Department of Medical Laboratory Sciences, College of Medicine and Health Sciences, Wolkite University, Wolkite, Ethiopia.
Department of Medical Laboratory Sciences and Pathology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia.
PLoS One. 2018 May 24;13(5):e0197430. doi: 10.1371/journal.pone.0197430. eCollection 2018.
Visceral leishmaniasis [VL] is a debilitating parasitic disease which invariably kills untreated patients. The disease is caused by Leishmania (L.) donovani or L. infantum, and transmitted by the bite of female phlebotomine sandflies. VL often remains subclinical but can become symptomatic with an acute/subacute or chronic course. Globally, the Eastern Africa region is one of the main VL endemic areas. The disease is prevalent in numerous foci within Eritrea, Ethiopia, Kenya, Somalia, Sudan South Sudan, and Uganda. In Ethiopia, the Lower Omo plain is one of the many VL endemic regions.
The objective of this study was to determine the prevalence of asymptomatic visceral leishmaniasisin Hamar and Banna-Tsamai districts of the South Omo plains where VL is becoming an emerging health problem of neglected communities.
A community based cross-sectional survey was conducted in 2013 between 25th of July and 14th of August. A total of 1682 individuals living in 404 households were included in the study. Socio-demographic and clinical data were collected from each of the participants and venous blood was also collected for the detection of antibodies to visceral leishmaniasis using Direct Agglutination Test. Leishmanin Skin Test was performed to detect the exposure to the parasite.
The surveys included 14 villages located in areas where VL had been reported. In a study population of 1682 individuals, the overall positive leishmanian skin test and sero-prevalence rates respectively were 8.6% and 1.8%. A statistically significant variation in the rate of positive LST response was observed in different study sites and age groups. Positive LST response showed an increasing trend with age. The sero-prevalence rate also showed a statistically significant variation among different study sites. Higher rates of sero-prevalence were observed in children and adolescents. The LST and sero-prevalence rates in Hamar District exceeded significantly that of Banna-Tsamai District (10.7% versus 5.8% for LST; and 2.6% versus 0.7% for sero-prevalence).
The prevalence of asymptomatic VL infection in Hamar and Banna-Tsamai districts during the study period in 2013 was low compared to rates previously reported in other endemic areas of Ethiopia. This could be due to the fact that the disease is emerging in Hamar and Banna-Tsamai districts. Based on records of a nearby Hospital, increasing numbers of active VL cases have been reported in these districts through the years 2006-2012, especially in Hamar District. Both districts are important destinations of tourism, and thus the importance of surveillance should be emphasized. Detailed epidemiological and entomological studies are recommended.
内脏利什曼病（VL）是一种使人虚弱的寄生虫病，未经治疗的患者无一例外地会死亡。这种疾病是由利什曼原虫（L.）引起的。 Donovanii 或 L. infantum，并通过雌性嗜人锥蝇的叮咬传播。VL 通常处于亚临床状态，但可能会出现急性/亚急性或慢性病程。在全球范围内，东非地区是内脏利什曼病的主要流行地区之一。该疾病在厄立特里亚、埃塞俄比亚、肯尼亚、索马里、苏丹、南苏丹和乌干达的许多地方都很普遍。在埃塞俄比亚，下奥莫平原是内脏利什曼病的众多流行地区之一。
本研究旨在确定 Hamar 和 Banna-Tsamai 区无症状内脏利什曼病的流行率，在这些地区，内脏利什曼病正成为被忽视社区的一个新出现的健康问题。
2013 年 7 月 25 日至 8 月 14 日期间进行了一项基于社区的横断面调查。共有 1682 名居住在 404 户家庭中的个人参加了这项研究。从每位参与者那里收集了社会人口统计学和临床数据，并采集了静脉血，用于使用直接凝集试验检测内脏利什曼病的抗体。进行利什曼菌素皮肤试验以检测对寄生虫的暴露。
调查包括在报告有内脏利什曼病的地区的 14 个村庄。在 1682 名研究人群中，总体阳性利什曼皮肤试验和血清阳性率分别为 8.6%和 1.8%。在不同的研究地点和年龄组中，阳性 LST 反应率存在统计学显著差异。阳性 LST 反应率随年龄增长呈上升趋势。血清阳性率在不同的研究地点也存在统计学显著差异。在儿童和青少年中观察到更高的血清阳性率。Hamar 区的 LST 和血清阳性率显著高于 Banna-Tsamai 区（LST 分别为 10.7%对 5.8%；血清阳性率分别为 2.6%对 0.7%）。
与之前在埃塞俄比亚其他流行地区报告的比率相比，2013 年研究期间在 Hamar 和 Banna-Tsamai 区无症状 VL 感染的流行率较低。这可能是因为该疾病正在 Hamar 和 Banna-Tsamai 区出现。根据附近一家医院的记录，自 2006 年至 2012 年，这些地区报告的活动性 VL 病例数量不断增加，特别是在 Hamar 区。这两个区都是重要的旅游目的地，因此应强调监测的重要性。建议进行详细的流行病学和昆虫学研究。
