Scientists Identify a New Tick-Borne Virus That Can Worsen a Deadly Illness

Researchers from Beijing's State Key Laboratory of Pathogen and Biosecurity have identified a novel virus transmitted to humans by ticks, found in the blood of patients with a history of tick bites, particularly from the Asian longhorned tick (Haemaphysalis longicornis). The study, published in the New England Journal of Medicine, followed a screening of 3,163 people with symptoms of the known Dabie bandavirus (DBV), also called severe fever with thrombocytopenia syndrome (SFTS).

Researchers were puzzled that 10.4% of the screened patients tested negative for DBV despite matching symptoms, and further investigation uncovered an entirely different pathogen delivered by the same ticks. The newly identified virus, now named the Asian longhorned tick nairovirus (ALTNV), belongs to the genus Orthonairovirus and produces symptoms resembling influenza A, including fever, fatigue and gastrointestinal upset.

"These findings provide evidence of ALTNV as a recently identified emerging tick-borne orthonairovirus associated with human febrile illness," the researchers wrote in their paper. "Coinfection with DBV appears to exacerbate disease severity." Among the study's patients, 38 were found to be infected with both ALTNV and DBV, and these co-infected patients showed significantly more serious respiratory issues and kidney impairment; seven of them died.

DBV itself has a fatality rate as high as 30% and is difficult to treat, since it is not a bacterial infection and antibiotics have no effect against it, leaving the immune system to fight it unaided. The researchers noted that the co-circulation of ALTNV and DBV in the same areas, sharing the same tick vector, underscores the need for improved differential diagnosis between the two infections in regions where SFTS is endemic. There is currently no treatment for either ALTNV or DBV.