Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy.
Institut Pasteur de Tunis, Tunis, Tunisia.
Parasit Vectors. 2024 Aug 9;17(1):333. doi: 10.1186/s13071-024-06395-2.
Dogs are considered the main domestic animals that may be a reservoir for Leishmania infantum, the agent of zoonotic visceral leishmaniasis (ZVL) in several countries of the world. The dog may host other Leishmania species, but its epidemiological role in the maintenance and spreading of these parasites is not completely elucidated. Zoonotic cutaneous leishmaniasis (ZCL), caused by Leishmania major, affects thousands of people every year and is particularly diffused in many countries of North Africa and Middle East Asia. In ZCL endemic countries, few reports of L. major-positive dogs have been reported, probably because most human cases occur in poor rural areas where the social role of the dog and its medical management is not well considered. The aim of the present study is to better understand the possible involvement of domestic dogs in the epidemiology of ZCL.
Our research focused on a well-established endemic focus of ZCL, in the area of Echrarda, Kairouan Governorate, central Tunisia. A total of 51 dogs with no or mild clinical signs of vector borne diseases were selected in small villages where human cases of ZCL are yearly present. All dogs were sampled for the Leishmania spp. diagnosis, by using the following procedures: blood sample for serology and buffy coat quantitative polymerase chain reaction (qPCR), popliteal fine needle aspiration, and cutaneous biopsy punch for lymph node and skin qPCR.
The results demonstrated a high percentage (21.6%) of dogs positive at least at one or more test; the most sensitive technique was the lymph node qPCR that detected 8/11 positive dogs. Nine, out of the eleven positive dogs, resulted as infected by Leishmania infantum; ITS1-PCR-sequencing allowed Leishmania major identification in the remaining two cases, both from the popliteal lymph node samples, which can suggest a possible visceral spread of a cutaneous Leishmania species in the dog. Interestingly, one of the two L. major-positive dogs was living in the same house where 6-year-old children showed cutaneous lesions referred to as ZCL.
To our knowledge, this is the first report of L. major-positive dogs in Tunisia, the epidemiological role of which remains under investigation.
狗被认为是主要的家养动物，可能是世界上几个国家引起内脏利什曼病（ZVL）的利什曼原虫的宿主。狗可能还携带其他利什曼原虫，但它在维持和传播这些寄生虫方面的流行病学作用尚未完全阐明。由利什曼原虫引起的犬内脏利什曼病（ZVL）每年影响数千人，在北非和中东亚洲的许多国家特别流行。在 ZVL 流行的国家，报告的 L. major 阳性犬病例很少，这可能是因为大多数人类病例发生在贫穷的农村地区，那里对狗的社会作用及其医疗管理没有得到很好的考虑。本研究的目的是更好地了解家养犬在 ZCL 流行病学中的可能作用。
我们的研究集中在突尼斯中部凯鲁万省埃赫拉德地区的一个成熟的 ZCL 流行地区。从小村庄中选择了 51 只没有或只有轻微媒介传播疾病临床症状的狗，这些村庄每年都有人感染 ZCL。所有狗均进行利什曼原虫属的诊断采样，方法如下：血清学和缓冲液层定量聚合酶链反应（qPCR）的血液样本、滑车上细针抽吸术以及皮肤活检冲孔的淋巴结和皮肤 qPCR。
结果显示，至少在一项或多项检测中呈阳性的狗的比例很高（21.6%）；最敏感的技术是淋巴结 qPCR，该技术检测到 8/11 只阳性犬。11 只阳性犬中有 9 只为 L. infantum 感染；ITS1-PCR 测序允许在另外 2 例（均来自滑车上淋巴结样本）中鉴定出 L. major，这可能表明犬中存在一种皮肤利什曼原虫的内脏传播。有趣的是，这 2 只 L. major 阳性犬中的 1 只是与 6 岁儿童同住的，该儿童表现出称为 ZCL 的皮肤病变。
据我们所知，这是突尼斯首次报告 L. major 阳性犬病例，其流行病学作用仍在调查中。
