Institute of Tropical Medicine, Antwerp, Belgium.
B P Koirala Institute of Health Sciences, Dharan, Nepal.
Lancet Glob Health. 2020 Feb;8(2):e237-e243. doi: 10.1016/S2214-109X(19)30536-4.
Nepal launched a visceral leishmaniasis (also known as kala-azar) elimination initiative in 2005. We primarily aimed to assess whether transmission of Leishmania donovani had decreased since the launch of the initiative. We also assessed the validity of the direct agglutination test (DAT) as a marker of infection, in view of future surveillance systems.
We did a repeat survey in a population aged 2 years and older for whom baseline serological data were available from 2006. Data were from three districts in the eastern region of Nepal. The primary outcome of interest was prevalent infection with L donovani as measured with DAT (cutoff value ≥1:3200). We compared age group-specific and cluster-specific seroprevalences in 2016 with those in 2006, using χ tests, with a specific focus on the comparison of seroprevalences in children born between 1996 and 2005, and those born between 2006 and 2015. To estimate the overall adjusted risk ratio for being seropositive in 2016 compared with 2006, we fitted a Poisson model controlling for age, sex, and cluster.
Between Oct 17, 2016, and Dec 26, 2016, we assessed 6609 individuals. DAT prevalence in children younger than 10 years was 4·1% (95% CI 3·2-5·4) in 2006 versus 0·5% (0·1-1·7) in 2016 (p<0·0001). Seroprevalence was lower in 2016 than in 2006 in all age groups and in all repeated clusters. The overall adjusted risk ratio of being seropositive was 0·44 (95% CI 0·37-0·52) for 2016 compared with 2006, and 0·04 (0·01-0·16) in children younger than 10 years.
Our findings show that transmission of L donovani in Nepal has decreased significantly between 2006 and 2016, coinciding with the elimination programme. DAT seems useful for monitoring of L donovani transmission.
The Directorate-General for Development Cooperation of Belgium.
尼泊尔于 2005 年启动了内脏利什曼病（也称为黑热病）消除倡议。我们的主要目的是评估自倡议启动以来，是否已经降低了利什曼原虫的传播。鉴于未来的监测系统，我们还评估了直接凝集试验（DAT）作为感染标志物的有效性。
我们对 2006 年有基线血清学数据的 2 岁及以上人群进行了重复调查。数据来自尼泊尔东部的三个地区。主要结局是通过 DAT（临界值≥1:3200）测量的利什曼原虫的现患感染。我们使用卡方检验比较了 2016 年和 2006 年的年龄组特异性和聚类特异性血清流行率，并特别关注了 1996 年至 2005 年和 2006 年至 2015 年出生的儿童之间的血清流行率比较。为了估计与 2006 年相比，2016 年血清阳性的总体调整风险比，我们通过控制年龄、性别和聚类，拟合了泊松模型。
2016 年 10 月 17 日至 12 月 26 日，我们评估了 6609 人。2006 年，10 岁以下儿童的 DAT 流行率为 4.1%（95%CI 3.2-5.4），而 2016 年为 0.5%（0.1-1.7）（p<0.0001）。在所有年龄组和所有重复聚类中，2016 年的血清流行率均低于 2006 年。与 2006 年相比，2016 年的总体调整风险比为 0.44（95%CI 0.37-0.52），而 10 岁以下儿童的风险比为 0.04（0.01-0.16）。
我们的研究结果表明，2006 年至 2016 年间，尼泊尔利什曼原虫的传播明显减少，与消除规划相符。DAT 似乎可用于监测利什曼原虫的传播。
比利时发展合作总司。
