Research Unit of Biology and Applied Ecology, University of Dschang, Dschang, Cameroon.
Laboratory of the Leishmaniasis Research Project, Mokolo District Hospital, Mokolo, Cameroon.
Trop Med Int Health. 2018 Sep;23(9):1014-1021. doi: 10.1111/tmi.13123. Epub 2018 Jul 30.
A sound knowledge of the vector-host-parasite transmission dynamics is a prerequisite for adequate control measures of vector-borne diseases. To achieve this, an entomological investigation was conducted in the cutaneous leishmaniasis (CL) endemic focus of Mokolo District, northern Cameroon to identify the insect vector(s) of the disease.
Phlebotomine sand flies were collected in and around Mokolo using New Standard CDC Miniature Light Traps. Individual sand flies were used for morphological species identification, and the remainder of the body for DNA analysis. Sand flies were demonstrated to harbour Leishmania spp. parasites using ITS1 PCR. Mitochondrial vertebrate-specific Cytochrome b -PCR was used to identify blood meals ingested by female sand flies. PCR amplicons were sequenced for Leishmania and blood sources discrimination.
This study revealed the presence of Leishmania donovani complex DNA (n = 1) in Phlebotomus duboscqi and of lizard-borne Leishmania tarentolae-like DNA (n = 3) in Sergentomyia spp. in 79 sand fly specimens from Mokolo district.
The causative agent of CL could not be detected in potential vectors. Instead, we found evidence for visceral leishmaniasis (VL) parasites in Phlebotomus duboscqi as well as enzootic reptile parasites in the Mokolo area. We recommend that an epidemiological survey be carried out in the area to evaluate the prevalence and eventually describe the clinical manifestations of VL in the human population. Political instability in neighbouring countries and the resulting refugee migration are likely explanations for the emergence of VL in Mokolo.
充分了解病媒传播动力学是对媒介传播疾病进行有效控制的前提。为此，在喀麦隆北部莫科洛地区的皮肤利什曼病（CL）流行区进行了昆虫学调查，以确定该病的病媒。
使用新型标准 CDC 迷你诱捕器在莫科洛及其周围收集沙蝇。对单个沙蝇进行形态种鉴定，其余部分进行 DNA 分析。使用 ITS1 PCR 检测沙蝇是否携带利什曼原虫属寄生虫。使用线粒体脊椎动物特异性细胞色素 b-PCR 鉴定雌性沙蝇摄入的血液来源。对 PCR 扩增子进行测序，以区分利什曼原虫和血液来源。
本研究在来自莫科洛地区的 79 只沙蝇标本中发现了杜氏利什曼原虫复合体 DNA（n = 1）存在于珀氏疟蚊和蜥蜴传播的利什曼原虫 tarentolae 样 DNA（n = 3）中。
在潜在媒介中未检测到 CL 的病原体。相反，我们在珀氏疟蚊中发现了内脏利什曼病（VL）寄生虫的证据，在莫科洛地区还发现了地方性的爬行动物寄生虫。我们建议在该地区进行流行病学调查，以评估 VL 在人群中的流行率，并最终描述其临床表现。邻国的政治不稳定以及由此导致的难民迁移可能是 VL 在莫科洛出现的原因。
