Exotic vector-borne diseases are gaining attention at the expense of leishmaniasis.
BackgroundThe 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 FindingsA 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.ConclusionsDespite 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 ri...
Sand fly saliva plays an important role in Leishmania transmission. We characterized the host antibody response to saliva from 3 sand fly species. Specific IgG was observed in sera from experimentally bitten mice as well as in sera from individuals living in the endemic area of Leishmania tropica in Sanliurfa, Turkey. Sera of Sanliurfa inhabitants showed high IgG levels against saliva of Phlebotomus sergenti and P. papatasi, the 2 most abundant sand fly species in this area, but did not react with saliva of the New World sand fly, Lutzomyia longipalpis. Patients with active Le. tropica lesions possessed significantly higher anti-P. sergenti IgG levels than the healthy individuals from the same place while anti-P. papatasi IgG levels were equal in both groups. Major protein bands in P. papatasi and P. sergenti saliva reacted with both, human and mice sera; in P. papatasi, however, mouse IgG recognized preferentially the 42 kDa protein band while the human IgG reacted strongly with the 30 kDa band. Our data suggest that the antibody response to sand fly saliva could be used for monitoring the exposure of humans and other hosts to sand flies and might be used as a marker of risks for Leishmania transmission in endemic areas.
Background The determination of the acceptance of the COVID‐19 vaccine by the health personnel will also be a guide for the upcoming vaccination studies. The aim of this study is to determine the acceptance status of COVID‐19 vaccine amongst healthcare professionals. Materials and methods A total of 1138 healthcare workers participated in this cross‐sectional study between 17th and 20th of September, 2020. The questionnaire, which was delivered via social media, was filled out by the participants over "Google Forms." Results As a result of the questionnaire, 68.6% of the healthcare professionals stated that they could be vaccinated. Men, students, the younger age group, and those who had a previous flu shot were all willing to get the COVID‐19 vaccine. Conclusions Efforts to increase the knowledge of healthcare professionals about the new vaccine and to eliminate their doubts and concerns are important.
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Human visceral leishmaniasis (VL) caused by L. infantum and cutaneous leishmaniasis (CL) caused by L. tropica and L. infantum have been reported in Turkey. L. infantum is also responsible for canine leishmaniasis (CanL) and it is widely common in the country. The main aim of the present study was to design a real-time PCR method based on the internal transcribed spacer 1 (ITS1) region in the diagnosis of all clinical forms of leishmaniasis in Mediterranean, and to identify the species directly from clinical samples. Totally, 315 clinical specimens, human/canine visceral (blood, bone marrow, lymph node) and cutaneous (lesion aspiration) samples, and 51 Turkish Leishmania isolates typed by isoenzymatic method were included in the study. For optimization, DNA samples of the 34 strains were amplified by conventional ITS1-PCR and then sequenced for designing the primers and probes, allowing the species identification. Following the validation with the isolates, the test was applied on clinical samples and melting temperatures were used for genotyping. A group of PCR products were further sequenced for confirmation and assigning the inter- and intraspecies heterogeneity. The diagnosis of leishmaniasis is successfully achieved by the new real-time PCR method, and the test identified 80.43% of human and canine VL samples as L.infantum and 6.52% as L.tropica; 52.46% of CL samples as L. infantum and 26.90% as L. tropica. In 13.04% of visceral and 20.62% of cutaneous samples, two peaks were observed. Hovewer, the higher peak was found to be concordant with the sequencing results in 96.96%, in terms of species identification. The real-time ITS1 PCR assay clearly identified the leishmanial species in 81.58% of all clinical samples. Genotypic variations of Leishmania parasites in Turkey within species and intraspecies were observed, and L. tropica is also found as causative agent of human and canine VL in Turkey.
Currently available methods for the diagnosis of cutaneous leishmaniasis (CL) have low sensitivities or are unable to quantify the number of viable parasites. This constitutes a major obstacle for the diagnosis of the disease and for the study of the effectiveness of treatment schedules and urges the development of improved detection methods. In this study, quantitative nucleic acid sequence-based amplification (QT-NASBA) technology was used to detect and quantify Leishmania parasites in skin biopsy samples from CL patients. The assay is based on the detection of a small subunit rRNA (18S rRNA), which may allow for the detection of viable parasites. The QT-NASBA assay was evaluated using in vitro-cultured promastigotes and amastigotes and 2-mm skin biopsy samples from Old and New World CL patients. The study demonstrated that the lower detection limit of the QT-NASBA was two parasites per biopsy sample. Parasites could be quantified in a range of 2 to 11,300,000 parasites per biopsy sample. The QT-NASBA could detect levels of parasites 100-fold lower than those detected by conventional PCR. Test evaluation revealed that the QT-NASBA had a sensitivity of 97.5% and a specificity of 100% in the present study. The QT-NASBA is a highly sensitive and specific method that allows quantification of both Old and New World Leishmania parasites in skin biopsy samples and may provide an important tool for diagnosis as well as for monitoring the therapy of CL patients.
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