Evaluacion por western blot, inmunofluorescencia indirecta y elisa de perros infectados con leishmania (leishmania) infantum

Objetivo Evaluar el desempeño de las pruebas empleadas en Colombia para el diagnóstico de la leishmaniasis visceral canina y adaptar una técnica de Western blot empleando animales experimental y naturalmente infectados.  Metodología Se obtuvieron sueros de 10 perros infectados experimentalmente con L. infantum, 5 perros infectados naturalmente, 16 perros sanos, 26 de reacción cruzada (infectados con Babesia canis, Erhlichia canis, Dirofilaria immitis, Trypanosoma cruzi, Leishmania (Viannia) spp.), 40 de zonas no endémicas y 150 de zona endémica.  Todos fueron evaluados mediante las pruebas de inmunofluorescencia indirecta (IFI), ELISA y Western blot (WB).  Resultados Se encontró que IFI tuvo el mayor porcentaje de positividad en los perros infectados (73 %) mientras que el menor porcentaje de falsos positivos se obtuvo por WB (2,5 %).  La prueba de ELISA fue la menos eficiente. Fueron reconocidas 24 fracciones antigénicas, las bandas de 29, 34, 50, 69, 75, 86, 99 y 123 kDa fueron responsables de reacciones inespecíficas en los sueros de perros sanos, de zona no endémica y de reacción cruzada.  Las bandas por debajo de 29 kDa mostraron ser potencialmente diagnósticas, especialmente la fracción de 13 kDa.  Conclusiones Los métodos directos y serológicos pueden subdiagnosticar la infección por Leishmania, solamente un constructo que combine tanto pruebas directas como indirectas sería la forma más eficiente de diagnóstic

Prevalence of canine visceral leishmaniasis in municipalities of huila, colombia

With the purpose of establishing the prevalence of canine leishmaniasis a descriptive study was carried out in 17 villages of the municipalities of Neiva, Tello and Algeciras, in the department of Huila, Colombia. The selected canine population was composed of 307 dogs, which were submitted to clinical examination, stained smears of lymph node needle aspiration, and bleeding for serological analysis by the Immunofluorescent Antibody Tests (IFAT). The canine population was conformed by mestizo dogs, with a 3 year age average; 30,6 % were females. Upon physical examination loss of weight was observed in 31% of dogs; lynfadenopathy of the popliteal node in 3,2 %; alopecia in 21,8 %, eritematous lesions in 11,5 % and skin ulcers in 3,3 %. 17,2 % of the dogs has a positive serology and in 1.43% of them, amastigotes were observed in the smears of lymph node aspirates. These prevalence of anti-L. chagasi antibodies is relatively high compared with other studies in Colombia and in other countries. The present study, confirms the endemic nature of the illness in the area, high lighting the need for strengthening public health surveillance and active search for human cases.Con el propósito de establecer la prevalencia de leishmaniosis canina se efectuó un estudio descriptivo en 307 caninos, ubicados en 17 veredas de los municipios de Neiva, Tello y Algeciras, a los cuales se les practicó examen clínico, punción y aspiración del ganglio linfático poplíteo para extendido y coloración en lámina; toma de sangre completa por venopunción para análisis mediante la técnica de inmunofluorescencia indirecta. La población canina estuvo conformada por perros mestizos con edad promedio de tres años; el 30,6 % fueron hembras y el 69,4 % machos. En el examen físico de los caninos se observó: enflaquecimiento, 31 %; onicogrifosis, 29,3 %; linfadenitis de ganglio poplíteo 3,2 %; áreas alopécicas 21,8 %; lesiones eritematosas 11,5 % y úlceras cutáneas 3,3 %. El 1,4 % de los caninos analizados presentaron amastigotes en el aspirado y el 17,2 % fueron seropositivos. La prevalencia de anticuerpos contra L. chagasi es alta comparada con otros estudios realizados en Colombia y otros países, corroborando la endemicidad de la enfermedad en el área. Por consiguiente, es necesario fortalecer las estrategias de vigilancia epidemiológica y la búsqueda activa de casos humanos

Colonization of Ochlerotatus taeniorhynchus from Riohacha, Colombia

The main objective of the present work was to establish and maintain a colony of Ochlerotatus taeniorhynchus, Riohacha strain, under laboratory conditions and to study its life cycle. The colony\u27s insectary was established from adult male and female mosquitoes collected from peripheral neighborhoods of Riohacha, Colombia. Environmental conditions established in the insectary were 26.5°C average temperature, 80% average relative humidity, and 12 h photoperiodicity. Eight continuous generations were taken into account for maintaining the mosquitoes and analyzing their life cycle. The male mosquito\u27s average life cycle was 26.8 days. The female\u27s cycle was 30.8 days. Analysis of each of the biological stages of development (mean days) produced the following results: egg incubation 4.55 ± 0.291, larvae 8.28 ± 0.499, pupae 1.32 ± 0.215, adult male 12.65 ± 5.920, and adult female 16.73 ± 6.034. The Riohacha colony has been maintained for 32 generations in 31 months. Comparison of the Riohacha colony with the previously established Cartagena and Barranquilla colonies showed few differences in the duration of stages of the life cycle between strains. Copyright © 2005 by the American Mosquito Control Association, Inc

Life tables of Lutzomyia longiflocosa under semi-field conditions

Phlebotomine sandflies are a group of insects of importance in public health, given their capacity to transmit pathogens, such as Leishmania spp. In Colombia, Lutzomyia longiflocosa is considered the most probable vector in leishmaniasis outbreaks in the departments of Norte de Santander, Huila, and Tolima. However, several aspects of its biology and ecology are unknown, which directly affect it is role as a vector of the parasite. So it is necessary to know more about the characteristics inherent to its life cycle and life tables to make epidemic prediction models, and implement prevention of vector control measures against future outbreaks of the disease.Para acceder a la videoconferencia completa, hacer clic en "Enlace externo".Sociedad Latinoamericana de Ecología de Vectore

High Levels of Diversity in <i>Anopheles</i> Subgenus <i>Kerteszia</i> Revealed by Species Delimitation Analyses

The Anopheles subgenus Kerteszia is a poorly understood group of mosquitoes that includes several species of medical importance. Although there are currently twelve recognized species in the subgenus, previous studies have shown that this is likely to be an underestimate of species diversity. Here, we undertake a baseline study of species delimitation using the barcode region of the mtDNA COI gene to explore species diversity among a geographically and taxonomically diverse range of Kerteszia specimens. Beginning with 10 of 12 morphologically identified Kerteszia species spanning eight countries, species delimitation analyses indicated a high degree of cryptic diversity. Overall, our analyses found support for at least 28 species clusters within the subgenus Kerteszia. The most diverse taxon was Anopheles neivai, a known malaria vector, with eight species clusters. Five other species taxa showed strong signatures of species complex structure, among them Anopheles bellator, which is also considered a malaria vector. There was some evidence for species structure within An. homunculus, although the results were equivocal across delimitation analyses. The current study, therefore, suggests that species diversity within the subgenus Kerteszia has been grossly underestimated. Further work will be required to build on this molecular characterization of species diversity and will rely on genomic level approaches and additional morphological data to test these species hypotheses

High Levels of Diversity in Anopheles Subgenus Kerteszia Revealed by Species Delimitation Analyses

The Anopheles subgenus Kerteszia is a poorly understood group of mosquitoes that includes several species of medical importance. Although there are currently twelve recognized species in the subgenus, previous studies have shown that this is likely to be an underestimate of species diversity. Here, we undertake a baseline study of species delimitation using the barcode region of the mtDNA COI gene to explore species diversity among a geographically and taxonomically diverse range of Kerteszia specimens. Beginning with 10 of 12 morphologically identified Kerteszia species spanning eight countries, species delimitation analyses indicated a high degree of cryptic diversity. Overall, our analyses found support for at least 28 species clusters within the subgenus Kerteszia. The most diverse taxon was Anopheles neivai, a known malaria vector, with eight species clusters. Five other species taxa showed strong signatures of species complex structure, among them Anopheles bellator, which is also considered a malaria vector. There was some evidence for species structure within An. homunculus, although the results were equivocal across delimitation analyses. The current study, therefore, suggests that species diversity within the subgenus Kerteszia has been grossly underestimated. Further work will be required to build on this molecular characterization of species diversity and will rely on genomic level approaches and additional morphological data to test these species hypotheses

Life tables and reproductive parameters of Lutzomyia spinicrassa (Diptera: Psychodidae) under laboratory conditions

Lutzomyia spinicrassa is a vector of Leishmania braziliensis in Colombia. This sand fly has a broad geographical distribution in Colombia and Venezuela and it is found mainly in coffee plantations. Baseline biological growth data of L. spinicrassa were obtained under experimental laboratory conditions. The development time from egg to adult ranged from 59 to 121 days, with 12.74 weeks in average. Based on cohorts of 100 females, horizontal life table was constructed. The following predictive parameters were obtained: net rate of reproduction (8.4 females per cohort female), generation time (12.74 weeks), intrinsic rate of population increase (0.17), and finite rate of population increment (1.18). The reproductive value for each class age of the cohort females was calculated. Vertical life tables were elaborated and mortality was described for the generation obtained of the field cohort. In addition, for two successive generations, additive variance and heritability for fecundity were estimated