Moleculare detection of Bartonella in ixodid ticks and plateau pika (Ochotona curzoniae) in Shiqu county, China

Abstract Background Bartonella bacteria have been associated with an increasingly wide range of human and animal diseases and were also recognized to be globally dispersed as emergent pathogens. Ticks and small rodents are known vectors of human and animal bartonellosis and play important roles in maintenance and circulation of bartonellae in nature. In China, Shiqu county is located on the eastern Qinghai-Tibetan plateau and about 26 thousands square kilometers with an average altitude of above 4,200 meters and vast area of pastureland. In present study, the occurrence of Bartonella spp. in ticks and plateau pika was firstly investigated in Shiqu county.Results A total of 818 ticks ( Dermacentor everestianus , 79.0%, 646/818; Haemphysalis qinghaiensis , 21.0%, 172/818), were collected in 4 villages in Shiqu county. Only Bartonella melophagi was detected in tick samples with a total prevalence of 30.1% (246/818). Significant difference was observed (P<0.05) between D.everestianus (17.0%) and H.qinghaiensis (79.1%).The infection rates of Bartonella spp. in ticks from Arizha, Maga, Derongma and Changxgma villages were 4.8%, 76.8%, 12.5% and 18.0%, respectively. Compared with other villages, the infection rate of Bartonella spp. in Maga was higher (P<0.01). As for plateau pika, total infection rate of Bartonella spp was 24.1%, with 20.8% (15/72), 30.9% (25/81), 13.8% (9/65) and 29.4% (20/68) in Arizha, Maga, Derongma and Changxgma, respectively. Totally, B. queenslandensis , B.grahamii and two unvalidated Bartonella species were detected. No significant difference in infection rates was observed (P>0.05) between theses study sites. Conclusion At present, only D.everestianus and H.qinghaiensis were found in Shiqu county with high infection of Bartonella spp. in theses ticks and plateau pika. The threats to public health by these Bartonella species should be monitored.