Genetic Characterization of the M RNA Segment of Crimean Congo Hemorrhagic Fever Virus Strains, China

We report the genetic characterization of the M RNA segment of Crimean Congo hemorrhagic fever virus (CCHFV). Two CCHFV strains isolated in Xinjiang Province, a region endemic for CCHF in northwestern China, were studied. These strains, designated BA66019 and BA8402, were isolated in 1965 and 1984 from a CCHF patient and Hyalomma ticks, respectively. Viral RNA was extracted from suckling mouse brains infected with these two strains, amplified, and sequenced. The full-length M RNA, consisting of 5.3 kb, was determined for both strains. The coding nucleotide sequences of the two strains differed from each other by 17.5% and from the reference CCHFV strain IbAr10200 by a mean of 22%, suggesting that the genus Nairovirus comprises a group of genetically highly diverse strains

Epidemiology and Phylogenetic Analysis of Crimean-Congo Hemorrhagic Fever Viruses in Xinjiang, China▿

In 2004 and 2005, an epidemiological survey of Crimean-Congo hemorrhagic fever virus (CCHFV) was conducted in Xinjiang, China. A total of 5,629 serum samples of human and livestock were collected and tested for the CCHFV antibody, and 17,319 ticks were collected for viral identification. Reverse passive hemagglutination inhibition assays showed that the average prevalence of CCHFV antibody was 1.7% for the humans and 12.7% for the livestock. A relatively high antibody prevalence, ranging from 19.1% to 23.4%, was found in the livestock of the northwest, southwest, and northeast parts of the Tarim Basin. When the ticks were pooled to inoculate suckling mice, followed by reverse transcription-PCR (RT-PCR) to detect CCHFV RNA, the average RT-PCR-positive rates for Hyalomma asiaticum kozlovi and H. asiaticum asiaticum were 12.9% and 2.6%, respectively. A significant correlation was found between the antibody prevalence in the livestock and the CCHFV prevalence in H. asiaticum of the same geographic region. No CCHFV RNA was detected in Dermacentor nivenus, Rhipicephalus turanius, or Rhipicephalus sanguineus. A total of 27 partial S segments of CCHFVs were sequenced and used for phylogeny analysis. All but one Chinese isolate grouped into the Asia 1 clade, which contains the strains from Xinjiang and Uzbekistan, while the other strain, Fub90009, grouped with strains from the Middle East