Sand fly fauna in Chapare, Bolivia: an endemic focus of Leishmania (Viannia) braziliensis.

Data on the distribution and abundance of Lutzomyia spp. (Diptera: Psychodidae) in Bolivia is scarce. Sand flies from an area of Leishmania (Viannia) braziliensis endemicity in the Isiboro-Secure National Park in the Department of Cochabamba were captured and identified to species. In total, 945 sand flies (789 females and 156 males) belonging to 15 species were collected from the four collection points in two study villages in 2007. With 549 (58.1%) specimens, Lutzomyia shawi was the most abundant species, followed by Lutzomyia (Trichophoromyia) sp. (22.2%), Lutzomyia llanosmartinsi (8.3%), Lutzomyia antunesi (4.3%), and Lutzomyia olmeca (2.1%). Abundance and species composition varied between rainy and dry seasons, with 99.3% of all sand flies being collected outdoors. Because of species abundance and confirmed Leishmania infection in previous entomological collections, we believe Lu. shawi is the vector of L. (Viannia) braziliensis in Isiboro-Secure National Park.

Prevalence of Leishmania spp. infection in domestic dogs in Chapare, Bolivia.

Data on Leishmania spp. infection in dogs in Bolivia is scarce. Dogs from an area where 90% of human cutaneous leishmaniasis (CL) cases are due to Leishmania (Viannia) braziliensis were screened for Leishmania infection using established enzyme-linked immunosorbent antibody test (ELISA) protocols. Although none of the 51 dogs surveyed had clinical lesions indicative of CL, 6 out of 51 (11.8%) sampled dogs tested positive by ELISA.

Biología reproductiva de dos poblaciones de Triatoma infestans (Hemiptera: Reduviidae) en condiciones de laboratorio / Reproductive biology of two populations of Triatoma infestans (Hemiptera: Reduviidae) under laboratory conditions

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.

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.

Co-Infection of Leishmania (Viannia) braziliensis and HIV: report of a case of mucosal leishmaniasis in Cochabamba, Bolivia.

We describe the first case of Leishmania/HIV co-infection reported in Bolivia. Initially hospitalized with a diagnosis of pneumonia and bronchitis, the patient had numerous cutaneous and mucosal lesions caused by Leishmania (Viannia) braziliensis. The patient was also diagnosed as severely immunocompromised because of HIV infection.

Epidemiological monitoring of American tegumentary leishmaniasis: molecular characterization of a peridomestic transmission cycle in the Amazonian lowlands of Bolivia.

Human-made and environmental changes constitute a major risk factor for the (re-)emergence and spread of leishmaniasis; surveillance of the transmission cycle is essential in this context. This study integrated entomological and molecular parasitological techniques to document the transmission pattern of a peridomestic focus of Leishmania in the Isiboro Secure area of Bolivia. First the spatial distribution and relative density of phlebotomine sand flies, genus Lutzomyia, were established. Lutzomyia shawi was the predominant species in domestic and peridomestic environments (90% from all collections). Second, direct application of the hsp70 PCR to sand fly extracts detected Leishmania infections in Lu. shawi only, and gave an estimated infection rate of 0.21 to 0.38%. The cleavage of the hsp70 amplicon with restriction enzymes (hsp70 PCR-RFLP) allowed identification of Le. (V.) braziliensis and Le. (V.) guyanensis in Lu. shawi captured in the same village. These two parasite species were also found in humans from the study region, supporting the co-existence of two transmission cycles involving the same sand fly species. This study demonstrated the use of PCR-RFLP in the identification of Leishmania in sand fly pools which could lead to the development of methods for screening large sand fly populations in Latin America.

American tegumentary leishmaniasis: direct species identification of Leishmania in non-invasive clinical samples.

Species identification is highly relevant for improved prognosis and adequate treatment of American tegumentary leishmaniasis (ATL). PCR-based methods are available for this purpose but should be simplified to improve accessibility. As a first step in this process, this paper describes a simplified protocol for collection of clinical samples. Using samples from 44 Bolivian patients with confirmed ATL, we demonstrated that hsp70 PCR-RFLP on skin scrapings collected with a tooth pick allowed identification of the parasite species with a sensitivity of 95% and specificity of 100%. Our method should greatly facilitate individual patient management and epidemiological surveillance of ATL.