Geographical distribution update of Triatoma dispar (Hemiptera: Reduviidae: Triatominae) in Ecuador.

Were recorded for the first time Triatoma dispar species at an altitude of 1,200 masl in Milpe km 90, Canton San Miguel de los Bancos, Province of Pichincha and its geographical distribution is updated in Ecuador. Triatomines were collected during a sandflies study (Leishmania vectors) in peridomestic areas and forest remnants. Milpe km 90 did not present clinical evidence or transmission of the Chagas disease or enzootic circulation of Trypanosoma cruzi; however is in an area of high epidemiological risk. The present work contributes to the inventory of the Ecuador triatomine fauna and updating geographical distribution of T. dispar, a wild species with vectorial potential, which has already colonized domestic and peridomestic environments in Esmeraldas and Loja

Actualización de la distribución geográfica de Triatoma dispar (Hemiptera: Reduviidae: Triatominae) en Ecuador

Were recorded for the first time Triatoma dispar species at an altitude of 1,200 masl in Milpe km 90, CantonSan Miguel de los Bancos, Province of Pichincha and its geographical distribution is updated in Ecuador. Triatomines were collected during a sandflies study (Leishmania vectors) in peridomestic areas and forest remnants. Milpe km 90 did not present clinical evidence or transmission of the Chagas disease or enzootic circulation of Trypanosoma cruzi; however is in an area of high epidemiological risk. The present work contributes to the inventory of the Ecuador triatomine fauna and updating geographical distribution of T. dispar, a wild species with vectorial potential, which has already colonized domestic and peridomestic environments in Esmeraldas and Loja.Se registra por primera vez la especie Triatoma dispar a una altitud de 1.200 msnm en la localidad de Milpe km 90, Cantón San Miguel de los Bancos, Provincia de Pichincha y se actualiza su distribución geográfica en el Ecuador. Los triatominos se colectaron durante un estudio de flebótomos (vectores de Leishmania), en peridomicilio y remanentes de bosque. Milpe km 90 no presentó evidencia clínica, ni transmisión de la enfermedad de Chagas o circulación enzoótica de Trypanosoma cruzi; sin embargo, se encuentra en una zona de riesgo epidemiológico alto. El presente trabajo contribuye al inventario de la fauna de triatominos del Ecuador y a la actualización de la distribución geográfica de T. dispar, una especie silvestre con potencial rol vectorial, que ya ha colonizado ambientes domésticos y peridomésticos en Esmeraldas y Loja

New insight in lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in Ecuador

Fasciolosis is a widely distributed disease in livestock in South America but knowledge about the epidemiology and the intermediate hosts are scarce in Ecuador. During 3 months, lymnaeid snails were sampled (n=1482) in Pichincha province in two sites located in a highly endemic area. The snails were identified (based on morphology and ITS2 sequences) and the infection status was established through microscopic dissection and a multiplex PCR-based technique. If morphologic-based techniques were not useful to accurately named the one species collected, alignment study ascribed it to L. schirazensis. Rediae were observed in 1.75 % (26/1482) and Fasciola sp. DNA was detected in 6% (89/1482) of the collected snails. The COX1 region permitted the parasite species identification: F. hepatica. The relative sensitivity and specificity of the microscope related to the PCR results was 25.84% and 99.78% respectively. The mean size of the snails recorded positive for F. hepatica through crushing and microscopy was significantly higher than the mean size of negative snails. There was not such difference in PCR positive snails. The role of G. schirazensis as an intermediate host of F. hepatica in Ecuador is discussed and a hypothesis of an adaptation of the snail to the trematoda is formulated. For the first time, an epidemiological survey, based on molecular biology-based techniques assessed the role of lymnaeid snail in the epidemiology of fasciolosis in Ecuador

Is Galba schirazensis (Mollusca, Gastropoda) an intermediate host of Fasciola hepatica (Trematoda, Digenea) in Ecuador?

Fasciolosis is a widely distributed disease in livestock in South America but knowledge about the epidemiology and the intermediate hosts is relatively scarce in Ecuador. For three months, lymnaeid snails were sampled (n = 1482) in Pichincha Province at two sites located in a highly endemic area. Snails were identified (based on morphology and ITS-2 sequences) and the infection status was established through microscopic dissection and a multiplex polymerase chain reaction (PCR)-based technique. Techniques based on morphology were not useful to accurately name the collected snail species. Comparison with available DNA sequences showed that a single snail species was collected, Galba schirazensis. Live rediae were observed in 1.75% (26/1482) and Fasciola sp. DNA was detected in 6% (89/1482) of collected snails. The COX-1 region permitted identification of the parasite as Fasciola hepatica. The relative sensitivity and specificity of the microscope study, compared to PCR results, were 25.84% and 99.78%, respectively. The mean size of the snails recorded positive for F. hepatica through crushing and microscopy was significantly higher than the mean size of negative snails, but there was no such difference in PCR-positive snails. The role of G. schirazensis as an intermediate host of F. hepatica in Ecuador is discussed and the hypothesis of an adaptation of the parasite to this invasive snail is proposed. For the first time, an epidemiological survey based on molecular biology-based techniques assessed the possible role of lymnaeid snails in the epidemiology of fasciolosis in Ecuador

Prevalence of Fasciola hepatica infection in Galba cousini and Galba schirazensis from an Andean region of Ecuador

Some Lymnaeid snails are intermediate hosts of the liver fluke Fasciola hepatica, the causal agent of fasciolosis, a zoonotic parasitic disease. Human and livestock fasciolosis has been reported in a highland community located in the Chimborazo Province of the Ecuadorian Andes. However, no previous study has been carried out to identify which snail species act as intermediate host/s of F. hepatica. This study first aimed to identify the intermediate snail species and secondly to determine the prevalence of natural infection with F. hepatica in 230 lymnaeid snails sampled from irrigation and drainage canals in this area. The first objective entailed observations of shell morphology and internal organs as well as sequencing of the cytochrome oxidase subunit 1 (COI) gene. For the second objective, we used classic parasitological methods (observation of rediae and cercarial emission) and PCR amplification specie-specific to F. hepatica. COI haplotype networks were built to elucidate phylogeographic relationships between the snail populations from this highland community with other American and worldwide populations. We identified two lymnaeid Galba cousini and Galba schirazensis and found high infection rates of F. hepatica in G. cousini, but these differed according to the method used, with PCR showing a higher rate (61 ± 20%) compared to rediae observation (29 ± 17%). F. hepatica in G. schirazensis was identified only by DNA amplification. G. cousini populations were genetically structured by geographic distance whereas G. schirazensis populations showed very low genetic diversity. The higher abundance and infection rate of G. cousini compared to G. schirazensis suggests that the former is likely the specie responsible for F. hepatica transmission in this region.Fil: Celi Erazo, Maritza. Universidad Central del Ecuador; EcuadorFil: Alda, Maria del Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Université Montpellier II; Francia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Montenegro Franco, María. Universidad Central del Ecuador; EcuadorFil: Pavon, Diego. Universidad Central del Ecuador; EcuadorFil: Minda Aluisa, Elizabeth. Universidad Central del Ecuador; EcuadorFil: Calvopiña, Manuel. Universidad de Las Américas.; EcuadorFil: Pointier, Jean Pierre. Université de Perpignan; Francia. Centre National de la Recherche Scientifique; FranciaFil: Hurtrez Boussès, Sylvie. Université Montpellier II; Francia. Centre National de la Recherche Scientifique; FranciaFil: Cevallos, William. Universidad Central del Ecuador; EcuadorFil: Benítez Ortíz, Washington. Universidad Central del Ecuador; EcuadorFil: Rodríguez Hidalgo, Richar. Universidad Central del Ecuador; Ecuado

Bayesian evaluation of three serological tests for detecting antibodies against brucella spp. Among humans in the Northwestern Part of Ecuador

Brucellosis is an important but neglected zoonosis that causes serious economic losses both in livestock and human populations. The aim of the present study was to estimate the true prevalence of brucellosis together with diagnostic sensitivity and specificity of three serological tests in humans of the northwestern part of Ecuador using a Bayesian approach adjusted for the dependencies among the multiple tests to avoid any misinterpretation. In addition, the causal agent responsible for human brucellosiswas also identified. Using a total of 3,733 samples collected from humans in this area between 2006 and 2008, the prevalence of human brucellosis and the diagnostic test characteristics of the Rose Bengal fast agglutination test (RBT), Wright's slow agglutination test with ethylenediaminetetraacetic acid disodium salt dehydrate (EDTA) (SAT-EDTA), and indirect ELISA (iELISA) were estimated using a Bayesian approach. The estimated true prevalence of human brucellosis was 1%(credibility interval: 0.4-1.6). The sensitivities of iELISA and RBT were higher than and similar (95.1% and 95.0%, respectively) to those of SAT-EDTA (60.8%). Even though all tests indicated a high specificity (>99.0%), the specificity of SAT-EDTAwas highest (99.9%). The circulating strain in this study area was identified to be Brucella abortus biotype 4 based on culture and microbiological characterization. The RBT and the iELISA are recommended for estimating the true prevalence of human brucellosis and/or for surveillance programs following their high sensitivities and specificities. The proposed strategy supports evidence-based medicine for clinicians and policy-makers to ensure appropriate preventive and control program of brucellosis worldwide

First Report of Orchitis in Man Caused by Brucella abortus Biovar 1 in Ecuador.

Abstract. We present a 44-year-old man from a rural community in northern Ecuador who worked on a cattle farm where he was involved with primary veterinary care, including assistance during births (or calving) and placenta retention and artificial insemination, with minimal precautions. In September of 2009, quite abruptly, he developed asthenia and hypersomnia without any apparent cause or symptoms like fever, chills, or night sweats. On November 14, 2009, he suffered from pain and edema in the right testicle that coincided with pain in the abdomen. Clinical, serological, and bacteriological investigations confirmed the first case of unilateral orchitis in man in Ecuador caused by Brucella abortus biovar 1. Because brucellosis is a neglected disease, special attention should be given to it in the training of medical and veterinary students

Human Brucellosis in Northwest Ecuador: Typifying Brucella spp., Seroprevalence, and Associated Risk Factors

Human brucellosis in Ecuador is underreported and based only on passive surveillance. Since 2008, brucellosis was removed from the list of communicable diseases in the country. Until now, the true human brucellosis picture has not yet been determined. The aim of this study was to determine the seroprevalence of the disease, identify risk factors associated with brucellosis seropositivity in humans, and isolate circulating strains of Brucella spp. in the northwestern part of Ecuador. Between 2006 and 2008, a large transect survey was conducted, based on blood sampling of people from the northwestern part of Ecuador (n=3733) together with an epidemiological inquiry. On the basis of three diagnostic tests used in parallel, the overall seroprevalence was estimated as 1.88% (95% confidence interval [CI] 1.48-2.38). Based on a multivariable random effects logistic regression analysis, the main risk factors associated with human brucellosis seropositivity were contact with livestock (odds ratio [OR]=3.0; CI 1.25-7.08), consumption of fetus and placenta (OR=2.5; CI 1.18-5.22), and involvement in activities at risk for brucellosis infection (OR=1.8; CI 1.00-3.35). Noticeable variation in brucellosis seropositivity among humans within cantons was observed. The circulating strain was Brucella abortus biotype 4. This study emphasized that contact with livestock, consumption of fetus and placenta, and occupational hazard group were all significant risk factors for the transmission of brucellosis among individuals in the northwestern part of Ecuador. Alongside encouraging the launching of educational campaigns against brucellosis, especially in rural areas where 36% of the population lives, controlling this zoonotic disease in animals will directly benefit its prevention in humans, especially because there is no safe and efficacious vaccine against brucellosis in humans