze anos sobre triatomíneos encontrados no Estado do Ceará. Para tal, nos bancos de dados da Biblioteca Virtual em Saúde (BVS) foi realizada uma busca com associação dos descritores “Doença de Chagas”, “Triatomíneos” e “Brasil”. Após aplicação dos critérios de inclusão, exclusão e da análise dos seus conteúdos, oito artigos realizados no Estado do Ceará foram selecionados para a análise do estudo. Algumas espécies de triatomíneos encontradas no Nordeste são de extrema importância epidemiológica para o homem, pois estão associadas com domicílios humanos. As espécies mais predominantes com maior importância epidemiológica, com distribuição ampla no Ceará e presente no ambiente peridoméstico foram: Triatoma brasiliensis, Triatoma pseudomaculata, Panstrogylus megistus, Panstrogylus lutzi e Rhodnius nasutus. Várias espécies de triatomíneos tem a capacidade de transmitir Trypanosoma cruzi e de se adaptar com o ambiente peridoméstico e doméstico tornando o homem mais suscetível a infecção, sendo assim necessário estratégias de vigilância e controle do vetor.

This integrative review aims to analyze the scientific publications in the last twelve years on triatomines found at Ceará State. For this, a search was performed in the Biblioteca Virtual em Saúde (BVS) databases with association of the descriptors “Chagas Disease”, “Triatomines” and “Brazil”. After applying the inclusion, exclusion criteria and analysis of their content, eight articles were selected for the analysis and discussion. Some species of triatomines found in the Northeast region are of extreme epidemiological importance since they are associated with human households. The most prevalent species with epidemiological importance due to their large distribution in Ceará and presence in the peridomestic environment are: Triatoma brasiliensis, Triatoma pseudomaculata, Panstrogylus megistus, Panstrogylus lutzi and Rhodnius nasutus. Several species of triatomines have the capacity to transmit T. cruzi and the ability to adapt to the peridomestic and domestic environment turning humans more susceptible to infection, thus requiring surveillance and vector control strategies.

Comparison of phenol-chloroform and a commercial deoxyribonucleic acid extraction kit for identification of bloodmeal sources from triatomines (Hemiptera: Reduviidae)

Abstract INTRODUCTION: Knowledge of triatomine bloodmeal sources is essential for understanding vector-host interactions in Trypanosoma cruzi transmission cycles. Expensive commercial deoxyribonucleic acid (DNA) extraction kits are widely used for bloodmeal identification. This study assessed the performance of an inexpensive phenol-chloroform DNA extraction protocol for identification of triatomine bloodmeal sources, comparing it with a commercially available kit. METHODS: Both methods were used to obtain DNA from the intestinal contents of Triatoma brasiliensis blood-fed on either Columba sp., Mus musculus, or Gallus gallus. Subsequently, the mitochondrial 12S ribosomal ribonucleic acid (rRNA) gene was amplified by polymerase chain reaction, sequenced, and compared with GenBank data. RESULTS: Twelve (80%) samples extracted with the commercial kit and four (26.7%) with phenol-chloroform were pure (according to the A260/A280 ratio). Samples extracted with phenol-chloroform, except for Columba sp. samples, had higher DNA concentration than those extracted with the commercial kit. Samples extracted using phenol-chloroform and blood-fed on G. gallus had significantly higher DNA concentration than those blood-fed on Columba sp. (p-value <0.001) and M. musculus (p-value <0.001). The 215-base-pair 12S rRNA fragment was amplified from all samples and produced reliable sequences, enabling the identification of the bloodmeal source, most of which showed identity and coverage above 95%. The phenol-chloroform method was much less expensive than the commercial kit but took considerably more time to perform. CONCLUSIONS: Our data showed that both DNA extraction methods produced reliable sequences enabling identification of triatomine bloodmeal sources but differed greatly in cost and time required.