Postgraduate Program in Public Health, School of Public Health, University of São Paulo-USP, São Paulo, Brazil.
PECET (Program for the Study and Control of Tropical Diseases) Faculty of Medicine, Universidad de Antioquia, Medellin, Colombia.
PLoS Negl Trop Dis. 2023 May 11;17(5):e0011316. doi: 10.1371/journal.pntd.0011316. eCollection 2023 May.
The transmission dynamics of leishmaniasis are complex. There is also a lack of information about the ecological relationships between the vector/host/parasite at a more local and specific level. The Andean region concentrates more than 50% of Colombia's cutaneous leishmaniasis (CL) cases. The study of the ecological interactions of sand flies through the identification of blood sources has provided information on the female's opportunistic behavior, feeding on various hosts. Therefore, this study aimed to determine sand flies' ecological interactions with Leishmania parasites and their blood sources in an endemic area of CL.
A total of 4,621 sand flies were collected, comprising 20 species, in which the most abundant were Nyssomyia yuilli yuilli (55.4%), Psychodopygus ayrozai (14.5%) and Ps. panamensis (13.4%). Sequences of 12S gene fragment were analyzed using the BLASTn search tool. Blood-meal source identification was successfully performed for 47 sand flies, detecting seven vertebrate species, human and armadillo being the most frequent. Leishmania DNA was amplified in four female pools, constituted by Ny. yuilli yuilli and Ps. ayrozai, and the identification through RFLP detected Leishmania (Viannia) panamensis in the positive pools.
The interactions between the sand fly species, local mammalian fauna and the Leishmania parasite in this active focus of CL, provide evidence of the potential role of two different species in the maintenance of the parasite transmission, important information for the understanding of the ecoepidemiology and transmission dynamics of the disease in Andean endemic areas. However its necessary further evaluations of the vector and host competence in the transmission and maintenance of Leishmania spp, in these complex and diverse areas.
利什曼病的传播动力学较为复杂。在更局部和特定的层面上，有关媒介/宿主/寄生虫之间生态关系的信息也较为缺乏。安第斯地区集中了哥伦比亚 50%以上的皮肤利什曼病（CL）病例。通过鉴定血源来研究沙蝇的生态相互作用，可以提供有关雌性机会性行为的信息，即吸食各种宿主的血液。因此，本研究旨在确定 CL 流行地区沙蝇与利什曼寄生虫及其血源的生态相互作用。
共采集到 4621 只沙蝇，包括 20 个种，其中最丰富的是 Nyssomyia yuilli yuilli（55.4%）、Psychodopygus ayrozai（14.5%）和 Ps. panamensis（13.4%）。使用 BLASTn 搜索工具对 12S 基因片段的序列进行分析。对 47 只沙蝇的血源进行了成功鉴定，检测到了 7 种脊椎动物，其中人类和犰狳最为常见。从四个雌性沙蝇（Ny. yuilli yuilli 和 Ps. ayrozai）的样本中扩增出了 Leishmania DNA，并通过 RFLP 鉴定出阳性样本中存在 Leishmania（Viannia）panamensis。
在 CL 这一活跃的疫源地中，沙蝇种间、当地哺乳动物区系与利什曼寄生虫之间的相互作用，为两种不同的物种在寄生虫传播中的维持作用提供了证据，这是理解安第斯地区地方性流行地区疾病的生态流行病学和传播动力学的重要信息。然而，还需要进一步评估这些复杂多样地区中媒介和宿主对 Leishmania spp 的传播和维持能力。
