Programa de Pós-Graduação em Ciências Farmacêuticas, Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Minas Gerais, Brazil.
Laboratório de Imunopatologia, Programa de Pós-Graduação em Ciências Biológicas, Núcleo de Pesquisa em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.
PLoS One. 2018 Dec 10;13(12):e0208613. doi: 10.1371/journal.pone.0208613. eCollection 2018.
To reduce morbidity and mortality caused by visceral leishmaniasis (VL), the Brazilian Visceral Leishmaniasis Control and Surveillance Program promotes the diagnosis and treatment of cases, vector control, euthanasia of seropositive dogs, and health education. Nevertheless, the effectiveness of these measures is questionable as they lead to little reduction in the transmission of the disease. Thus, the effectiveness of strategies such as insecticide-impregnated collars, spot-on insecticides, and immunization of dogs should be assessed. Herein, we evaluated the effectiveness of deltamethrin-impregnated collars on reducing the incidence of Leishmania infantum infection in dogs living in an endemic area of VL. An intervention study was conducted and a total 5,850 dogs were analyzed in baseline. Of these 3,742 seronegative dogs were divided into two groups: collared and uncollared (control). Dogs were followed for 12 months and three interventions were performed. The Cox regression model was used to evaluate the effectiveness of the collar. All analyzes were performed by Intention-to-treat and per-protocol. By intention-to-treat, the incidence rates of L. infantum infection were 7.5 and 7.9 in the collar group, and 6.5 and 13.2 per 1,000 dogs-months in the control group after 6 and 12 months, respectively. In the per-protocol analysis, the incidence rates in the control group were similar to those observed in the intention-to-treat analysis. In the collar group, the incidence rate was 5.1/1,000 dogs-months after 6 and 12 months. The effectiveness by intention-to-treat after adjustment by the multivariate Cox model was 48%. In the analysis per-protocol, the effectiveness increased to 63%. Although collar use was effective when it was evaluated by intention-to-treat, higher effectiveness was found in the per-protocol analysis after one year of follow-up. The data emphasize the importance of the uninterrupted use of deltamethrin-impregnated collars to increase protection against canine VL.
为降低内脏利什曼病（VL）所致发病率和死亡率，巴西内脏利什曼病控制和监测计划推动了病例诊断和治疗、病媒控制、对血清阳性犬实施安乐死和开展卫生教育。然而，这些措施的效果值得质疑，因为它们对疾病传播的减少作用不大。因此，应评估驱虫项圈、驱虫滴剂和犬免疫等策略的效果。在此，我们评估了在 VL 流行地区，使用含氯菊酯驱虫项圈降低感染利什曼原虫犬发病率的效果。进行了一项干预研究，对基线时的 5850 只犬进行了分析。其中 3742 只血清阴性犬分为两组：佩戴项圈组和未佩戴项圈组（对照组）。对犬进行了 12 个月的随访，并进行了 3 次干预。采用 Cox 回归模型评估项圈的效果。所有分析均通过意向治疗和方案分析进行。意向治疗分析显示，佩戴项圈组 6 个月和 12 个月时的利什曼原虫感染发病率分别为 7.5 和 7.9/1000 犬-月，对照组分别为 6.5 和 13.2/1000 犬-月。方案分析中，对照组的发病率与意向治疗分析观察到的结果相似。佩戴项圈组 6 个月和 12 个月时的发病率分别为 5.1/1000 犬-月。多变量 Cox 模型调整后的意向治疗分析的效果为 48%。方案分析中，一年随访后的效果增加至 63%。尽管意向治疗分析显示使用项圈有效，但在一年随访后的方案分析中发现效果更高。这些数据强调了连续使用含氯菊酯驱虫项圈对增加犬内脏利什曼病防护的重要性。
