Lemma Wossenseged, Bizuneh Asrat, Tekie Habte, Belay Habtamu, Wondimu Hirut, Kassahun Aysheshm, Shiferaw Welelta, Balkew Meshesha, Abassi Ibrahim, Baneth Gad, Hailu Asrat
Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
Department of Microbiology, Immunology and Parasitology, School of Medicine, Addis Ababa University, Addis Ababa, Ethiopia.
Asian Pac J Trop Med. 2017 Apr;10(4):418-422. doi: 10.1016/j.apjtm.2017.03.018. Epub 2017 Apr 6.
To investigate the zoonotic visceral leishmaniasis (ZVL) by identification of the most probable reservoir hosts using parasite isolation and analysis of a possible transmission dynamics of the disease in extra-domestic agricultural fields and rural villages.
Rodents were collected from selected study sites in kala-azar endemic areas based on information for localities of kala-azar cases for screening of Leishmania infections using parasitological, serological and polymerase chain reaction (PCR) from March, 2013 to January, 2014. Ketamine (Clorketam Veterinary) was used to anaesthesize the rodents according the prescribed dosage (average 2 mg/kg for intra-venous route). The blood obtained using sterile needle was dropped into sterile filter paper and allowed to air dry before sealing in plastic bags. The tissues from liver, spleen and skin were macerated in Locke's solution before transferring them into NNN medium. Blood and touch smears of liver, spleen, skin and bone marrow were prepared for fixing using methanol and staining by Giemsa stain for microscopy. These tissues were also used for DNA extractions and PCR amplification of Leishmania infection.
A total of 335 rodents (13 species) were analyzed by sampling internal organs. The infection rate by PCR was 11.1% (6/54) for Arvicanthis nilothicus compared to 17.6% (3/17) and 12.5% (2/16) for Acomys cahirinus and Tarera (G) robustus respectively. Almost all the infections were found from bone marrow samples (8/48 or 16.7%) compared with 1/91 (1.1%) liver, 2/87 (2.2%) spleen and 0/87 (0%) skin. In all study sites with past human VL cases, rodents and proved vectors shared similar habitats.
Leishmania donovani might circulate among different species of rodents in kala-azar endemic lowlands and valleys of Ethiopia by Phlebotomus orientalis and Phlebotomus martini. Detailed studies to substantiate the preliminary data on the possible role of these rodents are urgently needed.
通过寄生虫分离以及对该病在家庭外农田和乡村可能的传播动态进行分析，确定最有可能的储存宿主，从而调查人兽共患内脏利什曼病（ZVL）。
根据黑热病病例所在地区的信息，于2013年3月至2014年1月从黑热病流行地区的选定研究地点收集啮齿动物，采用寄生虫学、血清学和聚合酶链反应（PCR）方法筛查利什曼原虫感染。按照规定剂量（静脉注射平均2mg/kg）使用氯胺酮（Clorketam Veterinary）对啮齿动物进行麻醉。使用无菌针头采集的血液滴入无菌滤纸上，晾干后装入塑料袋密封。肝脏、脾脏和皮肤组织在洛克氏溶液中研磨后转移至NNN培养基。制备肝脏、脾脏、皮肤和骨髓的血液涂片及触片，用甲醇固定，吉姆萨染色后进行显微镜检查。这些组织还用于DNA提取和利什曼原虫感染的PCR扩增。
通过对335只（13种）啮齿动物的内脏进行采样分析，尼罗多乳鼠的PCR感染率为11.1%（6/54），而埃及刺鼠和粗壮肥鼠的感染率分别为17.6%（3/17）和12.5%（2/16）。几乎所有感染均在骨髓样本中发现（8/48或16.7%），相比之下，肝脏样本为1/91（1.1%），脾脏样本为2/87（2.2%），皮肤样本为0/87（0%）。在所有曾有人类黑热病病例的研究地点，啮齿动物和已证实的传播媒介共享相似的栖息地。
杜氏利什曼原虫可能通过东方白蛉和马丁氏白蛉在埃塞俄比亚黑热病流行的低地和山谷中的不同啮齿动物物种之间传播。迫切需要进行详细研究以证实这些啮齿动物可能作用的初步数据。
