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Data paper related to medical entomology, submitted to GigaScience

Vector-borne diseases are responsible for more than 17% of human cases of infectious diseases. In most situations, effective control of debilitating and deadly vector-bone diseases (VBDs), such as malaria, dengue, chikungunya, yellow fever, Zika and Chagas requires up-to-date, robust and comprehensive information on the presence, diversity, ecology, bionomics and geographic spread of the organisms that carry and transmit the infectious agents. Huge gaps exist in the information related to these vectors, creating an essential need for campaigns to mobilise and share data. The publication of data papers is an effective tool for overcoming this challenge. These peer-reviewed articles provide scholarly credit for researchers whose vital work of assembling and publishing well-described, properly-formatted datasets often fails to receive appropriate recognition. To address this, GigaScience 's sister journal GigaByte partnered with the Global Biodiversity Information Facility (GBIF) to publish a series of data papers, with support from the Special Programme for Research and Training in Tropical Diseases (TDR), hosted by the World Health Organisation (WHO). Here we outline the initial results of this targeted approach to sharing data and describe its importance for controlling VBDs and improving public health.

This study evaluated the effect of Calcium hydroxide (Ca(OH)

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. Fil: Estrada Mendez, Luis Gregorio. Universidad de Sucre.; Colombia. Ministerio de Salud. Instituto Nacional de Medicina Tropical; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ortega, Edgardo Nicolás. Universidad de Sucre.; Colombia Fil: Vivero, Rafael José. Institucion Universitaria Colegio Mayor de Antioquia.; Colombia Fil: Bejarano, Eduar Elías. Universidad de Sucre.; Colombia Fil: Cadena, Horacio. Institucion Universitaria Colegio Mayor de Antioquia.; Colombia

Objective To evaluate the environmental and ecological factors associated with Leishmania transmission and vector abundance in Chaparral, Tolima-Colombia. Methods First, we compared the ecological characteristics, abundance of phlebotomies and potential reservoir hosts in the peridomestic environment (100 m radius) of randomly selected houses, between two townships with high and low cutaneous leishmaniasis incidence. Second, we examined peridomestic correlates of phlebotomine abundance in all 43 houses in the higher risk township. Results The high transmission township had higher coverage of forest (23%vs. 8.4%) and shade coffee (30.7%vs. 11%), and less coffee monoculture (16.8%vs. 26.2%) and pasture (6.3%vs. 12.3%), compared to the low transmission township. Lutzomyia were more abundant in the high transmission township 2.5 vs. 0.2/trap/night. Lutzomyia longiflocosa was the most common species in both townships: 1021/1450 (70%) and 39/80 (49%). Numbers of potential wild mammal reservoirs were small, although four species were found to be infected with Leishmania (Viannia) spp. In the high transmission township, the overall peridomiciliary capture rate of L. longiflocosa was 1.5/trap/night, and the abundance was higher in houses located nearer to forest (ρ = −0.30, P = 0.05). Conclusion The findings are consistent with a domestic transmission cycle with the phlebotomies dependent on dense vegetation near the house. Objectif: Evaluer les facteurs environnementaux et ecologiques lies a la transmission de Leishmania et l’abondance du vecteur a Chaparral, Tolima-Colombie. Methodes: Nous avons d’abord, compare les caracteristiques ecologiques, l’abondance des phlebotomes et les reservoirs potentiels dans l’environnement peri-domestique (rayon de 100 m) de maisons choisies aleatoirement, entre deux zones a incidence elevee et faible de la leishmaniose cutanee. Ensuite, nous avons examine les correlats peri-domestiques de l’abondance des phlebotomes dans toutes les 43 maisons de la zone avec le risque le plus eleve. Resultats: La zone avec une transmission elevee avait une plus grande etendue de foret (23 versus 8,4%) et de plants de cafe (30,7 versus 11%) et moins de monocultures de cafe (16,8 versus 26,2%) et de pâturages (6,3 versus 12,3%), comparee a la zone avec une faible transmission. Les especes Lutzomyiaetaient plus abondantes dans la zone avec une transmission elevee: 2,5 versus 0,2/piege/nuit. Lutzomyia longiflocosaetait l’espece la plus courante dans les deux zones: 1021/1450 (70%) et 39/80 (49%). Le nombre de mammiferes sauvages reservoirs potentiels etait faible, bien que 4 especes aient ete trouvees infectees par Leishmania (Viannia) spp. Dans la zone a transmission elevee, le taux global de capture autour des domiciles de L. longiflocosaetait de 1,5/piege/nuit et l’abondance etait plus elevee dans des maisons situees pres de la foret (RR= -0,30; p = 0,05). Conclusion: Les resultats sont compatibles avec un cycle de transmission domestique ou les phlebotomes sont dependants de la vegetation dense aupres des maisons. Objetivo: Evaluar los factores ambientales y ecologicos asociados con la transmision de Leishmania y la abundancia del vector en Chaparral, Tolima-Colombia. Metodos: En primer lugar comparamos las caracteristicas ecologicas, la abundancia de flebotominas y potenciales reservorios en el medio peridomestico (radio de 100m) de casas elegidas al azar, entre dos poblados con una incidencia alta y baja de leishmaniasis cutanea. En segundo lugar, examinamos factores peridomesticos correlacionados con la abundancia de flebotominas en las 43 casas del poblado con mayor riesgo. Resultados: El poblado con una alta transmision tenia una mayor cobertura de bosque (23 versus 8.4%) y cultivo de cafe bajo sombra (30.7 versus 11%), y un menor monocultivo de cafe (16.8 versus 26.2%) y pastos (6.3 versus 12.3%), comparado con el poblado con baja transmision. Lutzomyia era mas abundante en el poblado con alta transmision (2.5 versus 0.2/trampa/noche.) Lutzomyia longiflocosa era la especie mas comun en ambos poblados: 1021/1450 (70%) y 39/80 (49%). El numero de posibles reservorios mamiferos salvajes era pequeno, aunque se encontraron 4 especies infectadas con Leishmania (Viannia) spp. En el poblado con alta transmision, la tasa de captura peridomiciliaria de L. longiflocosa era 1.5/trampa/noche, y la abundancia era mayor en casas localizadas mas cerca del bosque (ρ=-0.30, p=0.05). Conclusion: Estos hallazgos son consistentes con un ciclo de transmision domestico, y con las flebotominas dependientes de una vegetacion densa cercana a la casa.

We report 2 polymerase chain reaction (PCR)-based methods for distinguishing morphologically similar gregarine species based on amplification of variable regions of the internal transcribed spacer region of ribosomal DNA. The gregarines we investigated were Ascogregarina barretti (Vavra), A. culicis (Ross), and A. taiwanensis (Lien and Levine), parasites of the mosquitoes Ochlerotatus triseriatus (Say), Aedes aegypti (Linnaeus), and Ae. albopictus (Skuse), respectively. These 3 important vector mosquitoes often utilize the same container habitats, where larval development and infection by the parasite occurs, leaving ample opportunity for cross-species gregarine infection. Because previous studies have shown that the parasites A. culicis and A. taiwanensis variably affect fitness in both normal and abnormal mosquito hosts, distinguishing parasite infection and species is important. The task is complicated by the fact that these 2 parasite species are virtually identical in morphology, whereas A. barretti is morphologically distinct. Of the 2 PCR-based assays reported here, the first provides a rapid, sensitive, and straight- forward means of general ascogregarine detection based on a single PCR amplification. The second method provides a means of differentiation between A. culicis and A. taiwanensis based on a species-specific PCR assay. Together, these assays allow whole mosquitoes to be tested for the presence of Ascogregarina species as well as identification of both A. culicis and A. taiwanensis singly or in dual infections. Ascogregarina (Apicomplexa: Lecudinidae) contains a group of protozoan parasites that naturally infect certain insects. In mosquitoes (Diptera: Culicidae), infections have only been de- scribed from some container-breeding species (Beier and Craig, 1985). Three such species, Aedes aegypti (Linnaeus), Ae. al- bopictus (Skuse), and Ochlerotatus triseriatus(Say), are known or potential vectors of a number of arboviruses (Calisher, 1994). Each of the 3 mosquito species can naturally harbor a specific gregarine parasite that allows the host mosquito to carry out life functions relatively unaffected by its presence. The parasite is transmitted to other mosquitoes in the aquatic environment when feeding larvae ingest oocysts released by defecating or dead adult mosquitoes. Gregarine trophozoites feed intracellu- larly in the midgut epithelium and increase in size during mos- quito larval development; gametogony and sporogony in the Malphigian tubules during the pupal and early adult stages re- sult in new oocysts that are released back into the larval envi

The identity of the sandfly vectors of Leishmania braziliensis in Valle del Cauca Department, Colombia, was originally given as Lutzomyia townsendi, but then changed to L. youngi, another member of the L. townsendi series (Verrucarum group) with isomorphic females. To identify members of this series in Valle del Cauca, we analyzed the nuclear gene elongation factor-alpha (EF-alpha) and the mitochondrial gene cytochrome b (Cyt b). DNA sequences from the L. verrucarum series (L. columbiana, L. evansi and L. ovallesi) were used as outgroups. Flies from two locations on the western cordillera of the Andes were identified as L. townsendi s.s., according to male morphology and distinctive gene lineages. In the third location, on the central cordillera of the Andes, most specimens were identified as belonging to a geographical population of L. youngi, according to male morphology, an EF-alpha lineage shared with L. youngi from the Venezuelan-type locality, and a distinctive Cyt b sub-lineage. All other specimens were identified as L. youngi with the introgressed Cyt b sequences of L. townsendi. Such interspecific introgression implies that vectorial traits and ecological associations may no longer be viewed as fixed properties of different morphospecies.

Canine visceral leishmaniasis (VL), caused by Leishmania infantum (Leishmania chagasi in the New World), is a zoonotic, endemic disease in Western Europe and Latin America. The potential spreading to new regions was suggested by the appearance of canine VL among foxhounds in the US. Although the sand fly vectors in the major foci of transmission have been described, no information exists on other sand flies that could propagate the infection outside endemic areas. We evaluated the capacity of Lutzomyia shannoni (Dyar) and Lutomyia youngi (FeliciangeliMurillo), which are widely distributed in the New World, to acquire L chagasi (Cunha and Chagas) infections. A high proportion of L youngi were infected after feeding on an oligosymptomatic dog (51 per cent) or a polysymptomatic individual (95 per cent), but the intensity of infection was low (200 promastigotes/fly). L shannoni became infected only by feeding on the polysymptomatic dog, and the infection rate was lower (9 per cent) than in Lutzomyia longipalpis (36 per cent), and Lutzomyia evansi (Nunez-Tovar) (Lutz and Neiva) (38 per cent), but the intensity of infection (200 to500 promastigotes/fly) was comparable (L longipalpis) or higher (L evansi) than in the New World vectors. It is hypothesised that the presence of infected dogs in areas where L shannoni or L youngi occur could initiate new endemic cycles of VL in both South and North America.

Las leishmaniasis son endémicas en >98 países con 14 mi-llones de infectados. Leishmania sobrevive en los mamíferos aún después del tratamiento pero se desconoce su capaci-dad de persistir en piel sana e infectar vectores. Para demos-trar la migración de Leishmania (Viannia) panamensis a piel sana, su persistencia en estos sitios durante estados cróni-cos de infección y la infectividad de los parásitos persistentes para Lutzomyia longipalpis, se inocularon 10 hámsters in-tradérmicamente en pata con 2x107promastigotes de L. (V.) panamensis. Los hámsters se sacrificaron a las 13 (fase agu-da) y 53 (fase crónica) semanas post-infección. Biopsias de lesión, piel sana y otros tejidos se analizaron por reacción en cadena de la polimerasa (PCR) con el gen Hsp70 y qPCR con el gen DNA polymerase. La transmisión de los parásitos a Lu. longipalpis se determinó mediante xenodiagnóstico. To-das las muestras de fase aguda (excepto oreja contralateral) y todas las muestras de fase crónica fueron positivas, aunque la positividad en fase crónica fue menor que en fase aguda. Dos animales de fase aguda y un animal de fase crónica fue-ron infecciosos al vector, después de alimentarse sobre la lesión. No hubo ningún insecto positivo en los alimentados sobre piel sana.Se reporta por primera vez la diseminación y persistencia de L. (V) panamensis, y se confirma la persis-tencia en un periodo de 53 semanas. Sin embargo la carga parasitaria en tejidos diferentes al sitio de inóculo fue baja y no se detectó su transmisión al vector. La PCR con Hsp70 y qPCR con DNA polymerase son técnicas útiles en la determi-nación del estatus infeccioso en los hospederos vertebrados. Leishmaniasis are endemic in >98 countries with 14 million people infected. Leishmania survives in mammal hosts even after treatment but the capacity to persist in healthy skin and infect sandflies from these sites is poorly understood. To demonstrate migration of Leishmania (V.) panamensis into healty skin, persistence in these sites during chronic stages of infection and infectivity of persistant parasites to Lutzomyia longipalpis 10 hamsters were inoculated intradermally in the hind footpad, with 2x107L. (V.) panamensis promastigotes. Hamsters were sacrificed at 13 (acute phase) and 53 (chronic phase) weeks post-infection. Biopsies from lesion, healty skin and othert tissues were screened by Hsp70 polymerase chain reaction (PCR) and DNA polymerase qPCR. Transmission of parasites to sandflies was determined by xenodiagnosis. Positivity was observed in all samples of acute infection group except the contralateral ear and chronic infection group, although the percentage of positivity in chronic infection was lower than that for acute infection. Two animals of the acute infection group and one from the chronic infection group were infective to sand flies after feeding over the lesion site. No infections were found in sandflies fed from healthy skin. Dissemination and persistence of L. (V.) panamensiswas reported for first time and persisntace is confirmed for a period of 53 weeks. However, parasite load in tissues different from the inoculation site was lower and transmission to the sand fly vectors from these sites was not observed. Hsp70 PCR and qPCR are useful techniques for determining infection status of vertebrate hosts. Incluye referencias bibliográficas

We studied the reservoir competency of canines with distinct clinical presentations of Leishmania chagasi infection. The parasitologic status of asymptomatic and symptomatic dogs was determined by standard culture methods Infectivity was assessed by multiple xenodiagnoses with Lutzomyia longipalpis, over a period of 2-11 months. Asymptomatic dogs were non-infective (0 of 5) while 2 of 7 oligosymptomatic dogs infected L longipalpis, transmitting the parasites at low rates (range 0.9-5.2% of engorged flies). Polysymptomatic dogs transmitted L. chagasi more frequently (4 of 8 dogs) and reached higher infection rates (range 5.0-22.5% of engorged flies). The skin of the ear tended to be more infective to sand flies than that of the abdomen. Polymerase chain reaction hybridization (PCR-H) was a sensitive method for detection of L. chagasi, yielding the highest positive rate in serum (16 of 17 dogs) with no distinction between clinical groups. No association between skin positivity by PCR-H and infectivity to sand flies was found. The infectivity of dogs from clinically comparable groups from Colombian and Mediterranean foci differed. This may be a reflection of varied nutritional conditions or vector competency of distinct sand fly species.

The effectiveness of bednets and curtains (nylon mesh 64 per cm2) impregnated with deltamethrin at 26 mg a.i./m2 in reducing the biting nuisance caused by three phlebotomine sandfly species: Lutzomyia columbiana, Lu.lichyi and the predominant Lu.youngi (Diptera: Psychodidae), was evaluated at La Guaira, a rural settlement in Valle de Cauca near Cali, Colombia. Pairs of volunteers collected sandflies under impregnated bednets, in rooms protected by impregnated curtains or in unprotected rooms in a randomized matched design. Collections were made in three houses per night on three consecutive nights, so that each house was sampled under each of the three treatments. This routine was repeated at 2-week intervals for 6 months. There was no significant difference between the overall numbers of sandflies collected in rooms with or without impregnated curtains. Only 0.14 sandflies/man-hour were caught on human bait under impregnated bednets, significantly fewer than the numbers collected on human bait outside the nets in the same room (1.91) or in unprotected rooms (3.29). In a second set of experiments carried out in La Guaira and the neighbouring community of Jiguales, the effect of deltamethrin impregnation was evaluated by comparing numbers of sandflies collected on human bait under treated and untreated nets. Significantly fewer were collected under the impregnated nets (0.25 v. 0.69/man-hour). Wild-caught female Lu.youngi exposed to treated netting for 2 min in the laboratory all died with 24 h. The impact of deltamethrin-impregnated bednets was considered to be useful against Lu.youngi and other potential vectors of leishmaniasis in such communities.

An attempt was made to control phlebotomine sand flies biting indoors in a rural community near Cali, Colombia, using the residual insecticide "K-Othrine" (deltamethrin) sprayed on the inside walls of houses. Twelve houses were divided into matched pairs based on physical characteristics, one house in each pair being left untreated while the inside walls of the other were sprayed with 1% deltamethrin at a concentration of 500 mg a.i./m2. Sand flies were sampled each week using protected human bait and sticky trap collections for four months after spraying. The number of sand flies (Lutzomyia youngi) collected on sticky traps was significantly lower (P = 0.004) in the untreated houses than in the treated ones with which they were matched. This difference was not significant for L. columbiana; the other anthropophilic species were not present in large numbers. The numbers collected on human bait in treated and untreated houses were not significantly different for either species. Activity of the insecticide as determined by contact bioassays remained high throughout the study and failure to control the insects was attributed to two factors: the tendency of sand flies to bite before making contact with the insecticide and the fact that the number of sand flies that entered houses represented a relatively small proportion of the population in the wooded areas surrounding the settlement in the study.

The repellency and insecticidal efficacy of Nopikex, a soap formulation containing 20% diethyl toluamide and 0.5% permethrin, was evaluated against a laboratory colony of phlebotomine sand flies (Lutzomyia longipalpis). The repellency of Nopikex soap was also compared with that of a placebo soap against another species (Lu. youngi) in a forest near Tulua, Valle del Cauca, Colombia. In laboratory trials of the soap, no reduction in repellency was seen 4 hr after application, but within 8 hr, repellency decreased significantly to 67.0% of the initial value (P < 0.05) based on calculations of the coefficient of protection (CP). Under field conditions, the soap gave up to 100% protection immediately after application, but within 4 hours its CP value had decreased to a median value of only 44.3%. The placebo soap was also found to be somewhat repellent when compared with no treatment, giving a median CP value of 67.7 immediately after application. No significant mortality was seen in sand flies within 24 hr of exposure to the soap in the laboratory, even in those that had fed on protected volunteers.

Diverse taxonomical and molecular studies suggest that Lutzomyia longipalpis , main vector of visceral leishmaniasis in Latin America, is a complex of species widely distributed throughout the continent and adapted to different habitats.To carry out entomological surveillance in the area of influence of the Miel I Hydroelectric Plant.Adhesive traps were used in a transect covering an area of approximately 400 km for the capture of insects, which were then identified using the Young and Duncan taxonomical key.This study reports the presence of Lutzomyia longipalpis in the municipalities of Norcasia at an altitude of 392 masl, and in Marquetalia at 1,387 masl.We suggest that the increase in the geographical and altitudinal distribution could be related to the existence of the Lu. longipalpis species complex, or to environmental factors, such as the rise in temperature due to global climate changes, which create the establishment of Lu. longipalpis , generating a new epidemiological risk for new visceral leishmaniasis foci in the country.

Environmental risk factors for cutaneous leishmaniasis were investigated for the largest outbreak recorded in Colombia. The outbreak began in 2003 in Chaparral, and in the following five years produced 2,313 cases in a population of 56,228. Candidate predictor variables were land use, elevation, and climatic variables such as mean temperature and precipitation. Spatial analysis showed that incidence of cutaneous leishmaniasis was higher in townships with mean temperatures in the middle of the county's range. Incidence was independently associated with higher coverage with forest or shrubs (2.6% greater for each additional percent coverage, 95% credible interval [CI] = 0.5-4.9%), and lower population density (22% lower for each additional 100 persons/km(2), 95% CI = 7-41%). The extent of forest or shrub coverage did not show major changes over time. These findings confirmed the roles of climate and land use in leishmaniasis transmission. However, environmental variables were not sufficient to explain the spatial variation in incidence.

Introducción. A pesar de que la leishmaniasis cutánea canina ha sido reportada en varios focos de Sudamérica, no existe información publicada de Colombia. Objetivo. Se reportan dos casos hallados en la región de la costa Pacífica de este país, que se presentaron como una úlcera escrotal única en un perro y como dos úlceras en la cara externa de la oreja en un segundo individuo. Materiales y métodos. Los parásitos fueron aislados por cultivo en medio de Senekjie e identificados empleando anticuerpos monoclonales. La capacidad de los perros para transmitir parásitos a los flebótomos vectores (Lutzomyia trapidoi, Lutzomyia gomezi, Lutzomyia longipalpis, Lutzomyia youngi) se ensayó permitiendo que los insectos se alimentaran sobre el borde de las lesiones. Resultados. Ambos aislamientos se identificaron como Leishmania (Viannia) braziliensis. No se detectaron infecciones durante la disección de los flebótomos alimentados. Una sola inyección peri- y sub-lesional de 1-2 ml de antimonio pentavalente en el perro con las lesiones auriculares resultó en la curación clínica a las 6 semanas post-tratamiento. Conclusiones. Estas observaciones sugieren que aunque los perros son susceptibles a L. braziliensis, su competencia como reservorio podría ser baja. Sin embargo, si estudios posteriores demuestran que los caninos tienen capacidad de reservorio para especies de L. Viannia, el tratamiento local de las lesiones podría ser una estrategia factible para disminuir el riesgo de infección humana en el peridomicilio, sin necesidad de sacrificar a los perros infectados. Introduction. Although canine cutaneous leishmaniasis has been reported in several foci of South America, no published information from Colombia is available. Objective. We report on two cases found in the Pacific coast region of this country, which presented as a single scrotal ulcer in one dog, and two ulcers on the external surface of the ear in a second dog. Materials and methods. Parasites were isolated by culture in Senekjie’s culture medium and identified using monoclonal antibodies. The capacity of these dogs to transmit the parasites to sand fly vectors (Lutzomyia trapidoi, Lutzomyia gomezi, Lutzomyia longipalpis, Lutzomyia youngi) was tested by allowing the flies to feed on the lesion borders. Results. Both isolates were identified as Leishmania (Viannia) braziliensis. No infections were detected upon dissection of engorged flies. A single peri-and sub-lesional injection of 1-2 ml of pentavalent antimony in the dog with ear lesions resulted in clinical cure 6 weeks post-treatment. Conclusions. These observations suggest that although dogs are susceptible to L. braziliensis, their reservoir competence could be low. However, if further studies indicate that canines are capable reservoir hosts of L. Viannia spp., the local treatment of lesions could become a feasible approach to diminish the risk of human infection in the peridomestic setting, without sacrificing infected dogs.

Background. American cutaneous leishmaniasis is considered to be a zoonotic disease transmitted by sand flies that feed on infected sylvatic mammals. However, the "domestication" of transmission and the increase in treatment failure with antimonial drugs have raised the suspicion of anthroponotic transmission of American cutaneous leishmaniasis. Methods. The objective of the present study was to explore the potential of humans as a source of infection for sand flies. Biological (xenodiagnosis and culture) and molecular (polymerase chain reaction/Southern blot) detection methods were used to evaluate peripheral-blood monocytes and tissue fluids from sites accessible to sand flies from 59 adult patients with parasitologically confirmed American cutaneous leishmaniasis. Results. Overall, 44.1% of patients (26/59) presented biological and/or molecular evidence of Leishmania parasites in normal skin, peripheral-blood monocytes, lesion scars, or lesion border (by xenodiagnosis) before (18/ 59 [30.5%]) or after (10/27 [37.0%]) treatment. Leishmania parasites were cultured from the unaffected skin of 2 (3.6%) of 55 patients, and xenodiagnosis gave positive results for 5 (8.8%) of 57 patients before treatment. Conclusions. The presence of Leishmania parasites in the unaffected skin and peripheral-blood monocytes of a high proportion of patients even after treatment and the acquisition of infection by sand flies support the plausibility of anthroponotic transmission of American cutaneous leishmaniasis.

The infection rates and development of Leishmania chagasi in two sandfly species, Lutzomyia evansi and Lutzomyia longipalpis, were evaluated under natural and experimental conditions. Natural infection rates of Lu. evansi in San Andres de Sotavento (Colombia) and Montanas de Peraza (Venezuela) (0.05 and 0.2%, respectively) were similar to those previously recorded for this species in Colombia and Venezuela and for Lu. longipalpis in many foci of American Visceral Leishmaniasis (AVL). Both sand fly species were able to support the development of two Colombian strains of L. chagasi experimentally acquired from dogs, hamsters or membrane feeders. However, the experimental infection rates and the sequence of parasite development in the guts of these sand flies revealed that parasite colonisation, differentiation, migration and attachment were more frequent and uniform in Lu. longipalpis than in Lu. evansi. This is consistent with a more recent association between L. chagasi and Lu. evansi, and these results might help to explain the irregularity of AVL outbreaks in foci where Lu. evansi has been reported as the sole vector.

Travi, B. L., Osorio, Y., Guarin, N., and Cadena, H. 1998. Leishmania dog with visceral leishmaniasis and was subsequently reinoculated in (Leishmania) chagasi: Clinical and parasitological observations in an opossum. Parasites recovered from this animal were cultured in experimentally infected Didelphis marsupialis, reservoir of New NNN medium and in the U937 promonocytic cell line. A total of 13.5 World visceral leishmaniasis. Experimental Parasitology 88, 73–75. 3 107 amastigotes (am) derived from infected U937 cells or 5.6 3

The sandfly Lutzomyia evansi from a focus of visceral leishmaniasis in northern Columbia was reared and maintained under laboratory conditions for five generations. The average time for total development was 41.9 days (range = 35.1-49.6) at 25 degrees C and 89-95% of relative humidity. The mean number of eggs laid was lower in laboratory bred females either in pots (13.2 eggs/female) or vials (29.9 eggs/female) than in wild caught females (33.4 eggs/female). Immature mortality, mainly due to fungal and mite contamination, was higher during the first two instars than in the remaining immature stages. Adults were robust and healthy although difficult to feed on hamster or chick skin membrane. In summary, Lu. evansi is a colonizable species but requires specific conditions.

In Colombia, the entomopathogenic fungus Beauveria bassiana (Deuteromycotina: Hyphomycetes) is widely used to control the coffee berry borer Hypothenemus hampei (Coleoptera: Scolytidae) in coffee plantations. Recent studies suggested that this fungus is also pathogenic to several important vectors of disease, including Phlebotomus papatasi and Lutzomyia longipalpis (Diptera: Psychodidae). The present study evaluated the use of B. bassiana as a potential biological control agent against phlebotomine sand flies in Colombian coffee plantations. Histopathologic examination indicates that B. bassiana is unable to infect sand flies under natural conditions, although dead sand flies were shown to be readily infected. In addition, laboratory bioassays where flies were exposed to the fungus applied onto coffee plants (though not filter paper) showed lower mean survival times than the control.

A survey was made of the phlebotomine sandfly fauna of La Guaira, a village with coffee plantations near Cali, Colombia, from which cases of American cutaneous leishmaniasis had been reported due to Leishmania (Viannia) panamensis and Le. (V.) braziliensis. Among six species of sandfly collected on human bait, Lutzomyia youngi was most important in terms of biting nuisance. Lu.columbiana, Lu.lichyi and Lu.scorzai as well as Lu.youngi adults occurred throughout the year. Sandfly man-biting activity occurred throughout the night and was highest within 2 h of sunset. Despite its abundance in nocturnal samples, Lu.youngi was rarely taken in diurnal resting site collections. In contrast, Lu.lichyi was collected on tree-trunks during the day in large numbers and was the only species biting in daylight. The implications of these and other findings for leishmaniasis control measures in La Guaira are considered.

We examined changes in the phlebotomine fauna resulting from human intervention in a tropical dry forest of Northern Colombia where visceral and cutaneous leishmaniases are endemic. A natural forest reserve (Coloso) and a highly degraded area (San Andres de Sotavento [SAS]) were sampled monthly for 8 mo using Shannon traps, sticky traps, and resting-site collections. Overall abundances were higher in Coloso (15,988) than in SAS (2,324). and species richness of phlebotomines was greater in the forest reserve (11 species) than in the degraded habitat (seven species). Fisher alpha, a measure of diversity, reinforced this trend. Both sand fly communities were dominated by Lutzomyia evansi (Nuoez-Tovar), vector of Leishmania chagasi (Cunha & Chagas), representing 92 and 81% of all captures in Coloso and SAS, respectively. Lutzomyia longipalpis (Lutz & Neiva), the common vector of visceral leishmaniasis, accounted for 4-7% of the sand fly community. Lutzornyia panamensis (Shannon) and Lutzomya gomezi (Nitzulescu), putative vectors of Leishmania braziliensis (Vianna), had low abundances at both study sites. The zoophilic species Lutzomyia cayennensis (Floch & Abonneuc) and Lutzomyia trinidadensis (Newstead) were present in variable numbers according to trapping methods and site. Habitat degradation negatively affected sand fly communities, but medically important species were able to exploit modified environments, thereby contributing to Lishmania endemicity.

Background The location of the microhabitats where immature phlebotomine sand flies of the genus Lutzomyia develop is one of the least-known aspects of this group of medically important insects. For this reason strategies of source reduction approach for their control have not been possible in contrast to other insect vectors (such as mosquitoes), because their juvenile stages in terrestrial microhabitats is difficult to detect. Methods Direct examination of soil samples, incubation of substrates and the use of emergence traps were the methods used to identify juvenile stages in 160 soil samples from urban and forest habitats within the foci of Leishmania transmission in Colombia. Immatures collected were identified subsequent from the rearing and emergence of adults using taxonomic keys or the analysis of the mitochondrial marker cytochrome oxidase I. Plant species associated with the natural breeding sites were identified and physicochemical properties of the soils were analyzed. Results A total of 38 (23.7%) sampling sites were identified as breeding sites, 142 phlebotomine sand flies were identified, belonging to 13 species of the genus Lutzomyia and two of Brumptomyia. The greatest numbers of immature were found within the tabular roots (51 immature sand flies from eight positive sites) and bases of trees (35 immature sand flies from 11 sites). The characterization and presence of the tree species (mainly Ceiba pentadra, Anacardium excelsum, Pseudosamanea guachapale) and the physicochemical properties (relative humidity and carbon/nitrogen ratio) of the soils associated with these breeding sites are significant factors in explaining the diversity and abundance of phlebotomine sand flies. Conclusions Immature phlebotomine sand flies of the genus Lutzomyia in Colombia can be found in a wide variety of breeding sites rich in organic matter, high relative humidity and are associated with a typical vegetation of each locality. These results provide new perspectives for the study of the ecology of the genus Lutzomyia in Colombia and the development of vector control strategies.