This report describes a novel tickborne orthonairovirus species identified in patients presenting with an acute febrile illness in China.

This report describes a novel tickborne orthonairovirus species identified in patients presenting with an acute febrile illness in China.

In June 2019, a patient presented with persistent fever and multiple organ dysfunction after a tick bite at a wetland park in Inner Mongolia. Next-generation sequencing in this patient revealed an ...

A new pathogenic orthonairovirus was identified in patients with a febrile illness in China. This virus was found in Haemaphysalis longicornis ticks in the same region.

This report describes a novel tickborne orthonairovirus species identified in patients presenting with an acute febrile illness in China.

A case report published in the New England Journal of Medicine describes a previously unidentified orthonairovirus, dubbed Wetland virus (WELV), in a man bitten by a tick at a wetland park in Inner Mo...

This report describes a novel tickborne orthonairovirus species identified in patients presenting with an acute febrile illness in China.

A growing number of emerging and re-emerging tick-borne orthonairoviruses belonging to the Sulina and Tamdy genogroups have recently been identified in association with febrile diseases in East Asia. Yezo virus (YEZV) is one such viruses and is genetically distinct from well-characterized Crimean-Congo hemorrhagic fever virus. Orthonairovirus glycoproteins (Gn and Gc) expressed from a single glycoprotein precursor (GPC) gene mediate interaction with host cells, yet the organization and functions of the YEZV glycoproteins remain largely undefined. To characterize YEZV glycoproteins in the context of infection, we developed a reverse genetics system that enables recovery of recombinant YEZV entirely from cloned cDNAs. The recombinant wild-type virus exhibited growth properties comparable to those of the parental isolate in vitro and maintained pathogenicity in vivo. Proteomic analysis of purified virus particles produced in mammalian cells showed that peptide coverage of GPC-derived products began at residue 69. We therefore used the reverse genetics system to examine the functional importance of the GPC subregion upstream of residue 69. A mutant with a deletion of GPC residues 28 to 68 (rYEZV GPC{Delta}28-68), which retained the predicted signal peptide, was successfully recovered, suggesting that this subregion is dispensable for producing infectious virus. rYEZV GPC{Delta}28-68 propagated at levels comparable to those of the wild-type virus in mammalian cells and exhibited similar pathogenicity in a mouse model. Interestingly, the mutant reached lower viral titers in tick-derived ISE6 cells and in ticks in vivo, suggesting that this N-terminal subregion may contribute to virus replication in ticks. Together, these findings demonstrate the utility of the newly established reverse genetics system for dissecting the functions of the YEZV glycoproteins in mammalian and tick systems.

A growing number of emerging and re-emerging tick-borne orthonairoviruses belonging to the Sulina and Tamdy genogroups have recently been identified in association with febrile diseases in East Asia. Yezo virus (YEZV) is one such viruses and is genetically distinct from well-characterized Crimean-Congo hemorrhagic fever virus. Orthonairovirus glycoproteins (Gn and Gc) expressed from a single glycoprotein precursor (GPC) gene mediate interaction with host cells, yet the organization and functions of the YEZV glycoproteins remain largely undefined. To characterize YEZV glycoproteins in the context of infection, we developed a reverse genetics system that enables recovery of recombinant YEZV entirely from cloned cDNAs. The recombinant wild-type virus exhibited growth properties comparable to those of the parental isolate in vitro and maintained pathogenicity in vivo. Proteomic analysis of purified virus particles produced in mammalian cells showed that peptide coverage of GPC-derived products began at residue 69. We therefore used the reverse genetics system to examine the functional importance of the GPC subregion upstream of residue 69. A mutant with a deletion of GPC residues 28 to 68 (rYEZV GPC{Delta}28-68), which retained the predicted signal peptide, was successfully recovered, suggesting that this subregion is dispensable for producing infectious virus. rYEZV GPC{Delta}28-68 propagated at levels comparable to those of the wild-type virus in mammalian cells and exhibited similar pathogenicity in a mouse model. Interestingly, the mutant reached lower viral titers in tick-derived ISE6 cells and in ticks in vivo, suggesting that this N-terminal subregion may contribute to virus replication in ticks. Together, these findings demonstrate the utility of the newly established reverse genetics system for dissecting the functions of the YEZV glycoproteins in mammalian and tick systems.

We analyzed 20 patients tested positive for infections of Yezo virus, an emerging tick-borne orthonairovirus in Far East Asia. Yezo virus infection cases w

A new pathogenic orthonairovirus was identified in patients with a febrile illness in China. This virus was found in Haemaphysalis longicornis ticks in the same region.

Chinese researchers working with collaborators in the United States have identified a previously unrecognized tick-borne virus that appears to be responsible for hundreds of febrile illnesses in China. Named Asian longhorned tick nairovirus (ALTNV), the pathogen belongs to the Orthonairovirus genus and was detected during surveillance of people who developed fever after tick exposure. Scienti...

We produced spatial datasets of the known distribution of Orthonairovirus haemorrhagiae (formerly Crimean-Congo haemorrhagic fever virus, CCHFV) by compiling human cases, virus isolations, and serolog...

Crimean-Congo hemorrhagic fever virus (CCHFV) classified in the Orthonairovirus haemorrhagiae species (genus Orthonairovirus, family Nairoviridae) is a tick-borne virus, known to cause severe hemorrha...

Researchers led by the State Key Laboratory of Pathogen and Biosecurity in Beijing have named the newly identified orthonairovirus Asian longhorned tick nairovirus (ALTNV). The discovery, reported in the New England Journal of Medicine, grew out of efforts to understand why about 30% of patients with symptoms suggestive of Dabie bandavirus (DBV) infection test negative for the tick-borne hemorrhagic fever. A Search for the Cause of Unexplained Tick Illness DBV causes severe fever with thrombocytopenia syndrome (SFTS), a potentially deadly disease found across Asia. The infection has a case-fatality rate of 10% to 30%. Thrombocytopenia refers to an abnormally low level of platelets, the blood cells involved in clotting. The World Health Organization has identified DBV as a priority pathogen for research. To investigate unexplained cases, researchers collected samples from people who had been bitten by ticks and were treated at sentinel hospitals in regions of China where tick-borne viruses are known to circulate. Using RNA sequencing and viral isolation, the team detected the previously unknown virus. "The cocirculation of ALTNV and DBV in the same areas, coupled with their shared tick vector, underscores the need for improved differential diagnosis between infections with these viruses in regions where SFTS is...

This report describes a novel tickborne orthonairovirus species identified in patients presenting with an acute febrile illness in China.

A new pathogenic orthonairovirus was identified in patients with a febrile illness in China. This virus was found in Haemaphysalis longicornis ticks in the same region.

This report describes a novel tickborne orthonairovirus species identified in patients presenting with an acute febrile illness in China.

Un nouveau virus, le XCV, récemment découvert en Chine, suscite l'inquiétude après avoir infecté au moins 26 personnes. Transmis par des tiques, ses symptômes varient de la fièvre à de graves complications, nécessitant parfois une hospitalisation.   par Pierre G. 14 janvier 2025, 15h29   Image : ...