Yezo Virus: Previously Unknown Virus Linked To 'Emerging' Infectious Disease Discovered In Japan

Photo taken at the Dutch National Institute for Public Health and the Environment (RIVM) in Bilthoven shows tick specimens used for a study on the new TBE tick virus. 18/08/2016. (Photo: Getty Images/ AFP/ Robin Van Lonkhuijsen)



Key Points


  • Researchers identified a new virus that can infect humans


  • They detected the virus RNA in "three major tick species"


  • Seven cases have been reported since 2014



A novel virus that can be transmitted by tick bites has been discovered in Japan. Dubbed Yezo virus (YEZV), it can cause fever and other symptoms in humans.



A case of the mysterious disease was recorded in 2019 after a 41-year-old man was admitted to a hospital with symptoms, including fever and leg pain, Hokkaido University noted in a news release. The man was bitten by an "arthropod believed to be a tick," but tests revealed he was not infected with any of the known viruses carried by ticks in the region.



Although the man was discharged from the hospital after two weeks, another case of the mysterious disease was reported a year later, with the patient displaying similar symptoms.





Novel orthonairovirus




In a study, published in the journal Nature Communications, a team of researchers identified the new orthonairovirus likely behind the illnesses through genetic analysis of the blood samples collected from the two patients.

They also tested blood samples of 248 patients suspected of having a tick-borne disease and found that in total, there were actually seven cases from 2014 to 2020.



"YEZV is phylogenetically grouped with Sulina virus detected in Ixodes ricinus ticks in Romania," the researchers wrote.

The name of the novel virus is a reference to the historical Japanese name of Hokkaido, the place where the disease was discovered.



To determine the natural reservoir of the virus in Hokkaido, the team screened serum samples that were collected from wild animals in Hokkaido from 2010 to 2020. They found antibodies to YEZV in Hokkaido shika deer and raccoons, and the YEZV RNA in "three major tick species" collected from 2016 to 2020.



"We demonstrated that at least seven patients were infected with YEZV since 2014, and that wild animals and ticks may be potential reservoirs for the virus, suggesting that YEZV infection is endemic in this area," the researchers wrote.







Source: International Business Times_ Science section





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