A novel nairovirus associated with acute febrile illness in Hokkaido, Japan

Abstract

The increasing burden of tick-borne orthonairovirus infections, such as Crimean-Congo hemorrhagic fever, is becoming a global concern for public health. In the present study, we identify a novel orthonairovirus, designated Yezo virus (YEZV), from two patients showing acute febrile illness with thrombocytopenia and leukopenia after tick bite in Hokkaido, Japan, in 2019 and 2020, respectively. YEZV is phylogenetically grouped with Sulina virus detected in Ixodes ricinus ticks in Romania. YEZV infection has been confirmed in seven patients from 2014–2020, four of whom were co-infected with Borrelia spp. Antibodies to YEZV are found in wild deer and raccoons, and YEZV RNAs have been detected in ticks from Hokkaido. In this work, we demonstrate that YEZV is highly likely to be the causative pathogen of febrile illness, representing the first report of an endemic infection associated with an orthonairovirus potentially transmitted by ticks in Japan.

Mapping of Antibody Epitopes on the Crimean-Congo Hemorrhagic Fever Virus Nucleoprotein

“…In this study, we focused on antibody epitopes on CCHFV NP and the presence of shared epitopes with NSDV/DUGV NPs. However, it is also important to analyze the cross-reactivities of antibodies to other nairoviruses closely related to CCHFV, such as Hazara, Tofla, Meram, and Kupe viruses, while their pathogenic potential to humans is unclear [ 32 , 35 , 36 , 37 , 38 , 39 , 40 ]. Although several serological diagnostic assays for CCHF have been previously established, the cross-reactivity issue is still a potential weakness of the assays since the whole NP molecule is used as an antigen.…”

Spillover and spillback risks of ectoparasites by an invasive squirrel Callosciurus erythraeus in Kanto region of Japan

“…For example, severe fever with thrombocytopenia syndrome (SFTS) has recently become problematic as a tick-borne disease in Japan ( Kobayashi et al, 2020 ). Members of the genus Haemaphysalis , including H. flava , are thought to be potential vectors of the viruses that cause SFTS ( Ejiri et al, 2018 ; Kodama et al, 2021 ). SFTS is currently suspected to be associated with sika deer, whose numbers are recently increasing ( Lundu et al, 2018 ; Saijo, 2018 ; Yamaji et al, 2018 ; see also Doi et al, 2020 ), but other wild mammals can also become important reservoirs of the vector ticks.…”

Crimean-Congo hemorrhagic fever: a growing threat to Europe

“…Although clinically less significant, nairoviruses of different species including NSDV, Dugbe (DUGV), Erve (ERVEV), Kasokero (KASV), Tamdy (TAMV) have been associated with non-lethal diseases in humans [7]. New nairoviruses are continuously being reported [8][9][10][11] and some have been associated with human disease, like as the Yezo virus isolated from patients with thrombocytopenia and leukopenia in Japan and China [10,11].…”

“…Bien que cliniquement moins importants, des nairovirus de différentes espèces, dont les virus NSDV, Dugbe (DUGV), Erve (ERVEV), Kasokero (KASV), Tamdy (TAMV), ont été associés à des maladies chez l'homme, bien que les signes cliniques associés soient moins sévères que ceux retrouvés suite à une infection par le CCHFV [7]. Par ailleurs, de nouveaux nairovirus sont continuellement signalés [8][9][10][11], certains étant associés à des maladies humaines, comme le virus Yezo isolé chez des patients atteints de thrombocytopénie et de leucopénie au Japon et en Chine [10,11].…”