Rodents play a significant role as reservoirs of zoonotic diseases. Nevertheless, in general their ectoparasite assemblage and host-ectoparasite associations are poorly known. This study intended to provide new insights into the relationships between ectoparasites and rodents in northeastern Iran. Rodents were captured using live traps during the years 2016–2020, and their ectoparasites were collected. Parasitological indices such as infestation rate, prevalence and mean intensity of infestation were analyzed. A total of 284 rodents, belonging to 17 species, were trapped and found to be infested by 178 ectoparasites from five orders Siphonaptera, Phthiraptera, Ixodida, Mesostigmata and Trombidiformes. The overall infestation rate was 50.3%. The flea Nosopsyllus fasciatus and the louse Polyplax asiatica dominated among all fleas and lice, respectively. Haemaphysalis punctata and Haemolaelaps sp. were recorded as the most abundant tick and mite, respectively. Nosopsyllus fasciatus exhibited low and Polyplax asiatica moderate host specificity. Approximately 64.2% of ectoparasites shared more than one host, and others were singletons. Seasonal fluctuations were found in the occurrence of ectoparasite; fleas and lice were more abundant in spring and winter, respectively. Ticks demonstrated high abundance in spring and summer and mites were more common in autumn. The overall prevalence of ectoparasite on male rodents was greater than that on females (56.4% vs. 44.4%), while similar mean intensities were detected for both sexes. This study extends the knowledge on the distribution, seasonality and host choice of four main groups of ectoparasites in association with rodents. Further studies are needed to provide deep insight into how relationships and interactions between ectoparasite and rodents are formed, and how they can be applied in epidemiology.

啮齿动物作为人畜共患疾病的储库发挥着重要作用。然而，总的来说，它们的体外寄生虫组合和宿主-体外寄生虫的联系鲜为人知。这项研究旨在为伊朗东北部外寄生虫与啮齿动物之间的关系提供新的见解。在2016–2020年期间，使用活捕虫器捕获了啮齿动物，并收集了它们的体外寄生虫。分析了寄生虫学指标，例如感染率，患病率和平均感染强度。总共捕获了284种啮齿动物，它们属于17个物种，并被来自五个阶Siphonaptera，Phthiraptera，Ixodida，Mesostigmata和Trombidiformes的178种外生寄生虫感染。整体感染率为50.3％。跳蚤Nosopsyllus fasciatus和虱子在所有跳蚤和虱子中，Polyplax asiatica占主导地位。点状血蜱和Haemolaelaps SP。被记录为最丰富的tick和螨。筋膜Nosopsyllus fasciatus表现出较低的体积和Polyplax asiatica中度的宿主特异性。约64.2％的体外寄生虫共享一个以上的宿主，其他为单例。在外寄生虫的发生中发现季节性波动；跳蚤和虱子分别在春季和冬季更为丰富。spring虫在春季和夏季表现出很高的丰度，而在秋季则更为常见。雄性啮齿动物的总寄生虫患病率高于雌性啮齿动物（56.4％对44.4％），而男女性别平均检出强度相似。这项研究扩展了与啮齿类动物有关的四个主要外寄生虫的分布，季节性和寄主选择的知识。需要进一步的研究来深入了解外寄生物与啮齿动物之间的关系和相互作用是如何形成的，以及它们如何在流行病学中得到应用。