Sand Fly-borne Diseases Research Articles

Phlebotomine sand flies on the crossroads of Anatolia: transmitted diseases and vectors

The Western Palearctic (WP) is composed of Europe, Middle East and North Africa. In this territory, the Mediterranean Sea, and the land under the influence of the Mediterranean Sea is the most important geographical character for both migration and dispersion of organisms; especially for invertebrates including sand flies. Anatolia (Asia-Minor) takes place on the crossroads of this area and these events. The phlebotomine sand flies (Diptera: Psychodidae, Phlebotominae) are vectors of several infectious pathogens causing leishmaniases and arbovirus infections due to phleboviruses. Several of these diseases have wide geographical distributions in the WP, and give rise to occasional epidemic outbreaks. In numerous countries, increasing risk factors are making sand fly-borne diseases a major public and veterinary health problem. Many studies on phylogenetic relationship among sand fly taxa, their distribution, population structure and diseases of phlebotomine species have been already published, but there are still many gaps waiting to be filled up in, especially, Anatolia. In this point, scientists have to discuss some deficiencies under cover of geography, history and phylogenetic studies to understand the mechanisms of distribution of both sand fly species and their pathogens in Anatolia. In this presentation, updates in distribution of sand fly species with state of art maps of EU-VBORNET project, possible new species, leishmaniasis and phleboviruses epidemiology will be discussed with an emphasis on several studies performed by our group between 2000 and present in Anatolia. Studies were supported by EU-FP7 Edenext project, HU-Scientific Research Foundation and Turkish Scientific and Technical Research Council.

Combining climatic projections and dispersal ability: a method for estimating the responses of sandfly vector species to climate change.

BackgroundIn the Old World, sandfly species of the genus Phlebotomus are known vectors of Leishmania, Bartonella and several viruses. Recent sandfly catches and autochthonous cases of leishmaniasis hint on spreading tendencies of the vectors towards Central Europe. However, studies addressing potential future distribution of sandflies in the light of a changing European climate are missing.MethodologyHere, we modelled bioclimatic envelopes using MaxEnt for five species with proven or assumed vector competence for Leishmania infantum, which are either predominantly located in (south-) western (Phlebotomus ariasi, P. mascittii and P. perniciosus) or south-eastern Europe (P. neglectus and P. perfiliewi). The determined bioclimatic envelopes were transferred to two climate change scenarios (A1B and B1) for Central Europe (Austria, Germany and Switzerland) using data of the regional climate model COSMO-CLM. We detected the most likely way of natural dispersal (“least-cost path”) for each species and hence determined the accessibility of potential future climatically suitable habitats by integrating landscape features, projected changes in climatic suitability and wind speed.Results and Relevance Results indicate that the Central European climate will become increasingly suitable especially for those vector species with a current south-western focus of distribution. In general, the highest suitability of Central Europe is projected for all species in the second half of the 21st century, except for P. perfiliewi. Nevertheless, we show that sandflies will hardly be able to occupy their climatically suitable habitats entirely, due to their limited natural dispersal ability. A northward spread of species with south-eastern focus of distribution may be constrained but not completely avoided by the Alps. Our results can be used to install specific monitoring systems to the projected risk zones of potential sandfly establishment. This is urgently needed for adaptation and coping strategies against the emerging spread of sandfly-borne diseases.

Sandflies in the Greater Athens region, Greece.

During the period from May to October 1992, a survey of phlebotomine sandflies was conducted in the Greater Athens region where cases of human and canine leishmaniasis occur. Using castor-oil paper traps, a total of 3015 sandflies were caught. Of the identified specimens, 1002 (34.1%) were Phlebotomus neglectus, 541 (18.4%) were P. papatasi, 182 (6.2%) were P. tobbi, 50 (1.7%) were P. simici, 30 (1.0%) were P. alexandri, 3(0.4%) were P. sergenti and 1122 (38.2%) were Sergentomyia minuta. The seasonal activity of most Phlebotomus species was bimodal, while that of S. minuta was unimodal. The population density of sandflies varied significantly in different localities; it was low in most of the stations and high in some stations in the outskirts. Among the potential vectors of Leishmania spp., P. neglectus and P. Papatasi were the most widespread species. The former species showed high density in 12 of the 70 sampled stations, while the latter in only 4. Hence, the risk of transmission of sandfly-borne diseases is still present in the Greater Athens region.