Leishmaniasis vectors in the environment of treated leishmaniasis cases in Spain.

Transmission of leishmaniasis in endemic areas is characterized by microfocality related to the presence of the vector. Most entomological studies in southwestern Europe have focused on sylvatic areas and town outskirts, very few have sampled town or urban centres, and no survey has investigated inside households. The aim of this study was to determine the sand fly species diversity and vector density in the surroundings of human leishmaniasis cases compared with environments in which there was no association. Sand flies were captured in 26 households associated with recently treated leishmaniasis patients, 15 neighbouring houses without associated cases, and in others environments. Overall 7495 sand flies belonging to six species were captured. The highest sand fly density was found in farmhouses where there is a great availability of blood sources and breeding sites. In the environment of human leishmaniasis cases, Sergentomyia minuta was the most prevalent species followed by Phlebotomus perniciosus. Nevertheless, lower Leishmania infantum infection rates and lower intensity of infection were detected in S. minuta sand flies than in P. perniciosus. The density of P. perniciosus in households with recently treated leishmaniasis patients varies between 0 and 108 sand flies per light trap/night, with the maximum values corresponding to farmhouses. This species appears to be adapted to both indoors and outdoors domestic biotopes, including urban households.

Seasonal dynamics of phlebotomine sand flies and autochthonous transmission of Leishmania infantum in high-altitude ecosystems in southern Spain.

Leishmaniasis is a vector-borne disease transmitted by sand flies. A dozen species have been involved in the transmission of Leishmania infantum in the Mediterranean region. Climate change may alter sand fly distribution at particular altitudes and latitudes. The objective of this study was to interrogate the existence of stable populations of sand flies in high-altitude ecosystems and evaluate if these populations are enough to support autochthonous transmission of leishmaniasis. These altitudinal conditions can be found in Sierra Nevada (southern Spain). Therefore, we have determined the sand fly population dynamics in different biotopes located at elevations above 1,300 m a.s.l. and searched for evidence of leishmaniasis transmission. Five collecting sites above 1,300 m a.s.l. containing large livestock concentrations were selected. Sand flies were caught using CDC light traps from May to November, annually from 2008 to 2013, and these were morphologically identified. Association between sand fly density or presence and temperature/humidity was estimated by linear and logistic regression, respectively. Leishmania infantum detection in female sand flies was performed by PCR. Diagnosis of canine leishmaniasis (CanL) was carried out by indirect immunofluorescence and PCR. A total of 2,973 specimens of 5 sand fly species were collected from June to October. Phlebotomus perniciosus was the most frequent (100%), abundant (80.1%) and densest species (9.8 sand flies/trap). The minimum temperature on the day of capture was the most important variable factor for sand fly presence and P. perniciosus density. An increase in altitude showed a negative effect over the sand fly diversity and activity period, driving changes in seasonal dynamics similar to those reported by latitudinal changes. CanL prevalence was 23%, a similar rate to previous surveys carried out on randomly selected dogs from towns in southern Spain. A successful host-vector-pathogen network was found at this altitude characterised by 9.9% L. infantum infection rate in non-blood fed P. perniciosus and Phlebotomus ariasi females and high CanL prevalence that entails an increase in the leishmaniasis risk area driven by sand fly colonization.

Phlebotomine sandflies (Diptera, Phlebotomidae) of Lanzarote Island (Canary Islands, Spain): Ecological survey and evaluation of the risk of Leishmania transmission.

Phlebotomine sandflies are natural vectors of Leishmania spp. and their expansion throughout has been evidenced in the last few years due to the global warming and changes in human behavior, worsening leishmaniasis problem. However, phlebotomine sandflies have been captured in small numbers on the Canary Islands, particularly on the island of Lanzarote, where only one limited survey was carried out almost thirty years ago. The proximity of this island to Morocco, in addition to the high number of tourists, sometimes accompanied by their dogs, from leishmaniasis endemic regions, highlights the importance of studying the sandfly fauna on this island in order to determine the transmission risk of leishmaniasis Thirty-eight sampling sites spread across the island were studied, and ecological features were gathered to identify the ecological traits associated to the presence of sandflies. Only 85 sandfly specimens were captured (1.18/m2) with the following species distribution: Sergentomyia minuta (0.15 specimens/m2), which was reported for the first time on this island, and S. fallax (1.03/m2). Sandfly captured were achieved in only 7 out of 38 stations. No specimen of the Phlebotomus genus was captured and given that none of the species captured has been demonstrated vectors of human pathogenic Leishmania and considering that they were captured in low frequency and density, it can be concluded that the current leishmaniasis transmission risk is null.

Topical Treatment of Leishmania tropica Infection Using (-)-α-Bisabolol Ointment in a Hamster Model: Effectiveness and Safety Assessment.

There is currently no reliable treatment for the management of cutaneous leishmaniasis, and intralesional antimonial injections remain the main treatment. The present work aims at evaluating the antileishmanial effectiveness and safety of (-)-α-bisabolol (1) in a novel topical formulation on a cutaneous leishmaniasis model involving Leishmania tropica-infected Syrian hamsters. The topical treatment with 1 reduced lesion thickness to 56% at 2.5%, showing a higher efficacy than the reference control, meglumine antimoniate. Other regimens (ointment at 1% and 5% and oral treatment at 200 mg/kg) reduced the footpad thickness as well. The skin parasite load decreased after the experiment in all treatment groups, particularly in those animals treated with the 2.5% formulation (83.2%). Treatment with (-)-α-bisabolol at different concentrations or through an oral route did not lead to the appearance of toxicity or side effects in healthy hamsters or infected animals. Therefore, topical (-)-α-bisabolol was more effective than meglumine antimoniate in this cutaneous leishmaniasis model without showing toxicity effects on the hamsters. These results are of great interest and might be used for the development of alternatives for the treatment of cutaneous leishmaniasis, either in monotherapy or in combination with other drugs whose skin permeability could be enhanced by this sesquiterpene.