Temporal assessment of entomological surveillance of Trypanosoma cruzi vectors in an endemic area of northeastern Brazil.

Entomological surveillance is essential for the control of triatomines and the prevention of Trypanosoma cruzi infection in humans and domestic animals. Thus, the objective of this study was to evaluate entomological indicators and triatomine control during the period from 2005 to 2015 in an endemic area in the state of Rio Grande do Norte, Brazil. This observational and retrospective study was developed based on data analysis related to active entomological surveillance activities and chemical control of infested housing units (HU) in the Agreste mesoregion of the state of Rio Grande do Norte, Brazil, in the period between 2005 to 2015. The quantitative analysis of housing units surveyed for entomological indicators was performed by linear regression of random effects (p < 0.05). The effect of the number of HU surveyed on the entomological indicators was analyzed by fitting a linear random effects regression model and an increasing intradomiciliary colonization rate was significant. In the period evaluated 92,156 housing units were investigated and the presence of triatomines was reported in 4,639 (5.0%). A total of 4,653 specimens of triatomines were captured and the species recorded were Triatoma pseudomaculata (n = 1,775), Triatoma brasiliensis (n = 1,569), Rhodnius nasutus (n = 741) and Panstrongylus lutzi (n = 568), with an index of natural infection by T. cruzi of 2.2%. Only 53.1% of the infested HU were subjected to chemical control. Moreover, there was a decrease in the total number of HU surveyed over time associated with an increase in the index of intradomiciliary colonization (p = 0.004). These data demonstrated that entomological surveillance and control of vectors in the Agreste mesoregion of the state has been discontinued, emphasizing the need for more effective public policies to effectively control the vectors, in order to avoid the exposure of humans and domestic animals to the risk of T. cruzi infection.

Triatomine and Trypanosoma cruzi discrete typing units distribution in a semi-arid area of northeastern Brazil.

The occurrence of triatomine species, their bloodmeal sources and the discrete typing units (DTUs) of Trypanosoma cruzi isolated from them were determined in different municipalities of the state of Rio Grande do Norte, Brazil. Triatomine captures were carried out in the rural areas of 23 municipalities. The genotyping of T. cruzi isolates was performed using the mitochondrial cytochrome c oxidase subunit 2 (coii) gene, the D7 region of the 24Sα rDNA, and the spliced leader intergenic region (SL-IR). Five triatomine species were captured, and the most frequent was Triatoma brasiliensis (84.3%; 916/1086), which was found in 16 of the 23 municipalities surveyed, and infested all types of environment investigated. The TcI DTU was found in all mesoregions surveyed in 51.5% (17/33) of the culture-positive samples. In contrast, TcII (9.1%; 3/33) was detected in the Central mesoregion, while TcIII (27.3%; 9/33) was found in all mesoregions. The geographic distribution and spatial overlap of different DTUs was inferred using the superposition of the radius of occurrence of isolates and using ecological niche distribution modelling. Triatoma brasiliensis was found infected in all mesoregions and with all three T. cruzi DTUs, including mixed infections. With regard to bloodmeal sources, the DNA of rodents was found in triatomines infected with either TcI or TcIII, while that of domestic animals and humans was associated with both single and mixed infections. Our findings demonstrate that different DTUs of T. cruzi are widely dispersed among triatomines in our study area. The association of T. brasiliensis with several different mammalian hosts, as well as overlapping areas with different DTUs, suggests that this triatomine species may have an important role as a vector in both anthropic and sylvatic environments.

Synanthropic triatomines (Hemiptera: Reduviidae): infestation, colonization, and natural infection by trypanosomatids in the State of Rio Grande do Norte, Brazil.

INTRODUCTION: The ecoepidemiological situation in the State of Rio Grande do Norte, Brazil is characterized by frequent invasion and colonization of domiciliary units (DUs) by several triatomine species, with high rates of natural infection by Trypanosoma cruzi. METHODS: We evaluated the possibility of vector transmission of T. cruzi based on records of the occurrence of domiciled triatomines collected by the Secretariat of State for Public Health from 2005 to 2015. During this period, 67.7% (113/167) of municipalities conducted at least one active search and 110 recorded the presence of insects in DUs. These activities were more frequent in municipalities considered to have a high and medium-level risk of T. cruzi transmission. RESULTS: Of 51,569 captured triatomines, the most common species were Triatoma brasiliensis (47.2%) and T. pseudomaculata (40.2%). Colonies of T. brasiliensis, T. pseudomaculata, T. petrocchiae, Panstrongylus lutzi, and Rhodnius nasutus were also recorded in the intradomicile and peridomicile. Natural infection by trypanosomatids was detected in 1,153 specimens; the highest rate was found in R. nasutus (3.5%), followed by T. brasiliensis (2.5%) and T. pseudomaculata (2.4%). There have been high levels of colonization over the years; however, not all infested DUs have been sprayed. CONCLUSIONS: This is the first report of intradomicile and peridomicile colonization by P. lutzi. These results demonstrate the risk of new cases of infection by T. cruzi and reinforce the need for continuous entomological surveillance in the State of Rio Grande do Norte.

Synanthropic triatomines (hemiptera: reduviidae): infestation, colonization, and natural infection by trypanosomatids in the state of Rio Grande do Norte, Brazil

Abstract INTRODUCTION The ecoepidemiological situation in the State of Rio Grande do Norte, Brazil is characterized by frequent invasion and colonization of domiciliary units (DUs) by several triatomine species, with high rates of natural infection by Trypanosoma cruzi. METHODS: We evaluated the possibility of vector transmission of T. cruzi based on records of the occurrence of domiciled triatomines collected by the Secretariat of State for Public Health from 2005 to 2015. During this period, 67.7% (113/167) of municipalities conducted at least one active search and 110 recorded the presence of insects in DUs. These activities were more frequent in municipalities considered to have a high and medium-level risk of T. cruzi transmission. RESULTS Of 51,569 captured triatomines, the most common species were Triatoma brasiliensis (47.2%) and T. pseudomaculata (40.2%). Colonies of T. brasiliensis, T. pseudomaculata, T. petrocchiae, Panstrongylus lutzi, and Rhodnius nasutus were also recorded in the intradomicile and peridomicile. Natural infection by trypanosomatids was detected in 1,153 specimens; the highest rate was found in R. nasutus (3.5%), followed by T. brasiliensis (2.5%) and T. pseudomaculata (2.4%). There have been high levels of colonization over the years; however, not all infested DUs have been sprayed. CONCLUSIONS: This is the first report of intradomicile and peridomicile colonization by P. lutzi. These results demonstrate the risk of new cases of infection by T. cruzi and reinforce the need for continuous entomological surveillance in the State of Rio Grande do Norte.

[Investigation of an outbreak of acute Chagas disease outside the Amazon Region, in Rio Grande do Norte State, Brazil, 2016]. / Investigação de surto de doença de Chagas aguda na região extra-amazônica, Rio Grande do Norte, Brasil, 2016.

The aim of this article was to confirm and describe an outbreak of acute Chagas disease involving oral transmission in the western region of Rio Grande do Norte State, Brazil. This was a descriptive case series study in which the data sources were medical records and interviews with suspected cases from September 16 to November 19, 2015. An entomological investigation was conducted in the probable sites of infection for acute Chagas disease cases. Eighteen cases of acute Chagas disease were confirmed in residents of four municipalities (counties) in Rio Grande do Norte State. The most frequently reported signs and symptoms were fever and weakness (n = 18), followed by myalgia (n = 17), prostration, loss of appetite, and edema of the lower limbs (n = 15). Median duration of fever was 20 days (range: 6 to 45 days). Fifteen cases were confirmed by the laboratory criterion and three by epidemiological link with consistent clinical characteristics. All confirmed cases reported having consumed sugar cane juice from the same mill. A total of 110 triatomines were captured on the plantation where the sugar cane had been crushed for juice. The insects were found in the peridomicile, in stacks of firewood and close to the sugar cane mill. The majority of the captured specimens were Triatoma brasiliensis and showed a natural infection rate of 63%. The Chagas disease outbreak was confirmed with oral transmission via ingestion of sugar cane juice contaminated with infected triatomines, as evidenced by the epidemiological link between the investigated cases and the entomological survey in the probable site where the infection occurred.

O objetivo do artigo foi confirmar e descrever um surto da doença de Chagas aguda por transmissão oral na mesorregião Oeste Potiguar, Rio Grande do Norte, Brasil. Trata-se de um estudo descritivo do tipo série de casos, tendo como fonte de dados os registros de atendimentos médicos e entrevistas com os casos suspeitos entre 16 de setembro e 19 de novembro de 2015. Realizou-se pesquisa entomológica nas prováveis localidades de infecção dos casos de doença de Chagas aguda. Foram confirmados 18 casos de doença de Chagas aguda em residentes de quatro municípios do Rio Grande do Norte. Os sinais e sintomas mais relatados foram febre e fraqueza (n = 18), seguidos de mialgia (n = 17), prostração, inapetência e edema de membros inferiores (n = 15). A mediana de duração da febre foi de 20 dias (intervalo: 6 a 45 dias). Quinze casos foram confirmados por critério laboratorial e três por vínculo epidemiológico com clínica compatível. Todos os casos confirmados relataram ter consumido caldo de cana da mesma procedência. Foram capturados 110 triatomíneos na fazenda onde ocorreu a moagem da cana consumida. Os insetos estavam no peridomicílio, em amontoados de lenha e próximos ao engenho. A maioria dos exemplares capturados era da espécie Triatoma brasiliensis, e apresentou um índice de infecção natural de 63%. Foi confirmado surto da doença de Chagas de transmissão oral por ingestão de caldo de cana contaminado por triatomíneo infectado, evidenciado pelo vínculo epidemiológico entre os casos investigados e a pesquisa entomológica no local provável de infecção.

El objetivo de este artículo fue confirmar y describir un brote de la enfermedad de Chagas aguda por transmisión oral en la mesorregión oeste de Rio Grande do Norte, Brasil. Se trata de un estudio descriptivo del tipo serie de casos, contando como fuente de datos los registros de atención médica y entrevistas en los casos sospechosos entre el 16 de septiembre y el 19 de noviembre de 2015. Se realizó una investigación entomológica en las probables localidades de infección de los casos de enfermedad de Chagas aguda. Fueron confirmados 18 casos de enfermedad de Chagas aguda en residentes de cuatro municipios de Rio Grande do Norte. Los signos y síntomas más informados fueron fiebre y debilidad (n = 18), seguidos de mialgia (n = 17), postración, inapetencia y edema de miembros inferiores (n = 15). La media de duración de la fiebre fue de 20 días (intervalo: 6 a 45 días). Quince casos fueron confirmados por criterio de laboratorio y tres por vínculo epidemiológico con clínica compatible. Todos los casos confirmados informaron haber consumido caldo de caña de la misma procedencia. Fueron capturados 110 triatominos en la hacienda donde se produjo la molienda de la caña consumida. Los insectos estaban en el peridomicilio, en montones de leña y cerca del ingenio azucarero. La mayoría de los ejemplares capturados era de la especie Triatoma brasiliensis, y presentó un índice de infección natural de un 63%. Se confirmó un brote de la enfermedad de Chagas de transmisión oral por ingestión de caldo de caña contaminado por triatomino infectado, evidenciado por el vínculo epidemiológico entre los casos investigados y la investigación entomológica en el lugar probable de infección.

Investigação de surto de doença de Chagas aguda na região extra-amazônica, Rio Grande do Norte, Brasil, 2016 / Investigation of an outbreak of acute Chagas disease outside the Amazon Region, in Rio Grande do Norte State, Brazil, 2016 / Investigación del brote de la enfermedad de Chagas aguda en la región extra-amazónica, Rio Grande do Norte, Brasil, 2016

Resumo: O objetivo do artigo foi confirmar e descrever um surto da doença de Chagas aguda por transmissão oral na mesorregião Oeste Potiguar, Rio Grande do Norte, Brasil. Trata-se de um estudo descritivo do tipo série de casos, tendo como fonte de dados os registros de atendimentos médicos e entrevistas com os casos suspeitos entre 16 de setembro e 19 de novembro de 2015. Realizou-se pesquisa entomológica nas prováveis localidades de infecção dos casos de doença de Chagas aguda. Foram confirmados 18 casos de doença de Chagas aguda em residentes de quatro municípios do Rio Grande do Norte. Os sinais e sintomas mais relatados foram febre e fraqueza (n = 18), seguidos de mialgia (n = 17), prostração, inapetência e edema de membros inferiores (n = 15). A mediana de duração da febre foi de 20 dias (intervalo: 6 a 45 dias). Quinze casos foram confirmados por critério laboratorial e três por vínculo epidemiológico com clínica compatível. Todos os casos confirmados relataram ter consumido caldo de cana da mesma procedência. Foram capturados 110 triatomíneos na fazenda onde ocorreu a moagem da cana consumida. Os insetos estavam no peridomicílio, em amontoados de lenha e próximos ao engenho. A maioria dos exemplares capturados era da espécie Triatoma brasiliensis, e apresentou um índice de infecção natural de 63%. Foi confirmado surto da doença de Chagas de transmissão oral por ingestão de caldo de cana contaminado por triatomíneo infectado, evidenciado pelo vínculo epidemiológico entre os casos investigados e a pesquisa entomológica no local provável de infecção.

Abstract: The aim of this article was to confirm and describe an outbreak of acute Chagas disease involving oral transmission in the western region of Rio Grande do Norte State, Brazil. This was a descriptive case series study in which the data sources were medical records and interviews with suspected cases from September 16 to November 19, 2015. An entomological investigation was conducted in the probable sites of infection for acute Chagas disease cases. Eighteen cases of acute Chagas disease were confirmed in residents of four municipalities (counties) in Rio Grande do Norte State. The most frequently reported signs and symptoms were fever and weakness (n = 18), followed by myalgia (n = 17), prostration, loss of appetite, and edema of the lower limbs (n = 15). Median duration of fever was 20 days (range: 6 to 45 days). Fifteen cases were confirmed by the laboratory criterion and three by epidemiological link with consistent clinical characteristics. All confirmed cases reported having consumed sugar cane juice from the same mill. A total of 110 triatomines were captured on the plantation where the sugar cane had been crushed for juice. The insects were found in the peridomicile, in stacks of firewood and close to the sugar cane mill. The majority of the captured specimens were Triatoma brasiliensis and showed a natural infection rate of 63%. The Chagas disease outbreak was confirmed with oral transmission via ingestion of sugar cane juice contaminated with infected triatomines, as evidenced by the epidemiological link between the investigated cases and the entomological survey in the probable site where the infection occurred.

Resumen: El objetivo de este artículo fue confirmar y describir un brote de la enfermedad de Chagas aguda por transmisión oral en la mesorregión oeste de Rio Grande do Norte, Brasil. Se trata de un estudio descriptivo del tipo serie de casos, contando como fuente de datos los registros de atención médica y entrevistas en los casos sospechosos entre el 16 de septiembre y el 19 de noviembre de 2015. Se realizó una investigación entomológica en las probables localidades de infección de los casos de enfermedad de Chagas aguda. Fueron confirmados 18 casos de enfermedad de Chagas aguda en residentes de cuatro municipios de Rio Grande do Norte. Los signos y síntomas más informados fueron fiebre y debilidad (n = 18), seguidos de mialgia (n = 17), postración, inapetencia y edema de miembros inferiores (n = 15). La media de duración de la fiebre fue de 20 días (intervalo: 6 a 45 días). Quince casos fueron confirmados por criterio de laboratorio y tres por vínculo epidemiológico con clínica compatible. Todos los casos confirmados informaron haber consumido caldo de caña de la misma procedencia. Fueron capturados 110 triatominos en la hacienda donde se produjo la molienda de la caña consumida. Los insectos estaban en el peridomicilio, en montones de leña y cerca del ingenio azucarero. La mayoría de los ejemplares capturados era de la especie Triatoma brasiliensis, y presentó un índice de infección natural de un 63%. Se confirmó un brote de la enfermedad de Chagas de transmisión oral por ingestión de caldo de caña contaminado por triatomino infectado, evidenciado por el vínculo epidemiológico entre los casos investigados y la investigación entomológica en el lugar probable de infección.