Variation in Small Mammal Species Composition and the Occurrence of Parasitic Mites in Two Landscapes in a Scrub Typhus Endemic Region of Western Yunnan Province, China

Western Yunnan Province is a scrub typhus endemic region, providing optimal environments for small mammal hosts and mite vectors. This study explored the association between mite occurrence on small mammals and landscape and host characteristics in this region. Two landscapes, farmland and forest edge, in four locations in Tengchong City were sampled for capturing small mammals and collecting mites. Associations among host, vector, and landscape were analyzed using hurdle negative binomial mixed models. Among 279 small mammals captured, ninety-five individuals were infested with a total of 8308 mites. Infestation prevalence was higher in farmland than in the forest edge. Mean mite intensity was 87.5/infested mammal. The highest mite intensity was seen in <i>Neotetracus sinensis</i>. <i>Rattus tanezumi</i>, <i>Suncus murinus</i>, <i>Rattus rattus</i>, and <i>Mus pahari</i> were dominant species. Differences in infestation prevalence and mite intensity were inconsistent across species and landscape. In farmland, <i>Rattus tanezumi</i> and <i>Rattus rattus</i> had a significantly higher infestation prevalence than non-dominant species. Adult mammals had significantly higher infestation prevalence independent of species and landscape. Larger body size, longer tail, hind leg, and ear were each related to significantly higher infestation prevalence, but the effects were reduced by half after adjusting for species and landscape. Mite intensity was not related to hosts. In conclusion, infestation prevalence and mite intensity varied across species. Infestation prevalence was higher in farmland than in forest edge and was positively related to adult mammals and larger body dimensions.