Thursday, October 7, 2021 (HealthDay News) — Scientists in Japan have discovered another tick-borne virus that can make people sick.
Transmitted by tick bites, the Yezo virus causes fever and lowers platelets and white blood cells.
“At least seven people have been infected with this new virus in Japan since 2014, but so far no deaths have been confirmed,” said Keita Matsuno, a virologist with the International Institute for Zoonoses Control at Hokkaido University.
“It is very likely that the disease is present outside of Hokkaido, so we need to urgently investigate its spread,” Matsuno said in a university news release.
In 2019, a 41-year-old man was hospitalized with fever and leg pain after being bitten by a tick while walking through a local forest in Hokkaido. He was treated and released from hospital two weeks later, but tests showed that he was not infected with any known tick-borne viruses in the area.
The following year, another patient was treated for similar symptoms after a tick bite.
Genetic analyzes of viruses in blood samples from the two patients identified Yezo virus. Yezo is a historical Japanese name for Hokkaido, a large island in northern Japan.
Tests of blood samples from other hospital patients who have had similar symptoms after tick bites since 2014 have revealed five more patients with Yezo virus.
The researchers then moved on to find the source of the virus and found antibodies to the virus in Hokkaido sika deer and raccoon, and Yezo RNA in three major species of ticks in Hokkaido, according to the study. It was recently published online in the magazine Nature Connections.
“Iso virus appears to have proven circulating in Hokkaido, and the virus is highly likely to cause disease when transmitted to humans from animals by ticks,” Matsuno said.
The researchers said that more hospitals should test for the virus in patients who show symptoms suggesting infection with Yezo.
Yezo virus is closely related to Solina virus and Tamdy virus, which were discovered in Romania and Uzbekistan, respectively. There are reports that the TMD virus has caused severe fevers in people in China.
Tick-borne diseases are a global threat. In the United States, Lyme disease, Babesiosis, and Rocky Mountain spotted fever are among the diseases to watch out for.
The US National Institute of Allergy and Infectious Diseases has more on tick-borne diseases.
Source: Hokkaido University, press release, October 3, 2021