Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Avenida San Miguel 3605, Talca, 3480112, Chile.
Laboratorio de Microbiología y Parasitología, Departamento de Ciencias Preclínicas, Facultad de Medicina, Universidad Católica del Maule, Avenida San Miguel 3605, Talca, 3480112, Chile.
Acta Trop. 2022 Feb;226:106230. doi: 10.1016/j.actatropica.2021.106230. Epub 2021 Nov 19.
Dirofilaria repens is a nematode affecting domestic and wild canids, transmitted by several species of mosquitoes of different genera. It usually causes a non-pathogenic subcutaneous infection in dogs and is the principal agent of human dirofilariasis in the Old World. The geographic distribution of D. repens is changing rapidly, and several factors contribute to the spread of the infection to non-endemic areas. A mathematical model for transmission of Dirofilaria spp. was built, using a system of ordinary differential equations that consider the interactions between reservoirs, vectors, and humans. The transmission simulations of D. repens were carried out considering a projection in time, with intervals of 15 and 100 years. For the dynamics of the vector, seasonal variations were presented as series with quarter periodicity during the year. The results of the simulations highlight the peak of contagions in the reservoir and in humans, a product of the action of the vector when it remains active throughout the year. A 300% infection increase in the reservoir was observed during the first decade and remains present in the population with a representative number of cases. When the vector maintains its density and infectivity during the year, the incidence of the infection in humans increases. Accumulated cases amount to 45 per 100,000 inhabitants, which corresponds to a cumulative incidence of 0.05%, in 85 years. This indicates that early prevention of infection in canids would significantly reduce the disease, also reducing the number of accumulated cases of human dirofilariasis by D. repens. The interaction between the simulations generated by the model highlights the sensitivity of the epidemiological curve to the periodicity of seasonality, reaffirming the hypothesis of the probability of movement of the zoonotic disease to non-endemic areas, due to climate change.
犬心丝虫是一种影响家犬和野生犬科动物的线虫，由不同属的几种蚊子传播。它通常在犬中引起非致病性的皮下感染，是旧世界人类犬心丝虫病的主要病原体。犬心丝虫的地理分布正在迅速变化，有几个因素导致感染传播到非流行地区。建立了一种犬心丝虫属传播的数学模型，使用一个常微分方程组系统，考虑了储主、媒介和人类之间的相互作用。考虑到时间的投影，对犬心丝虫的传播进行了模拟，间隔为 15 年和 100 年。对于媒介的动态，季节性变化表现为一年中具有四分之一周期性的系列。模拟结果突出了储主和人类中传染病的高峰，这是媒介全年保持活跃时作用的产物。在第一个十年中，储主的感染率增加了 300%，并且在具有代表性病例数的人群中仍然存在。当媒介在一年中保持其密度和感染力时，人类感染的发病率会增加。累计病例数达到每 10 万人 45 例，这相当于 85 年内累积发病率为 0.05%。这表明，早期预防犬类感染将显著减少该疾病，还将通过犬心丝虫减少人类犬心丝虫病的累计病例数。该模型产生的模拟之间的相互作用突出了季节性周期性对流行病学曲线的敏感性，再次证实了由于气候变化，人畜共患病向非流行地区传播的可能性假设。
