Chinese researchers have identified a new tick-borne virus, named the Asian longhorned tick nairovirus (ALTNV), after investigating years of unexplained illnesses in patients bitten by ticks. The virus, part of the orthonairovirus group, causes flu-like symptoms, fatigue, gastrointestinal upset, reduced blood platelet counts and signs of liver inflammation, and its discovery highlights how many undiagnosed tick-borne infections may still be circulating, particularly in regions where similar diseases are already common.

Scientists from the State Key Laboratory of Pathogen and Biosecurity in Beijing found ALTNV in 10.4% of 3,163 tick-bite patients tested since researchers began tracking mysterious illnesses in 2009. The virus is genetically distinct from Dabie bandavirus (DBV), which causes severe fever with thrombocytopenia syndrome and carries a mortality rate of around 30%; patients co-infected with both viruses were more likely to suffer respiratory and kidney complications, and seven of these (18.4%) died during the study. Experts note there is no specific antiviral for ALTNV, so treatment relies on supportive care, and they recommend standard tick-prevention measures such as covering skin, using repellents and checking for and promptly removing ticks after outdoor activity. The findings were published this week in the New England Journal of Medicine.