Multispacer Typing (MST) of Spotted Fever Group Rickettsiae Isolated from Humans and Rats in Chengmai County, Hainan Province, China

Human Spotted Fever Group Rickettsia Infecting Yaks (Bos grunniens) 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) Rickettsia spp. in the area is limited. This study performed screenings, and detected the DNA of human pathogen, SFG Rickettsia spp., with 11.3% (25/222) infection rates in yaks (Bosgrunniens). BLASTn analysis revealed that the Rickettsia sequences obtained shared 94.3–100% identity with isolates of Rickettsia spp. from ticks in China. One Rickettsia sequence (MN536161) had 100% nucleotide identity to two R. raoultii isolates from Chinese Homo sapiens, and one isolate from Qinghai Dermacentorsilvarum. Meanwhile, another Rickettsia sequence (MN536157) shared 99.1–99.5% identity to one isolate from Dermacentor spp. in China. Furthermore, the phylogenetic analysis of SFG Rickettsia spp. ompA gene revealed that these two sequences obtained from yaks in the present study grouped with the R. slovaca and R. raoultii clades with isolates identified from Dermacentor spp. and Homo sapiens. Our findings showed the first evidence of human pathogen DNA, SFG Rickettsia spp., from animals, in the QTPA.

Test of 259 serums from patients with arthritis or neurological symptoms confirmed existence of Lyme disease in Hainan province, China

Indirect Fluorescent-Antibody Test (IFA), Western Blot (WB) and Nested-PCR were applied to identify the Borrelia burgdorferi in human serum samples in Hainan province. A total of 259 serum samples were collected from Sanya Peoples' Hospital, Hainan province. These samples were examined for the presence of B. burgdorferi serologically and etiologically by the two tier tests (IFA and WB) and Nested-PCR. 43 in total of 259 serum samples were tested positive by IFA assay, the positive rate was 16.6%. Among 43 IFA-positive samples, 6 were identified positive by WB. Nested-PCR were also used to test B. burgdorferi DNA in 259 serum samples at the same time, 27 samples were tested positive with positive rate of 10.42%. It is the first time to confirm that there are Lyme patients in Hainan province of China. The study suggested that Lyme disease should be commonly considered by clinicians with the patients who had correlated symptoms with lyme disease in Hainan.