Holten et al.
A case of fatal haemorrhagic fever associated with tick-borne encephalitis virus infection. Int J Infect Dis. Published online July 16, 2025. doi:10.1016/j.ijid.2025.107989
Some flaviviruses, such as Omsk haemorrhagic fever virus and Dengue virus, are known to cause haemorrhagic fever. Similar severe manifestations, including fatal outcomes, have also been reported in rare cases following infection with the Far Eastern subtype of tick-borne encephalitis (TBE) virus in patients from Novosibirsk, Russia.
Recently, a case of haemorrhagic fever was reported in a Norwegian woman in her late fifties who was immunocompromised due to multiple underlying conditions. The patient initially presented with fever, malaise, and ecchymosis on the trunk. By the second day of hospitalization, she showed signs of early confusion. On day four, she was transferred to the intensive care unit, and by day five, she experienced an acute circulatory collapse.
A CT scan revealed a large retroperitoneal hematoma with active bleeding from the third lumbar artery. On the following day, continued hemorrhaging was observed from a second lumbar artery and a circumflex iliac artery. The expanding hematoma compressed the inferior vena cava, and the patient ultimately succumbed to multiorgan failure.
TBE virus was detected in both plasma and cerebrospinal fluid using PCR. Whole-genome sequencing identified the virus as clustering with the Kumlinge strain from Finland, belonging to the European subtype.
This is the first documented case of a monophasic, haemorrhagic fever associated with the European subtype of TBE virus.