Zoghlami Z, Chouihi E, Barhoumi W, Dachraoui K, Massoudi N, Helel K Ben, Habboul Z, Hadhri M H, Limam S, Mhadhbi M, Gharbi M, Zhioua E
Laboratory of Vector Ecology, Pasteur Institute of Tunis, 13 Place Pasteur BP 74, 1002 Tunis, Tunisia.
Pediatric Department, University Hospital of Kairouan, Tunisia.
Acta Trop. 2014 Nov;139:32-8. doi: 10.1016/j.actatropica.2014.06.012. Epub 2014 Jul 5.
Canine visceral leishmaniasis (CVL) is endemic in the Mediterranean basin. In Tunisia, CVL is spatially associated with human visceral leishmaniasis (HVL) affecting mostly children younger than 5 years old. In this study, seroprevalence of Leishmania infantum infection in dogs was assessed in highly endemic districts of the governorate of Kairouan where more than 50% of HVL cases in Tunisia were reported. An entomological investigation was also carried out in two endemic districts (Bouhajla and Haffouz) to assess sand fly fauna and infection status of sand flies with Leishmania. A total of 191 serum samples were collected from healthy dogs and tested for anti-L. infantum antibodies by indirect immunofluorescence antibody test (IFAT). Overall seroprevalence for L. infantum was 26.7% being highest among dogs in the district of Bouhajla (52.7%) and the lowest in the district of Chbika (5.2%). In dogs, seroprevalence did not differ significantly based on gender or age, with dogs younger than 1 year showing a higher seroprevalence compared to older dogs. These findings suggest strong force of infection in naïve animals in holoendemic regions leading to emerging high incidence of HVL. Concomitant to the high CVL prevalence observed in the Bouhajla district, a significantly high cumulative HVL incidence also was observed in this district. Phlebotomus perniciosus and Phlebotomus longicuspis were the most abundant sand fly species in Bouhajla and Haffouz districts. The rate of Leishmania-DNA infection in sand flies was 9.4%. This finding points to spatial correlation between the occurrence of disease in humans, a high rate of infection in dogs and a high abundance of P. pernicious and P. longicuspis. Thus, CVL is the main risk factor for transmission to humans and subsequently, it is an important parameter for controlling transmission to humans.
犬内脏利什曼病（CVL）在地中海盆地为地方病。在突尼斯，CVL在空间上与主要影响5岁以下儿童的人类内脏利什曼病（HVL）相关。在本研究中，在凯鲁万省高度流行地区评估了犬利什曼原虫婴儿亚种感染的血清阳性率，该地区报告了突尼斯50%以上的HVL病例。还在两个流行地区（布哈伊拉和哈富兹）进行了昆虫学调查，以评估白蛉种类和白蛉感染利什曼原虫的状况。从健康犬采集了191份血清样本，并通过间接免疫荧光抗体试验（IFAT）检测抗婴儿利什曼原虫抗体。婴儿利什曼原虫的总体血清阳性率为26.7%，在布哈伊拉地区的犬中最高（52.7%），在奇比卡地区最低（5.2%）。在犬中，血清阳性率在性别或年龄方面无显著差异，1岁以下的犬比年长犬的血清阳性率更高。这些发现表明，在全地方流行区，初免动物的感染压力很大，导致HVL发病率不断上升。与在布哈伊拉地区观察到的高CVL患病率同时，该地区也观察到显著高的累积HVL发病率。在布哈伊拉和哈富兹地区，有害白蛉和长喙白蛉是最常见的白蛉种类。白蛉中利什曼原虫DNA感染率为9.4%。这一发现表明人类疾病的发生、犬的高感染率以及有害白蛉和长喙白蛉的高丰度之间存在空间相关性。因此，CVL是传播给人类的主要危险因素，随后，它是控制向人类传播的重要参数。
