Molecular analysis on the S gene of three Crimean-Congo hemorrhagic fever virus strains in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To compare the molecular characteristics of 3 Crimean-Congo hemorrhagic fever viruses(CCHFV) isolated in Xinjiang province.</p><p><b>METHODS</b>YL05035, YT05099 and LT05146 were isolated in 2005 from Hyalomma ticks and viral RNA was extracted from suckling mouse brains infected with these three strains respectively. The polymerase chain reaction(PCR) products of S segments from the 3 strains of CCHFV were directly sequenced.</p><p><b>RESULTS</b>The full-length'S RNA from the 3 strains of CCHFV all comprised 1673 nucleotides with ORF of them including 1449 nucleotides and encoding a protein which comprised 482 amino acids in a viral complementary sense. The sequences indicated that the three strains of CCHFV isolated from ticks in Xinjiang province were highly homologenic. Data from the phylogenetic analysis showed that the obtained sequences were identical. The homology between 3 strains of CCHFV was 99.5%. Their homologies compared with that of the other strains isolated from other region of Xinjiang were also high at nucleotide levels (92.7%-99.8%). The three strains which were clustered together with 7001 strain and 79121 strain (isolated from patient and rat in Xinjiang respectively) was only different by 2%-3%. The genetic difference from the prototype CCHFV Nigerian strain IBAR10200 was 13%. In comparison, the Nigerian CCHFV tick isolate was more divergent when compared with the reference China strains 66019 and with the three variants mentioned above.</p><p><b>CONCLUSION</b>The CCHFV isolated from China comprised a group of genetically high conserved strains.</p>

Geography and host distribution of Crimean-Congo hemorrhagic fever in the Tarim Basin / 中华流行病学杂志

<p><b>OBJECTIVE</b>To determine the infective status and natural distribution of Xinjiang hemorrhagic fever (XHF; Crimean-Congo hemorrhagic fever, CCHF) in ticks, rodents and livestock in the Tarim Basin.</p><p><b>METHODS</b>The pathogenic materials of ticks or rodents' viscera and blood samples of sheep were inoculated into sucking mouse of 24 to 48-hour old. Materials with typical clinic symptoms were identified with RPHA and IFA. RT-PCR was taken to detect special S gene segment of Crimean-Congo hemorrhagic fever virus (CCHFV) in the objective material.</p><p><b>RESULTS</b>All the samples of ticks, rodents' viscera and blood samples of sheep from 21 counties (cities) in the Tarim Basin were divided into 422 groups and inoculated into sucking mouse at laboratory. 49 materials with typical clinic symptoms were obtained. The morbidity rate with typical clinic XHF was high in Bachu, Yuli, Yutian and Ruoqiang. There were 43 samples identified with RPHA with 6 positive samples and positive rate of 1.4%. The materials with positive RPHA were found in Yuli, Luntai and Yutian. 42 samples were identified with IFA and 13 positive samples with the positive rate of 3.1%. The positive materials of IFA were found in Bachu, Yuli, Minfeng, Luntai and Yutian. 32 samples were detected with RT-PCR and there were 31 samples with special S gene segment of CCHFV (329- 548 nt). The positive materials was widely distributed in Aksu, Awat, Bachu, Luopu, Yuli, Minfeng, Qiemo, Ruoqiang, Luntai and Yutian. The highest infective rate was in Hyalomma asiaticum kozlovi, and followed by sheep. S gene segment was detected in viscera of M. meridianus.</p><p><b>CONCLUSION</b>XHF relied on the river in the southern part of Xinjiang and distributed in the areas with Populus euphratica shrub in desert and oasis in the Tarim Basin. The main vector and host were Hyalomma asiaticum kozlovi. Livestock such as sheep, camel, L. yarkandensis, M. meridianus and Euchoreutes naso could serve as the deposited host of XHF.</p>