RESUMO
Introduction. El Alférez, a village in Los Montes de María (Bolívar, Colombia) and a macro-focus of leishmaniasis, recorded its first case in 2018, evidencing changes in the distribution and eco-epidemiology of the disease, although interactions between vectors and local fauna remain unknown. Objective. To evaluate the diversity of sandflies and their blood meal sources in the community of El Alférez in the municipality of El Carmen de Bolívar (Bolívar, Colombia). Materials and methods. In 2018, sandflies were collected using LED-based light traps in domestic, peridomestic, and sylvatic ecotopes and identified at the species level. Multiplex polymerase chain reaction targeting the mitochondrial cytochrome B gene was used to analyze blood from the digestive tract. Results. Lutzomyia evansi was the most abundant species (71.85%; n = 485/675), followed by Lu. panamensis, Lu. gomezi, Lu. trinidadensis, Lu. dubitans, Lu. abonnenci, and Lu.aclydifera. Twenty-five percent of the species had blood meals from Canis familiaris (36.00%; n = 9/25), Ovis aries (36.00%; n=9:/25), Bos taurus (24.00%; n = 6/25), Sus scrofa (20.00%; n = 5/25), and Homo sapiens (8.00%; n = 2/25). Lutzomyia evansi registered the highest feeding frequency (68.00%; n = 17/25), predominantly on a single (44.00%; n = 11/25) or multiple species (24.00%; n = 6/25). Conclusion. Results indicate a eclectic feeding behavior in Lu. evansi, implying potential reservoir hosts for Leishmania spp. and increasing transmission risk. This study is a first step towards understanding the diversity of mammalian blood sources used by sandflies, that may be crucial for vector identification and formulation of effective control measures.
Introducción. En 2018, en la vereda El Alférez de Los Montes de María (Bolívar, Colombia), un macrofoco de leishmaniasis, se reportó el primer caso y se evidenciaron cambios en la distribución y ecoepidemiología de la enfermedad. No obstante, las interacciones entre vectores y fauna local aún son desconocidas. Objetivo. Evaluar la diversidad de flebotomíneos y sus fuentes de alimentación sanguínea en la comunidad de El Alférez del municipio de El Carmen de Bolívar (Bolívar, Colombia). Materiales y métodos. En el 2018, se recolectaron flebotomíneos mediante trampas de luz led ubicadas en el domicilio, el peridomicilio y en el área silvestre, y se identificaron a nivel de especie. Se utilizó la reacción en cadena de la polimerasa múltiple dirigida al gen mitocondrial citocromo B para analizar la sangre del aparato digestivo. Resultados. Lutzomyia evansi fue la especie más abundante (71,85 %; n = 485/675), seguida por Lu. panamensis, Lu. gomezi, Lu. trinidadensis, Lu. dubitans, Lu. abonnenci y Lu. aclydifera. El 25 % (n = 25/100) de las especies analizadas tuvieron como fuentes de ingesta sanguínea a Canis familiaris (36 %; n = 9/25), Ovis aries (36 %; n = 9/25), Bos taurus (24 %; n = 6/25), Sus scrofa (20 %; n = 5/25) y Homo sapiens (8 %; n = 2/25). Lutzomyia evansi fue la especie con la mayor frecuencia de alimentación (68 %; n = 17/25), predominantemente de una sola especie (44 %; n = 11/25) o de varias (24 %; n = 6/25).
Assuntos
Insetos Vetores , Leishmaniose , Psychodidae , Animais , Colômbia/epidemiologia , Psychodidae/parasitologia , Insetos Vetores/parasitologia , Humanos , Leishmaniose/epidemiologia , Leishmaniose/transmissão , Comportamento Alimentar , Cães , Bovinos , Citocromos b/genética , Feminino , MasculinoRESUMO
In the Caribbean region of Colombia, Lutzomyia evansi is recognized as the vector for Leishmania infantum and Leishmania braziliensis. Identifying breeding sites and surveying abundance of immature phlebotomine sand flies in urban foci of leishmaniasis are useful tool to design new vector control strategies. The objective of this study was to describe the natural breeding sites of Lu. evansi in peridomiciliary vegetation in a peri-urban area of the Colombian Caribbean region. Between 2013 and 2015, 466 microhabitats were sampled, collecting 621 kg of soil samples. The explored microhabitats were bases and tree holes, fallen trees, animal caves, leaf litter, domestic animal shelters, and the inside of dwellings. The immature phlebotomines were recovered by direct search under the stereoscope and incubation of soil samples. In total, 103 microhabitats, associated with 17 arboreal species, were identified as natural breeding sites. Of 422 immature sandflies detected, 98.6% were found in soils at the base of the trees. Eight species of the genus Lutzomyia were identified, of which Lu. evansi (52.6%) was the most abundant, followed by Lu. rangeliana, Lu. cayennensis cayennensis, Lu. atroclavata, Lu. micropyga, Lu. trinidadensis, Lu. dubitans and Lu. gomezi. The arboreal species Cordia alba was the most used by phlebotomines for the development of their immature stages. From 63 natural breeding sites identified 268 immatures were recovered including 176 Lu. evansi. The accumulated precipitation showed correlation (R2 = 0.643, p = 0.013) with the abundance of developmental stages, which increased in September and October. The natural breeding sites of Lu. evansi exhibited a local pattern of occurrence dependent on rainfall. The physicochemical analysis of the soil samples showed that the natural sites for C. alba were categorized as fertile loam soils. This is the first systematic study that estimates the temporal variation of immature sand flies in peridomiciliary vegetation in a peri-urban focus of leishmaniasis in Colombia.
RESUMO
Visceral leishmaniasis (VL) is caused by the trypanosomatid parasite Leishmania infantum (=Leishmania chagasi), and is epidemiologically relevant due to its wide geographic distribution, the number of annual cases reported and the increase in its co-infection with HIV. Two vector species have been incriminated in the Americas: Lutzomyia longipalpis and Lutzomyia evansi. In Colombia, L. longipalpis is distributed along the Magdalena River Valley while L. evansi is only found in the northern part of the Country. Regarding the epidemiology of the disease, in Colombia the incidence of VL has decreased over the last few years without any intervention being implemented. Additionally, changes in transmission cycles have been reported with urban transmission occurring in the Caribbean Coast. In Europe and North America climate change seems to be driving a latitudinal shift of leishmaniasis transmission. Here, we explored the spatial distribution of the two known vector species of L. infantum in Colombia and projected its future distribution into climate change scenarios to establish the expansion potential of the disease. An updated database including L. longipalpis and L. evansi collection records from Colombia was compiled. Ecological niche models were performed for each species using the Maxent software and 13 Worldclim bioclimatic coverages. Projections were made for the pessimistic CSIRO A2 scenario, which predicts the higher increase in temperature due to non-emission reduction, and the optimistic Hadley B2 Scenario predicting the minimum increase in temperature. The database contained 23 records for L. evansi and 39 records for L. longipalpis, distributed along the Magdalena River Valley and the Caribbean Coast, where the potential distribution areas of both species were also predicted by Maxent. Climate change projections showed a general overall reduction in the spatial distribution of the two vector species, promoting a shift in altitudinal distribution for L. longipalpis and confining L. evansi to certain regions in the Caribbean Coast. Altitudinal shifts have been reported for cutaneous leishmaniasis vectors in Colombia and Peru. Here, we predict the same outcome for VL vectors in Colombia. Changes in spatial distribution patterns could be affecting local abundances due to climatic pressures on vector populations thus reducing the incidence of human cases.
Assuntos
Mudança Climática , Insetos Vetores/crescimento & desenvolvimento , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Psychodidae/crescimento & desenvolvimento , Topografia Médica , Animais , Colômbia/epidemiologia , Simulação por Computador , Geografia , Humanos , Insetos Vetores/parasitologia , Psychodidae/parasitologiaRESUMO
Objetivo: Estimar el tiempo promedio de desarrollo de Lutzomyia evansi. Materiales y métodos: Se inició una colonia de Lutzomyia evansi con individuos recolectados en la zona urbana de la ciudad de Sincelejo (Colombia). La colonia fue mantenida en el laboratorio durante tres generaciones filiales bajo condiciones experimentales promedio de 26°C de temperatura y 94% de humedad relativa. Resultados: La duración del desarrollo de Lutzomyia evansi fue de 36 a 45 días. El tiempo requerido para el desarrollo de los huevos fue en promedio de 6,75 días (rango de 6 a 8 días). La duración en promedio de los diferentes estadios larvales fue 5,75 días en larvas de primer estadio (rango de 5 a 8 días), 5,75 días en larvas de segundo estadio (rango de 4 a 7 días), 5 días en larvas de tercer estadio (rango de 4 a 7 días) y 7 días en larvas de cuarto estadio (rango e 6 a 8 días). En la fase de pupa, la duración en promedio fue de 9,75 días (rango de 7 a 17 días). Conclusiones: El tiempo promedio requerido para el desarrollo de Lutzomyia evansi, comprendido desde la alimentación sanguínea de la hembra madre hasta la emergencia del adulto, es de 40 días.
Objective: To estimate the mean development time for Lutzomyia evansi. Materials and methods: A laboratory colony of Lutzomyia evansi was started from sand flies collected in the urban area of the City of Sincelejo, Colombia. The colony was main-tained during three filial generations under experimental conditions of 26°C of mean tem-perature, and 94% of average relative humidity. Results: The duration of the development of Lutzomyia evansi was from 36 to 45 days. The development time for eggs was, on average, 6, 75 days (interval from 6 to 8 days). The mean duration of the different larval instars was 5,75 days in first instar (interval from 5 to 8 days), 5,75 days in second instar (interval from 4 to 7 days), 5 days in third instar (in-terval from 4 to 7 days) and 7 days in fourth instar (interval from 6 to 8 days). In the stage of pupa the development time was, on average, 9, 75 days (interval from 7 to 17 days). Conclusions: The mean development time for Lutzomyia evansi, from the female's blood meal to adult emergence, is 40 days.