Sevá Anaiá da Paixão, Martcheva Maia, Tuncer Necibe, Fontana Isabella, Carrillo Eugenia, Moreno Javier, Keesling James
Department of Mathematics of University of Florida, Gainesville, Florida, United States of America.
Department of Mathematical Sciences of Florida Atlantic University, Boca Raton, Florida, United States of America.
PLoS One. 2017 Oct 13;12(10):e0186372. doi: 10.1371/journal.pone.0186372. eCollection 2017.
Leishmaniasis is a vector-borne disease of worldwide distribution, currently present in 98 countries. Since late 2010, an unusual increase of human visceral and cutaneous leishmaniasis cases has been observed in the south-western Madrid region, totaling more than 600 cases until 2015. Some hosts, such as human, domestic dog and cat, rabbit (Oryctolagus cuniculus), and hare (Lepus granatensis), were found infected by the parasite of this disease in the area. Hares were described as the most important reservoir due to their higher prevalence, capacity to infect the vector, and presence of the same strains as in humans. Various measures were adopted to prevent and control the disease, and since 2013 there was a slight decline in the human sickness. We used a mathematical model to evaluate the efficacy of each measure in reducing the number of infected hosts. We identified in the present model that culling both hares and rabbits, without immediate reposition of the animals, was the best measure adopted, decreasing the proportion of all infected hosts. Particularly, culling hares was more efficacious than culling rabbits to reduce the proportion of infected individuals of all hosts. Likewise, lowering vector contact with hares highly influenced the reduction of the proportion of infected hosts. The reduction of the vector density per host in the park decreased the leishmaniasis incidence of hosts in the park and the urban areas. On the other hand, the reduction of the vector density per host of the urban area (humans, dogs and cats) decreased only their affected population, albeit at a higher proportion. The use of insecticide-impregnated collar and vaccination in dogs affected only the infected dogs' population. The parameters related to the vector contact with dog, cat or human do not present a high impact on the other hosts infected by Leishmania. In conclusion, the efficacy of each control strategy was determined, in order to direct future actions in this and in other similar outbreaks. The present mathematical model was able to reproduce the leishmaniasis dynamics in the Madrid outbreak, providing theoretical support based on successful experiences, such as the reduction of human cases in Southwest Madrid, Spain.
利什曼病是一种由媒介传播的疾病，在全球范围内均有分布，目前在98个国家存在。自2010年末以来，马德里西南部地区出现了人类内脏利什曼病和皮肤利什曼病病例异常增加的情况，到2015年总数超过600例。在该地区发现一些宿主，如人类、家犬和家猫、兔子（穴兔）以及野兔（格兰纳野兔）感染了这种疾病的寄生虫。野兔被描述为最重要的储存宿主，因为它们的患病率更高、感染媒介的能力以及与人类存在相同的菌株。采取了各种措施来预防和控制该疾病，自2013年以来人类患病情况略有下降。我们使用一个数学模型来评估每种措施在减少感染宿主数量方面的效果。我们在当前模型中确定，捕杀野兔和兔子且不立即重新安置这些动物是所采取的最佳措施，可降低所有感染宿主的比例。特别是，捕杀野兔比捕杀兔子在降低所有宿主感染个体比例方面更有效。同样，减少媒介与野兔的接触对降低感染宿主比例有很大影响。公园内每个宿主的媒介密度降低，可降低公园内及城市地区宿主的利什曼病发病率。另一方面，城市地区（人类、犬类和猫类）每个宿主的媒介密度降低，仅能降低其受影响的种群数量，尽管比例更高。在犬类中使用杀虫剂浸渍项圈和疫苗接种仅影响感染犬类的种群数量。与媒介接触犬、猫或人类相关的参数对其他感染利什曼原虫的宿主没有很大影响。总之，确定了每种控制策略的效果，以便指导在此次及其他类似疫情中的未来行动。当前的数学模型能够重现马德里疫情中利什曼病的动态，基于成功经验（如西班牙马德里西南部人类病例的减少）提供理论支持。
