Browsing by Author "Alten B."

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    Seasonal Dynamics of Phlebotomine Sand Fly Species Proven Vectors of Mediterranean Leishmaniasis Caused by Leishmania infantum
    (Public Library of Science, 2016) Alten B.; Maia C.; Afonso M.O.; Campino L.; Jiménez M.; González E.; Molina R.; Bañuls A.L.; Prudhomme J.; Vergnes B.; Toty C.; Cassan C.; Rahola N.; Thierry M.; Sereno D.; Bongiorno G.; Bianchi R.; Khoury C.; Tsirigotakis N.; Dokianakis E.; Antoniou M.; Christodoulou V.; Mazeris A.; Karakus M.; Ozbel Y.; Arserim S.K.; Erisoz Kasap O.; Gunay F.; Oguz G.; Kaynas S.; Tsertsvadze N.; Tskhvaradze L.; Giorgobiani E.; Gramiccia M.; Volf P.; Gradoni L.
    Background: The recent geographical expansion of phlebotomine vectors of Leishmania infantum in the Mediterranean subregion has been attributed to ongoing climate changes. At these latitudes, the activity of sand flies is typically seasonal; because seasonal phenomena are also sensitive to general variations in climate, current phenological data sets can provide a baseline for continuing investigations on sand fly population dynamics that may impact on future scenarios of leishmaniasis transmission. With this aim, in 2011–2013 a consortium of partners from eight Mediterranean countries carried out entomological investigations in sites where L. infantum transmission was recently reported. Methods/Principal Findings: A common protocol for sand fly collection included monthly captures by CDC light traps, complemented by sticky traps in most of the sites. Collections were replicated for more than one season in order to reduce the effects of local weather events. In each site, the trapping effort was left unchanged throughout the survey to legitimate inter-seasonal comparisons. Data from 99,000 collected specimens were analyzed, resulting in the description of seasonal dynamics of 56,000 sand flies belonging to L. infantum vector species throughout a wide geographical area, namely P. perniciosus (Portugal, Spain and Italy), P. ariasi (France), P. neglectus (Greece), P. tobbi (Cyprus and Turkey), P. balcanicus and P. kandelakii (Georgia). Time of sand fly appearance/disappearance in collections differed between sites, and seasonal densities showed variations in each site. Significant correlations were found between latitude/mean annual temperature of sites and i) the first month of sand fly appearance, that ranged from early April to the first half of June; ii) the type of density trend, varying from a single peak in July/August to multiple peaks increasing in magnitude from May through September. A 3-modal trend, recorded for P. tobbi in Cyprus, represents a novel finding for a L. infantum vector. Adults ended the activity starting from mid September through November, without significant correlation with latitude/mean annual temperature of sites. The period of potential exposure to L.infantum in the Mediterranean subregion, as inferred by adult densities calculated from 3 years, 37 sites and 6 competent vector species, was associated to a regular bell-shaped density curve having a wide peak center encompassing the July-September period, and falling between early May to late October for more than 99% of values. Apparently no risk for leishmaniasis transmission took place from December through March in the years considered. We found a common pattern of nocturnal females activity, whose density peaked between 11 pm and 2 am. Conclusions: Despite annual variations, multiple collections performed over consecutive years provided homogeneous patterns of the potential behavior of leishmaniasis vectors in selected sites, which we propose may represent sentinel areas for future monitoring. In the investigated years, higher potential risk for L. infantum transmission in the Mediterranean was identified in the June-October period (97% relative vector density), however such risk was not equally distributed throughout the region, since density waves of adults occurred earlier and were more frequent in southern territories. © 2016 Alten et al.
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    Vector and reservoir surveillance study in a canine and human leishmaniasis endemic area in most western part of Turkey, Karaburun
    (Elsevier B.V., 2019) Karakuş M.; Arserim S.K.; Erişöz Kasap Ö.; Pekağırbaş M.; Aküzüm D.; Alten B.; Töz S.; Özbel Y.
    Leishmaniasis is an arthropod borne disease that is endemic in 102 countries and one and half million new cases are reported each year. Sand flies are the one and only proven vectors of the disease and dogs are the main reservoirs in urban areas. Karaburun peninsula is located in most western part of Turkey and is reported to be an endemic area for human and canine leishmaniasis. The most recent study was undertaken more than 15 years ago in The peninsula and no clear data available for vectors or reservoirs. Thus, we aimed to update the information regarding sand fly diversity, infection status of reservoirs and vectors in the study area. Sand flies were collected using CDC light traps at 13 different sites of Karaburun and species identification was made using previously published keys. Monospecific pools were generated using midguts with blood retention and were screened for the presence of Leishmania spp. DNA by molecular techniques. A non-invasive conjunctival swab sampling was performed to identify the infection status among reservoirs and species typing of the causative agent was also undertaken using ITS1 PCR. Three out of 30 pools were found positive for Leishmania infantum that were generated using guts of Phlebotomus tobbi (n:36). Among all sampled dogs (44) and cats (19), 11 and one of them were found positive for L. infantum, respectively. There was a decrease in the number of P. papatasi during the study period, while increase was observed in the number of P. tobbi. The presence of proven vectors and reservoirs as well as Leishmania DNA in cats was shown in the present study. Sand fly fauna is updated and Leishmania DNA presence in cats was reported in the study area for the first time. © 2018 Elsevier B.V.
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    The initial detection of Toscana virus in phlebotomine sandflies from Turkey
    (Blackwell Publishing Ltd, 2020) Özbel Y.; Oğuz G.; Arserim S.K.; Erişöz Kasap Ö.; Karaoglu B.; Yilmaz A.; Emanet N.; Günay F.; Hacioğlu S.; Demirok M.C.; Töz S.; Alten B.; Nalçaci M.; Özkul A.; Ergünay K.
    Toscana virus (TOSV) is a prominent arthropod-borne viral agent of human central nervous system infections occurring in the Mediterranean region. The main transmission route to susceptible individuals involves sandflies as vectors. Despite several reports revealing widespread TOSV activity in Turkey, vectors remained unidentified. A sandfly field survey was carried out in five provinces in Central, Southeast and Mediterranean Anatolia in 2017 to identify TOSV and related sandfly-borne phleboviruses and Leishmania parasites, with evidence for circulation in the region. A total of 7136 sandfly specimens, collected via standard methods, were evaluated in 163 pools. TOSV was detected in 11 pools (6.7%), comprising Phlebotomus major sensu lato, Sergentomyia dentata and Phlebotomus papatasi species. TOSV partial L and S segment sequences were characterized, that phylogenetically clustered with local and global genotype A strains. An amino acid substitution outside the conserved motifs of the viral polymerase, also present in previous TOSV sequences in endemic regions, was observed. Leishmania tropica was detected in a single pool of Ph. sergentii (0.6%). This is the first report of TOSV in sandflies from Turkey, and this study further provides evidence for additional sandfly species with the potential to transmit TOSV. © 2020 The Royal Entomological Society