Taxonomy of the order Bunyavirales: update 2019.

In February 2019, following the annual taxon ratification vote, the order Bunyavirales was amended by creation of two new families, four new subfamilies, 11 new genera and 77 new species, merging of two species, and deletion of one species. This article presents the updated taxonomy of the order Bunyavirales now accepted by the International Committee on Taxonomy of Viruses (ICTV).

Evaluation of the application value of a three-dimensional digital model of the knee in clinical practice.

OBJECTIVE: To compare the knee shape and bone parameters between knee prosthesis products from overseas companies and a Chinese patient's knee, and to apply the anatomical basis for Chinese knee prosthesis design. METHODS: Three-dimensional digital models were built, including prosthesis products for a normal adult. The relevant anatomy index was measured, and physical parameter, radiographic, geometric, knee kinematic, and distal geometry data were collected on the femur and tibia. RESULTS: The width of the femoral condyle (WFC), width of the medial femoral condyle (WMFC), width of the lateral femoral condyle (WLFC), depth of the intercondylar fossa (DICF), sagittal length of the medial femoral condyle (SLMFC), sagittal length of the lateral femoral condyle (SLLFC), angle of the medial femoral condyle (AMFC), and angle of the lateral femoral condyle (ALFC) in the femur and the transverse diameter (ML) and anteroposterior diameter (AP) of the tibial bone were measured. These parameters were significantly lower in the normal group compared with the prosthesis product model group. CONCLUSION: When using an imported knee prosthesis, the osteotomy angle may not fit perfectly. Use of an imported prosthesis may be an important factor in the increasing failure of knee arthroplasty in China.

Isolation, Characterization, and Phylogenetic Analysis of Two New Crimean-Congo Hemorrhagic Fever Virus Strains from the Northern Region of Xinjiang Province, China.

Crimean-Congo hemorrhagic fever (CCHF) caused by the CCHF virus (CCHFV) is a tick-borne natural focal disease with a mortality rate of approximately 50%. CCHFV is widely prevalent in Africa, southern Asia, the Middle East, and southeast Europe. CCHF outbreaks have been reported previously in Xinjiang province, China, especially in its southern region. Epidemiological surveys conducted on ticks and animals have revealed the presence of CCHFV strains in ticks, rodents, and infected individuals from cities and counties in southern Xinjiang. Phylogenetic analyses revealed that the Chinese CCHFV strains belong to one genotype, based on complete sequences of the S segments of its negative-stranded RNA genome. The present study reports two new CCHFV strains isolated from Hyalomma asiaticum asiaticum ticks collected from Fukang City and Wujiaqu City in the northern region of Xinjiang. Viral characteristics and their evolutionary relationships were analyzed through metagenomic and reverse-transcription PCR analyses; these analyses indicated that the genotype of both strains was different from that of other Chinese strains. Furthermore, previous reports of CCHFV in Xinjiang were reviewed and phylogenetic analyses were performed. CCHFV was found to prevail in Fukang City in Junggar Basin for more than 20 years, and that Fukang City and Wujiaqu City are considered natural reservoirs of different genotypes of CCHFV strains. Our findings facilitate the understanding of CCHFV distribution in Xinjiang province and provide insights into the evolutionary relationships among Chinese CCHFV strains.

A novel tick-borne phlebovirus, closely related to severe fever with thrombocytopenia syndrome virus and Heartland virus, is a potential pathogen.

Tick-borne viral diseases have attracted much attention in recent years because of their increasing incidence and threat to human health. Severe fever with thrombocytopenia syndrome phlebovirus (SFTSV) and Heartland virus (HRTV) were recently identified as tick-borne phleboviruses (TBPVs) in Asia and the United States, respectively, and are associated with severe human diseases with similar clinical manifestations. In this study, we report the first identification and isolation of a novel TBPV named Guertu virus (GTV) from Dermacentor nuttalli ticks in Xinjiang Province, China, where TBPVs had not been previously discovered. Genome sequence and phylogenetic analyses showed that GTV is closely related to SFTSV and HRTV and was classified as a member of the genus Phlebovirus, family Phenuiviridae, order Bunyavirales. In vitro and in vivo investigations of the properties of GTV demonstrated that it was able to infect animal and human cell lines and can suppress type I interferon signaling, similar to SFTSV, that GTV nucleoprotein (NP) can rescue SFTSV replication by replacing SFTSV NP, and that GTV infection can cause pathological lesions in mice. Moreover, a serological survey identified antibodies against GTV from serum samples of individuals living in Guertu County, three of which contained neutralizing antibodies, suggesting that GTV can infect humans. Our findings suggested that this virus is a potential pathogen that poses a threat to animals and humans. Further studies and surveillance of GTV are recommended to be carried out in Xinjiang Province as well as in other locations.

Dynamics of Yersinia pestis and its antibody response in great gerbils (Rhombomys opimus) by subcutaneous infection.

BACKGROUND: Rhombomys opimus (great gerbil) is a reservoir of Yersinia pestis in the natural plague foci of Central Asia. Great gerbils are highly resistant to Y. pestis infection. The coevolution of great gerbils and Y. pestis is believed to play an important role in the plague epidemics in Central Asia plague foci. However, the dynamics of Y. pestis infection and the corresponding antibody response in great gerbils have not been evaluated. In this report, animal experiments were employed to investigate the bacterial load in both the liver and spleen of infected great gerbils. The dynamics of the antibody response to the F1 capsule antigen of Y. pestis was also determined. METHODOLOGY: Captured great gerbils that tested negative for both anti-F1 antibodies and bacterial isolation were infected subcutaneously with different doses (10(5) to 10(11) CFU) of a Y. pestis strain isolated from a live great gerbil during routine plague surveillance in the Junggar Basin, Xinjiang, China. The clinical manifestations, changes in body weight, anal temperature, and gross anatomy of the infected animals were observed. The blood cell count, bacterial load, and anti-F1 antibody titers were determined at different time points after infection using a blood analyzer, plate counts, and an indirect hemagglutination assay, respectively. CONCLUSIONS/SIGNIFICANCE: The dynamics of bacterial load and the anti-F1 antibody concentration in great gerbils are highly variable among individuals. The Y. pestis infection in great gerbils could persist as long as 15 days. They act as an appropriate reservoir for plague in the Junggar Basin, which is part of the natural plague foci in Central Asia. The dynamics of the Y. pestis susceptibility of great gerbil will improve the understanding of its variable resistance, which would facilitate the development of more effective countermeasures for controlling plague epidemics in this focus.