SEOUL: The South Korean health authorities said on May 7 they had confirmed the country’s first locally detected human case of Oz virus infection, a tick-borne disease previously found here only in an imported case.
The patient, a woman in her 80s, was tested in November after doctors initially suspected severe fever with thrombocytopenia syndrome, or SFTS.
She had fever, chills and muscle pain, and had no history of overseas travel, according to the Korea Disease Control and Prevention Agency (KDCA).
Her SFTS test came back negative. She received treatment and made a full recovery.
The case marks the first time the Oz virus has been detected in a patient in South Korea with no overseas travel history. The only previous confirmed case here involved a person who was infected while travelling in Japan in July 2023.
Oz virus is an RNA virus first identified in Japan in 2018 from Amblyomma testudinarium ticks. It drew attention as a potentially human-infecting tick-borne virus after Japan reported a fatal human infection in 2023.
Cases have been rare globally, with previous infections reported only in Japan.
The latest finding suggests that a local occurrence of Oz virus infection in South Korea cannot be ruled out. The KDCA said doctors should consider the possibility of Oz virus infection when the cause of fever remains unclear in patients who have been bitten by ticks.
Symptoms of Oz virus infection include fever, chills and muscle pain, similar to those of SFTS, making the two difficult to distinguish without additional testing.
The KDCA said it has been monitoring infectious diseases reported overseas but not yet confirmed in South Korea, as climate change and other factors may alter the habitats of ticks and other disease vectors.
The agency conducts quarterly follow-up analyses on samples from suspected infections that test negative for diseases such as SFTS.
The aim is to determine whether viruses reported in small numbers in nearby countries, including Japan and Taiwan, have been introduced into South Korea or begun occurring locally.
The latest case was identified in March during testing of samples from unexplained infections that had tested negative for initially suspected diseases. The KDCA said it tested for about 10 viruses during the analysis. - The Korea Herald/ANN
