Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
School of Medicine, Institute of Exact and Natural Sciences, Federal University of Rondonópolis, Rondonópolis, Brazil.
PLoS Negl Trop Dis. 2021 Oct 8;15(10):e0009818. doi: 10.1371/journal.pntd.0009818. eCollection 2021 Oct.
In Brazil, the transmission of Leishmania infantum in urban settings is closely related to infection among dogs, with occasional transmission to humans. Serological screening of dogs for Leishmania spp. infection on requests of their owners (passive case detection) represents a frequent, but little studied, practice within the scope of Brazilian public health. This study identified factors associated with canine visceral leishmaniasis (CVL) diagnosis-seeking behavior of dog owners in Rondonópolis (236,000 inhabitants), a municipality in Central-Western Brazil where VL is endemic. Also, we evaluated the profile of dog owners and their animals screened on free demand.
METHODOLOGY/PRINCIPAL FINDINGS: Using mixed effects negative binomial regression, we modelled the number of dogs screened for Leishmania infection on free demand per neighborhood from 2011 to 2016 as a function of time-dependent predictors (current or recent canine seropositivity and human VL incidence), distance to the screening site, and demographic variables. We assessed potential delays in the effect of time-dependent predictors on the outcome. Among 12,536 dogs screened for Leishmania infection, 64.2% were tested during serosurveys and 35.8% were tested on free demand. Of these, 63.9% were positive. Uptake of screening under free demand was strongly associated with higher levels of canine seropositivity in the neighborhood (current or recent) and decreasing distance to the screening site. A subsample of dog owners (n = 93) who sought CVL screening between 2016 and 2017 were interviewed in more detail. Owners with better socioeconomic status and dogs with apparent CVL clinical manifestations prevailed among them.
CONCLUSIONS/SIGNIFICANCE: To support timely CVL management, passive case detection along with awareness activities aimed at dog owners should be encouraged in endemic areas. Screening sites should be prioritized in accessible zones, as well as in socio-economically disadvantage areas. In parallel, CVL active case detection should be continued as a surveillance tool to guide control actions.
在巴西，城市环境中莱姆病的传播与犬类感染密切相关，偶尔也会传染给人类。根据主人的要求对犬类进行莱姆病感染血清学筛查（被动病例检测）是巴西公共卫生领域中常见但研究较少的做法。本研究旨在确定与罗ndonópolis（人口 236000）犬内脏利什曼病（CVL）诊断寻求行为相关的因素，该城市位于巴西中西部，是利什曼病流行地区。此外，我们还评估了有偿需求筛查的犬主及其动物的特征。
方法/主要发现：我们使用混合效应负二项回归模型，根据时间相关预测因素（当前或近期犬血清阳性和人类利什曼病发病率）、与筛查点的距离以及人口统计学变量，来模拟 2011 年至 2016 年每个街区有偿需求筛查的犬数量。我们评估了时间相关预测因素对结果的潜在滞后效应。在筛查的 12536 只犬中，64.2%是在血清学调查中检测的，35.8%是在有偿需求下检测的。其中，63.9%呈阳性。在有偿需求下，筛查的参与度与社区（当前或近期）中更高水平的犬血清阳性率和与筛查点距离的缩短呈强相关。2016 年至 2017 年间寻求 CVL 筛查的犬主人（n=93）的一个子样本接受了更详细的访谈。他们中，社会经济地位较好的犬主和具有明显 CVL 临床症状的犬较多。
结论/意义：为了支持及时的 CVL 管理，应在流行地区鼓励被动病例检测和针对犬主的宣传活动。应优先考虑在可及区域以及社会经济劣势区域设立筛查点。同时，应继续进行 CVL 主动病例检测，作为监测工具，以指导控制行动。
