Risk factors and spatial analysis for domiciliary infestation with the Chagas disease vector Triatoma venosa in Colombia.

Background: In Colombia, communities living in the Andean region are the most affected by Chagas disease due to the presence of the main vectors, the environmental and risk factors associated with house infestation. Triatoma venosa is classified as a secondary vector that is frequently found in the departments of Boyaca and Cundinamarca, but epidemiological information and its association with risk factors in domestic and peridomestic areas is unknown. The study aimed to evaluate housing and environmental characteristics associated with domestic and peridomestic infestation by T. venosa and a risk map was estimated. Methods: A cross-sectional study was conducted in municipalities of Boyaca and Cundinamarca, Colombia. From March to July 2015, triatomine infestation screening surveys were conducted in 155 households. Multivariate analysis was performed to evaluate associations with the infestation and ecological niche modeling was estimated using environmental variables. Results: No statistical association was found with any of the housing variables in the adjusted multivariate analysis. However, in raw relationship infestation was associated with bushes < 10 m (OR = 3; 95% CI: 1.3-7.3) and higher temperature p value < 0.05. The developed final risk map pointed to 12 municipalities with no previous report of the disease, which should be sampled for the presence of T. venosa. Conclusion: This study highlights the relationship between environmental factors and T. venosa in Colombia and the importance of modeling tools to improve mapping efforts. Additional studies are needed to verify the association with bushes and higher temperatures and to verify infestation in predicted risk area with no previous report of the species.

Sylvatic triatominae: a new challenge in vector control transmission.

Over the last 10 years, Uruguay, Chile and Brazil have been certified as being free from disease transmission by Triatoma infestans, the main domiciliated vector for Chagas disease in the Southern Cone countries. This demonstrates that programmes addressing the vector for the disease's transmission are effective. These programmes have resulted in a dramatic decrease in the incidence of Chagas disease in Latin America. Guatemala was certified a few months ago as being free from disease transmission by Rhodnius prolixus, the main domiciliated vector for Chagas disease in Central American countries. However, the main concern for different countries' current control programmes is the continuity and sustainability of future vector control actions. The prevalence and incidence figures for individuals infected by Trypanosoma cruzi in Mexico and Andean and Central American countries highlights the need for broadened strategies in the struggle against the disease and its vectors. A number of triatomine insects are parasite vectors, each with a different life history. Therefore, it is important that new vector control strategies be proposed, keeping in mind that some species are found in peridomiciliary areas and wild ecotopes. The only viable control strategy is to reduce human interactions with vector insects so that the re-infestation and re-colonisation of human habitats will not take place.

Sylvatic triatominae: a new challenge in vector control transmission

Over the last 10 years, Uruguay, Chile and Brazil have been certified as being free from disease transmission by Triatoma infestans, the main domiciliated vector for Chagas disease in the Southern Cone countries. This demonstrates that programmes addressing the vector for the disease's transmission are effective. These programmes have resulted in a dramatic decrease in the incidence of Chagas disease in Latin America. Guatemala was certified a few months ago as being free from disease transmission by Rhodnius prolixus, the main domiciliated vector for Chagas disease in Central American countries. However, the main concern for different countries' current control programmes is the continuity and sustainability of future vector control actions. The prevalence and incidence figures for individuals infected by Trypanosoma cruzi in Mexico and Andean and Central American countries highlights the need for broadened strategies in the struggle against the disease and its vectors. A number of triatomine insects are parasite vectors, each with a different life history. Therefore, it is important that new vector control strategies be proposed, keeping in mind that some species are found in peridomiciliary areas and wild ecotopes. The only viable control strategy is to reduce human interactions with vector insects so that the re-infestation and re-colonisation of human habitats will not take place.

The costs of preventing and treating chagas disease in Colombia.

BACKGROUND: The objective of this study is to report the costs of Chagas disease in Colombia, in terms of vector disease control programmes and the costs of providing care to chronic Chagas disease patients with cardiomyopathy. METHODS: Data were collected from Colombia in 2004. A retrospective review of costs for vector control programmes carried out in rural areas included 3,084 houses surveyed for infestation with triatomine bugs and 3,305 houses sprayed with insecticide. A total of 63 patient records from 3 different hospitals were selected for a retrospective review of resource use. Consensus methodology with local experts was used to estimate care seeking behaviour and to complement observed data on utilisation. FINDINGS: The mean cost per house per entomological survey was $4.4 (in US$ of 2004), whereas the mean cost of spraying a house with insecticide was $27. The main cost driver of spraying was the price of the insecticide, which varied greatly. Treatment of a chronic Chagas disease patient costs between $46.4 and $7,981 per year in Colombia, depending on severity and the level of care used. Combining cost and utilisation estimates the expected cost of treatment per patient-year is $1,028, whereas lifetime costs averaged $11,619 per patient. Chronic Chagas disease patients have limited access to healthcare, with an estimated 22% of patients never seeking care. CONCLUSION: Chagas disease is a preventable condition that affects mostly poor populations living in rural areas. The mean costs of surveying houses for infestation and spraying infested houses were low in comparison to other studies and in line with treatment costs. Care seeking behaviour and the type of insurance affiliation seem to play a role in the facilities and type of care that patients use, thus raising concerns about equitable access to care. Preventing Chagas disease in Colombia would be cost-effective and could contribute to prevent inequalities in health and healthcare.

[Updated geographical distribution and ecoepidemiology of the triatomine fauna (Reduviidae: Triatominae) in Colombia]. / Actualización de la distribución geográfica y ecoepidemiología de la fauna de triatominos (Reduviidae: Triatominae) en Colombia.

Information concerning triatomine records from provinces and municipalities was accumulated-including data indicating natural infections with trypanosomatides-that has been previously published or reported by Colombian provincial health services and research institutes. Altitude appeared to be the main factor responsible for the distribution of the insects. Illustrations summarize the information provided by the above records. A triatomine fauna classification is presented that corresponds to the eco-epidemiological conditions of the country, considering altitude as the factor determining the geographical distribution of these vectors. Rhodnius prolixus, Triatoma dimidiata, Triatoma maculata and Triatoma venosa are considered the major transmission risk species in Colombia, according to the frequency in which they are reported inside dwellings and peridomiciliary areas. Entomological surveillance providess a necessary tool to reinforce the control strategies for Chagas disease. This also allows the evaluation of transmission risk that the sylvatic triatomines represent in Colombia.

Actualización de la distribución geográfica y ecoepidemiología de la fauna de triatominos (Reduviidae: Triatominae) en Colombia / Updated geographical distribution and ecoepidemiology of the triatomine fauna (Reduviidae: Triatominae) in Colombia

La presente publicación recopila la información de registros de triatominos y datos sobre infección natural con tripanosomátidos a nivel departamental y municipal, publicada hasta la fecha así como la reportada por los servicios departamentales de salud e institutos de investigación. Se presentan figuras elaboradas de acuerdo a la información suministrada por los registros y una clasificación de la fauna triatomínica de acuerdo a las condiciones ecoepidemiológicas del país, teniendo en cuenta la altitud como factor determinante en la distribución de estos insectos. Teniendo en cuenta la frecuencia con que se reportan en el domicilio y peridomicilio, se consideran las siguientes especies como las de mayor riesgo de transmisión en Colombia: Rhodnius prolixus, Triatoma dimidiata, Triatoma maculata y Triatoma venosa. Se resalta la importancia de la vigilancia entomológica como herramienta indispensable para reforzar las estrategias de control de la transmisión de la enfermedad de Chagas, permitiendo también la evaluación del riesgo que representan las especies de triatominos silvestres en Colombia.

Information concerning triatomine records from provinces and municipalities was accumulated— including data indicating natural infections with trypanosomatides—that has been previously published or reported by Colombian provincial health services and research institutes. Altitude appeared to be the main factor responsible for the distribution of the insects. Illustrations summarize the information provided by the above records. A triatomine fauna classification is presented that corresponds to the eco-epidemiological conditions of the country, considering altitude as the factor determining the geographical distribution of these vectors. Rhodnius prolixus, Triatoma dimidiata, Triatoma maculata and Triatoma venosa are considered the major transmission risk species in Colombia, according to the frequency in which they are reported inside dwellings and peridomiciliary areas. Entomological surveillance providess a necessary tool to reinforce the control strategies for Chagas disease. This also allows the evaluation of transmission risk that the sylvatic triatomines represent in Colombia.

Genetic structure of Triatoma venosa (Hemiptera: Reduviidae): molecular and morphometric evidence.

Triatoma venosa presents a restricted geographical distribution in America and is considered as a secondary vector of Chagas disease in Colombia and Ecuador. A total of 120 adult insects were collected in domestic and peridomestic habitats in an endemic area of the department of Boyacá, Colombia, in order to determine their genetic structure through morphometric and molecular techniques. The head and wings of each specimen were used for the analyses of size, shape, and sexual dimorphism. A significant sexual dimorphism was found, although no differences in size among the studied groups were detected. Differences were found in the analyzed structures except for male heads. DNA was extracted from the legs in order to carry out the internal transcriber space-2 (ITS-2) amplification and the randon amplified polymorphic DNA (RAPD) analyses. Length polymorphisms were not detected in the ITS-2. Fst and Nm values were estimated (0.047 and 3.4, respectively). The high genetic flow found among the insects captured in the domicile and peridomiciliary environment does not permit a genetic differentiation, thus establishing the peridomicile as an important place for epidemiological surveillance.

Genetic structure of Triatoma venosa (Hemiptera: Reduviidae): molecular and morphometric evidence

Triatoma venosa presents a restricted geographical distribution in America and is considered as a secondary vector of Chagas disease in Colombia and Ecuador. A total of 120 adult insects were collected in domestic and peridomestic habitats in an endemic area of the department of Boyacá, Colombia, in order to determine their genetic structure through morphometric and molecular techniques. The head and wings of each specimen were used for the analyses of size, shape, and sexual dimorphism. A significant sexual dimorphism was found, although no differences in size among the studied groups were detected. Differences were found in the analyzed structures except for male heads. DNA was extracted from the legs in order to carry out the internal transcriber space-2 (ITS-2) amplification and the randon amplified polymorphic DNA (RAPD) analyses. Length polymorphisms were not detected in the ITS-2. Fst and Nm values were estimated (0.047 and 3.4, respectively). The high genetic flow found among the insects captured in the domicile and peridomiciliary environment does not permit a genetic differentiation, thus establishing the peridomicile as an important place for epidemiological surveillance.

[First report of Triatoma nigromaculata (Stål, 1859) (Hemiptera, Reduviidae, Triatominae) for Colombia]. / Primer registro de Triatoma nigromaculata (Stål, 1859) (Hemiptera, Reduviidae, Triatominae) para Colombia.

The presence of Triatoma nigromaculata was recorded for the first time in Colombia in the rural village La Playa in the province of Cauca. A single female was captured from an outdoor area near a household. The presence of Trypanosoma parasites in the specimen was not established due to the poor condition of the specimen. The epidemiological importance of this finding is discussed with respect to the potential for transmission of Chagas disease in the province of Cauca and, more broadly, in Colombia.

Primer registro de Triatoma nigromaculata (Stãl, 1859) (Hemiptera, Reduviidae, Triatominae) para Colombia / First report of Triatoma nigromaculata (Stãl, 1859) (Hemiptera, Reduviidae, Triatominae)

Se registra por primera vez para Colombia la presencia de Triatoma nigromaculata en la vereda La Playa, municipio de El Tambo, departamento del Cauca. Una sola hembra fuecapturada en el peridomicilio. No se pudo realizar el examen para determinar la presencia de rypanosoma debido al mal estado de preservación del ejemplar. Se discute la importancia pidemiológica de esta captura para la transmisión de la enfermedad de Chagas en el departamento del Cauca y en Colombia

Genetic structure of sylvatic, peridomestic and domestic populations of Triatoma dimidiata (Hemiptera: Reduviidae) from an endemic zone of Boyaca, Colombia.

Randomly amplified polymorphic DNA (RAPD) technique was used to study the genetic structure of sylvatic, peridomestic and domestic populations of Triatoma dimidiata. The genetic flow among them was calculated to establish the epidemiological risk of non-domiciliated populations in the transmission of Chagas disease in an endemic area of Boyaca, Colombia. A total of 83 adult specimens were studied: 26 sylvatic, 27 peridomestic and 30 domestic insects. Wright's Fst was 0.071 and the effective migration rate (Nm) 3.3, suggestive of low genetic differentiation and a movement of at least three insects per generation. The calculated percentage of polymorphic loci was 99%, confirming a large average heterozygosity due to a permanent contact between insects of the three populations. These results imply that non-domiciliated populations of T. dimidiata represent an epidemiological risk in the transmission of Chagas disease owing to the fact that they can colonize human dwellings. Close surveillance of non-strictly domiciliated species of triatomines such as T. dimidiata should entail not only the domicile but also the peridomicile and should include control programs of animal reservoirs. Houses enhancement, educational programs, surveillance of reinfestation and of individuals at risk of infection should be priorities in the control policies in endemic regions such as Boavita, Boyaca.

Metric variation among geographic populations of the Chagas vector Triatoma dimidiata (Hemiptera: Reduviidae: Triatominae) and related species.

Eight Triatoma dimidiata populations from different geographic regions were compared along with related species using traditional morphometry of head characters. A method for removing allometric change was used for the intraspecific comparisons, and scaling for the isometric change of size was used for the interspecific comparisons. The intraspecific comparison showed significant head shape differences between T. dimidiata populations correlating with geography, showing a separation between the northern, intermediate, and southern collections (more evident in females), and supporting the idea that this species includes several evolutionarily divergent populations. The positioning of one sylvatic group from Guatemala did not correlate with geography, because it was more closely related to a distinct population of Colombia. This sylvatic group was found in caves, while the Colombian specimens, although collected in houses, may have migrated from nearby caves. Evolutionary and/or ecological influences could be responsible for the head shape similarities between these two groups: a common ancestral origin of both populations or a morphological convergence caused by similar environmental pressures. The interspecific comparisons included four other regional species of the same genus, three of them belonging to the phyllosoma complex (T. pallidipennis, T. mexicana, and T. ryckmani, the latter provisionally) and the fourth one classified in the protracta complex (T. nitida). Both complexes were readily separated by their head dimensions, even after size adjustment, and our data support inclusion of T. dimidiata within the phyllosoma complex.

Morbilidad de la enfermedad de Chagas en fase cronica en Colombia. Deteccion de pacientes chagasicos con cardiopatia en un area endemica del departamento de Boyaca / Morbidity of Chagas's disease in chronic phase on Colombia

Introducción: en Colombia se estima que existen 1.200.000 personas infectadas con T. cruzi. Los estudios publicados sobre cardiomiopatía chagásica en Colombia han sido usualmente descritos en hospitales de tercer nivel. Objetivo: caracterizar desde el punto de vista clínico y electrocardiográfico la cardiomiopatía chagásica crónica en centros de atención primaria en un área endémica. Diseño del estudio: estudio descriptivo, seccional de morbilidad en población chagásica y no chagásica no seleccionadas. Lugar del estudio: municipios de San Eduardo, Zetaquira y Campohermoso, Boyacá. Pacientes: 405 individuos. Mediciones: se consideraron: edad, sexo, escolaridad, antecedentes, síntomas y signos físicos y hallazgos electrocardiográfícos. Se practicaron serologías por test de ELISA e IFI. Se estableció como seropositivo aquel paciente con positividad en las dos pruebas y seronegativo aquél con resultado negativo en las dos técnicas. Análisis estadístico: se calcularon promedios y proporciones de las distintas variables para los dos grupos de acuerdo con el nivel de medición y se establecieron las diferencias de proporciones entre ellos, tomando un nivel de significación del 0.5 por ciento. Resultados: 405 individuos, 205 seropositivos y 200 seronegativos (control). Edad promedio 45 años, 58 por ciento del sexo femenino para ambos grupos. El 80 por ciento del total de los dos grupos no alcanzó un nivel de escolaridad mayor al de primaria completa. Los hallazgos significativos a favor del grupo de seropositivos fueron: contacto con triatominios (p.-O.OOOl), Chagas en hermanos (p :0.01), muerte súbita en hermanos (p:0.04), sensación de palpitaciones (p:0.05), presíncope (p:0.005), angina (p:0.03), insuficiencia mitral (p:0.004), bloqueo de rama derecha (p:0.01), bloqueo bifascicular (p :0.007) y trastornos de la repolarización (p;0.008). Conclusiones: los hallazgos observados en el grupo de pacientes seropositivos con diagnóstico de cardiomiopatía de Chagas, corresponden a estadios clínicos I y II de la enfermedad. La edad media, el predominio en el sexo femenino, el pobre nivel de escolaridad, los antecedentes personales y familiares, son de resaltar por su impacto socio-económico

Estudio clínico epidemiológico de la neoplasia vesical en el Hospital Central de Maracay / Study clinical epidemiologic of the bladder neoplasia in the Hospital Central of Maracay

Conocer la frecuencia, sexo, grupo etario, presentación, antecedentes familiares y personales, métodos diagnósticos y tratamiento de la neoplasia vesical. Estudio holístico comparativo, cuantitativo realizado de forma retrospectiva en un corte longitudinal, desde 1985 a 1999. Se revisaron 32 historias con diagnóstico de neoplasia vesical. Analizamos según variables. Archivos de historias médicas Hospital Central de Maracay. La mayor frecuencia correspondió a la década de 60 años 28,13 por ciento, a predominio del sexo masculino 71,9 por ciento. Signo clínico más frecuente fue hematuria 100 por ciento, el 12,54 por ciento referían antecedentes familiares de cáncer. Tabaquismo en 46,9 por ciento, consumo de café 15,6 por ciento. El 93,75 por ciento no se registró citologías urinarias en la historia. La tríada Jewett se realizó en 12,5 por ciento siendo todos positivos. El 53 por ciento de los pacientes consultaron cuando presentaban estadios avanzados siendo más frecuente el tipo histológico de células transicionales 52,94 por ciento. En estadios tempranos (A, B1), el tratamiento fue resección transuretral combinada o no con radioterapia, en estadios avanzados (B2-D2) el tratamiento variaba desde resecciones transuretrales hasta cistectomías radicales combinadas o no radioterapia o quimioterapia sistémica. La mayoría de los pacientes acuden tardíamente para buscar solución a su enfermedad, debido a que cuando dichos tumores dan síntomas, la enfermedad está avanzada, por lo cual sugerimos hacer pesquisa, diagnóstico precoz y ultrasonido abdominal como extensión del examen físico