Results and evaluation of the expansion of a model of comprehensive care for Chagas disease within the National Health System: The Bolivian Chagas network

Background: Most people with chronic Chagas disease do not receive specific care and therefore are undiagnosed and do not receive accurate treatment. This manuscript discusses and evaluates a collaborative strategy to improve access to healthcare for patients with Chagas in Bolivia, a country with the highest prevalence of Chagas in the world. Methods: With the aim of reinforcing the Chagas National Programme, the Bolivian Chagas Platform was born in 2009. The first stage of the project was to implement a vertical pilot program in order to introduce and consolidate a consensual protocol-based healthcare, working in seven centers (Chagas Platform Centers). From 2015 on the model was extended to 52 primary healthcare centers, through decentralized, horizontal scaling-up. To evaluate the strategy, we have used the WHO ExpandNet program. Results: The strategy has significantly increased the number of patients cared for, with 181,397 people at risk of having T. cruzi infection tested and 57,871 (31·9%) new diagnostics performed. In those with treatment criteria, 79·2% completed the treatment. The program has also trained a significant number of health personnel through the specific Chagas guidelines (67% of healthcare workers in the intervention area). Conclusions: After being recognized by the Chagas National Programme as a healthcare model aligned with national laws and priorities, the Bolivian platform of Chagas as an innovation, includes attributes that they have made it possible to expand the strategy at the national level and could also be adapted in other countries

Intradomiciliary and peridomiciliary captures of sand flies (Diptera: Psychodidae) in the leishmaniasis endemic area of Chapare province, Tropic of Cochabamba, Bolivia

In South America, cutaneous leishmaniasis is the most frequent clinical form of leishmaniasis. Bolivia is one of the countries with higher incidence, with 33 cases per 100,000 individuals, and the disease is endemic in 70% of the territory. In the last decade, the number of cases has increased, the age range has expanded, affecting children under 5 years old, and a similar frequency between men and women is found. An entomological study with CDC light traps was conducted in three localities (Chipiriri, Santa Elena and Pedro Domingo Murillo) of the municipality of Villa Tunari, one of the main towns in the Chapare province (Department of Cochabamba, Bolivia). A total of 16 specimens belonging to 6 species of the genus Lutzomyia were captured: Lu. aragaoi, Lu. andersoni, Lu. antunesi, Lu. shawi, Lu. yuilli yuilli and Lu. auraensis. Our results showed the presence of two incriminated vectors of leishmaniasis in an urbanized area and in the intradomicile. More entomological studies are required in the Chapare province to confirm the role of vector sand flies, the intradomiciliary transmission of the disease and the presence of autochthonous cases of cutaneous leishmaniasis

Caracterización de la infestación de viviendas por Aedes aegypti en el área metropolitana de Cochabamba, Bolivia: nuevos registros altitudinales

La rápida proliferación del vector en áreas de clima cálido y baja altitud, como el oriente y la amazonia boliviana, generó la necesidad de analizar la adaptabilidad del A. aegypti en zonas templadas, tal es el caso de los valles mesotérmicos de la ciudad metropolitana de Cochabamba.Objetivo: la evaluación entomológica se realizó en una muestra de 264 viviendas seleccionadas al azar en Abril del 2016. El área de estudio abarca zonas urbanas de seis municipios (Cercado, Sacaba, Colcapirhua, Tiquipaya, Quillacollo y Vinto) del departamento de Cochabamba. El diseño para el estudio fue epidemiológico, transversal de diagnóstico comunitario.Métodos: de la muestra referida, 100 viviendas se encontraron larvas de A. aegypti , que corresponde a un 38% de infestación larvaria y un Índice Breteau de 1,0. Las llantas, turriles y recipientes desechables son un factor de riesgo para la propagación y adaptación del vector en nuestra región.Resultados: los hallazgos confirman la dispersión del A. aegypti con algunas regiones con mayor prevalencia (zona sud de cercado urbano, Colcapirhua y Quillacollo en el valle bajo). También se evidenció por primera vez que la dispersión y colonización de larvas de A. aegypti en el área de estudio alcanzó una altura mínima de 2 538 m/s/n/m. y una altura máxima de 2 623 m.s.n.m.Conclusiones: La prevención y el control de A. aegypti , en la metrópoli de Cochabamba va a requerir un trabajo mancomunado integral e intersectorial enfocados en una estrategia de intervención de gestión socioambiental de corresponsabilidad y participación comunitaria, generando como resultado un Manejo Integrado del Vector.Palabras claves: Aedes aegypti , epidemiología, infestación, Bolivia

Resistance to starvation of Triatoma rubrofasciata (De Geer, 1773) under laboratory conditions (Hemiptera: Reduviidae: Triatominae)

The present work aims at learning the period of resistance to starvation (molting/death) of Triatoma rubrofasciata in different stages of development and the respective loss of weight until death. Eggs of specimens from the greater area of the city of Sao Luis in the State of Maranhao, Brazil, yielded approximately 300 nymphs. These nymphs were placed in labelled Borrel glasses, in which they were weekly fed on rats (Rattus norvegicus), until reaching the stage to be observed. The experiments were conducted in a climatic chamber regulated at 29+/-1 C, 70% relative humidity and 12 hr photoperiod. The resistance to starvation increased according to the stage of development, except for adult bugs, whose results were similar to the 3rd stage nymphs. In all these development stages there was an abrupt loss of weight in the first week, followed by a gradual loss until death. Comparing this work with those of other authors, it was observed that T. rubrofasciata is among the less resistant triatomine species

Spatial and temporal distribution of house infestation by Triatoma infestans in the Toro Toro municipality, Potosi, Bolivia

Triatoma infestans is the main vector of Trypanosoma cruzi in Bolivia. The species is present both in domestic and peridomestic structures of rural areas, and in wild ecotopes of the Andean valleys and the Great Chaco. The identification of areas persistently showing low and high house infestation by the vector is important for the management of vector control programs. This study aimed at analyzing the temporal and spatial distribution of house infestation by T. infestans in the Toro Toro municipality (Potosi, Bolivia) between 2009 and 2014, and its association with environmental variables. House infestation and T. infestans density were calculated from entomological surveys of houses in the study area, using a fixed-time effort sampling technique. The spatial heterogeneity of house infestation was evaluated using the SatScan statistic. Association between house infestation with Bioclim variables (Worldclim database) and altitude was analyzed using a generalized linear model (GLM) with a logit link. Model selection was based on the Akaike information criteria after eliminating collinearity between variables using the variable inflation factor. The final model was used to create a probability map of house infestation for the Toro Toro municipality. A total of 73 communities and 16,489 house evaluation events were analyzed. Presence of T. infestans was recorded on 480 house evaluation events, giving an overall annual infestation of 2.9% during the studied period (range 1.5-5.4% in 2009 and 2012). Vector density remained at about 1.25 insects/ house. Infestation was highly aggregated in five clusters, including 11 communities. Relative risk of infestation within these clusters was 1.7-3.9 times the value for the regional average. Four environmental variables were identified as good descriptors of house infestation, explaining 57% of house infestation variability. The model allowed the estimation of a house infestation surface for the Toro Toro municipality. Conclusion: This study shows that residual and persistent populations of T. infestans maintain low house infestation, representing a potential risk for the transmission of T. cruzi in these communities, and it is possible to stratify house infestation using EV, and produce a risk map to guide the activities of vector control interventions in the municipality of Toro Toro (Potosi, Bolivia).Fil: Espinoza Echeverria, Jorge. Centro de Pesquisas Rene Rachou; BrasilFil: Rodriguez, Antonio Nogales. Servicio Nacional de Salud. Programa Nacional de Chagas; BoliviaFil: Cortez, Mirko Rojas. Salud y Medioambiente; BoliviaFil: Diotaiuti, Liléia Gonçalves. Centro de Pesquisas Rene Rachou; BoliviaFil: Gorla, David Eladio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Biología reproductiva de dos poblaciones de Triatoma infestans (Hemiptera: Reduviidae) en condiciones de laboratorio

Objectives: in the present study, we documented the reproductive biology of two populations of T. infestans, from the mesothermic Andean Valleys (20 de Octubre) and the Chaco Serrano (Mataral) in laboratory conditions. Methods: there was used 15 pairs of T. infestans populations (Mataral and 20 de Octubre). The control population was colonies of T. infestans from laboratory. The insects were fed on chickens for 45 minutes and kept in a climate chamber at 28 ± 3 ° C, 60 ± 5%. The following parameters and rates were calculated: Fecundity, Fertility, oviposition index (IO), fertility index (FI). Results: it was observed that the T. infestans strain from 20 de Octubre locality, presented the greatest number of eggs per day, with a daily fecundity average rate of (1.95 ± 1.5), a fertility of 95.6% (IO) averaged 0.43 (IF) average of 0.9. Statistical analysis shown that the 20 de octubre locality, presented significant values between variables of number of eggs and the weight of triatomines with a ratio of R2 = 0.77 and a significant Pearson correlation. Conclusions: under laboratory conditions two different populations of T. infestans coming from different regions of Bolivia, shown different patterns of fecundity and fertility, these data are of valuable importance to be considered by vector control programs, since showed that the life cycle of the same vector species may vary according to geographical area, therefore, is very important to continue with studies that describe and help to understand the biology of the main vector species in Bolivia.Objetivos: en el presente estudio, se documentó la biología reproductiva de dos poblaciones de T. infestans provenientes de los Valles Mesotérmicos Andinos (20 de Octubre) y del Chaco Serrano (Mataral), en condiciones de laboratorio. Métodos: se utilizaron 15 parejas de T. infestans por población (Mataral y 20 de Octubre) y como población control colonias de T. infestans de laboratorio; siendo alimentados en gallinas durante 45 minutos y mantenidos en una cámara climática a 28±3°C, 60±5%. Se calcularon los siguientes parámetros e índices: Fecundidad, Fertilidad, Índice de Ovipostura (IO), Índice de Fertilidad (IF). Resultados: se observó que las cepa de T. infestans de la localidad 20 de Octubre, presentaron mayor número de huevos; fecundidad promedio por día de (1.95±1.5), una fertilidad de 95.6%, (IO) promedio fue de 0.43 y (IF) promedio de 0.9. Análisis estadísticos indicaron que la localidad 20 de Octubre presentó valores significativos entre variables de número de huevos y peso de los triatominos con una relación de R2=0,77 y una correlación de Pearson (p=0,0008). Conclusiones: en condiciones de laboratorio poblaciones diferentes de T. infestans de diferentes regiones de Bolivia presentan patrones de Fecundidad y Fertilidad diferentes; estos datos son de suma importancia para ser considerados por los Programas de Control Vectorial ya que el ciclo biológico de una misma especie vectora puede variar en función al área geográfica, por lo cual es muy importante continuar con estudios que describan y ayuden a comprender la biología de las principales especies vectores en Bolivia

Susceptibility of Triatoma infestans to deltamethrin in Rio Grande do Sul, Brazil

Strategies for controlling Chagas disease are based on spraying infested houses with pyrethroid insecticides. However, the intense use of these insecticides has promoted resistance of Triatoma infestans and, in Argentina, Bolivia and Southern Brazil, low levels of resistance have been reported. Due to the persistence of T. infestans in the state of Rio Grande do Sul (RS), we evaluated the occurrence of deltamethrin resistance in four strains from different municipalities in comparison to two susceptible strains from Brazil and one resistant strain from Bolivia. The results indicated the absence of resistance in T. infestans from RS