Human Spotted Fever Group Infecting Yaks () in the Qinghai-Tibetan Plateau Area.

The Qinghai-Tibetan Plateau Area (QTPA) is a plateau with the highest average altitude, located in Northwestern China. There is a risk for interspecies disease transmission, such as spotted fever rickettsioses. However, information on the molecular characteristics of the spotted fever group (SFG) spp. in the area is limited. This study performed screenings, and detected the DNA of human pathogen, SFG spp., with 11.3% (25/222) infection rates in yaks ( ). BLASTn analysis revealed that the sequences obtained shared 94.3-100% identity with isolates of spp. from ticks in China. One sequence (MN536161) had 100% nucleotide identity to two isolates from Chinese , and one isolate from Qinghai . Meanwhile, another sequence (MN536157) shared 99.1-99.5% identity to one isolate from spp. in China. Furthermore, the phylogenetic analysis of SFG spp. gene revealed that these two sequences obtained from yaks in the present study grouped with the and clades with isolates identified from spp. and . Our findings showed the first evidence of human pathogen DNA, SFG spp., from animals, in the QTPA.