Diversity of spotted fever group Rickettsia infection in hard ticks from Suifenhe, Chinese-Russian border.

In order to investigate the diversity of spotted fever group (SFG) Rickettsia infection in hard ticks, ticks were harvested from the forest areas in Suifenhe city, along the Chinese-Russian border and conventional PCR was carried out using universal SFG Rickettsia primers targeting gltA and ompA genes to screen for their infection with SFG Rickettsia organisms. Results showed that of the 215 ticks belonging to Ixodes persulcatus, Haemaphysalis concinna and Haemaphysalis japonica Warburton, 1908 species, 138 (64.2%) were positive for SFG Rickettsia. Three species of SFG Rickettsia were detected, Rickettsia raoultii, Rickettsia heilongjiangensis and Candidatus Rickettsia tarasevichiae. No co-infection with different species of SFG Rickettsia was found in any individual tick among the three tick species. We detected more than one SFG Rickettsia species in ticks from each of the three tick species with an overlapping distribution and potentially similar transmission cycles of SFG Rickettsia in the areas surveyed. Consequently, different pathogenic rickettsial species may be involved in human cases of rickettsiosis after a bite of the three above-mentioned tick species in that area Rickettsia.

Co-circulation of Hantaan, Kenkeme, and Khabarovsk Hantaviruses in Bolshoy Ussuriysky Island, China.

Hemorrhagic fever with renal syndrome (HFRS) was first recognized in far eastern Asia in the 1930s, and has been highly prevalent in this region ever since. To reveal the molecular epidemiology of hantaviruses in this region, a total of 374 small mammals (eight species of rodents and one species of shrew) were captured in the Chinese part of the Bolshoy Ussuriysky Island (Heilongjiang Province). Hantavirus sequences were recovered from three striped field mice (Apodemus agrarius), 11 Maximowicz's voles (Microtus maximowiczii), and one flat-skulled shrew (Sorex roboratus). Genetic and phylogenetic analysis revealed the presence of three viruses: Hantaan virus (HTNV), Khabarovsk virus (KHAV), and Kenkeme virus (KKMV). HTNV sequences recovered from A. agrarius were closely related to those identified in Apodemus mice from the surrounding areas, while a new lineage of KHAV was present in M. maximowiczii. Additionally, while the viral sequences recovered from one flat-skulled shrew were most closely related to KKMV, their divergence to the prototype strain suggests that they represent a new viral subtype. Overall, these results suggest that Bolshoy Ussuriysky Island harbors considerable hantavirus diversity.

[Investigation on the vectors of Borrella burgdorferi and on the identification of the isolates along China-Russia border in Eastern Heilongjiang province, China].

OBJECTIVE: To explore the fact that the east border of Heilongjiang had been a lyme disease natural focus,we investigated the species and distribution of ticks and isolated bacteria from ticks and identified genomic species of Borrelia burdorferi sensu lato. This study provided evidence for prevention and control of lyme disease. METHODS: Ticks were caught by flagging method and Direct immunofluorescence method was used to detect the rate of bacteria borne by the tick. BSK UI culture medium was used to isolate the agent and Specific McAbs were used to identify the bacteria. SDS-PAGE protein profile and PCR-RFLP method were also used to identify the species of Spirochetes. RESULTS: Ticks, collected from China-Russia border of east Heilongiiang province were classified including Ixodes persulcatus Schulze, Dermacentor sivarum Olener, Haemaphysalis concinna Kock,and Haemaphysalis japonica Kock. We found that the distributon of ticks was different under different circumstances and the predominant species were also different in different ports. The rate of bacteria borne by Iodes persulaatus Schulze was 31.4% ,by Dermacentor sivarum Olener and Haemaphysalis concinna Kock were 2.2% and 3.8%, respectively. However,it was negative for Haenaphysalis japonica Kock. Spirochetes isolated from Ixodes persulcatus Schulze were collected from Dongning and Tongjiang while Genomic species of Spirochetes, isolated from ticks of the border belonged to B. garinii. CONCLUSION: All the results showed that the east border of Heilongjiang province was the natural focus of lyme disease.