Distribution and Infestation of Gamasid Mite Androlaelaps fahrenholzi (Haemolaelaps glasgowi) on Small Mammals Across Five Provincial Regions of Southwest China.

Being an ectoparasitic species of gamasid mite, Androlaelaps fahrenholzi (Haemolaelaps glasgowi) can serve as the potential vector of haemorrhagic fever with renal syndrome (HFRS) and some other zoonotic diseases. This study reported the distribution and infestation of A. fahrenholzi on rodents and other sympatric small mammals (hosts) across five provincial regions of China for the first time. Infestation indexes were conventionally calculated. At 39 out of 122 survey sites, 1364 A. fahrenholzi mites were identified from 345 rodents and other sympatric small mammal hosts. The hosts of the mites crossed four families, 13 genera and 26 species with low host specificity. The mites were of aggregated distribution on their hosts. Most mites (Cr = 58.36%) came from the mouse Apodemus agrarius with the highest infestation prevalence (PM = 25.51%, p < 0.001). Adult hosts harboured many more mites (Cr = 98.90%) with higher infestation indexes than juvenile ones, with age bias of hosts (p < 0.05). The mite infestation indexes varied in different longitude, latitude and altitude gradients with environmental heterogeneity. Mite infestation indexes were higher in the outdoor habitat and flatland landscape than in the indoor habitat and mountainous landscape (p < 0.05). Female mites were much more than male mites, and adult mites greatly exceeded juvenile mites. The abundant A. fahrenholzi mites occurring on A. agrarius mice would probably increase the potential risk of transmission and focus persistence of related zoonoses in southwest China.