China identifies new tick-borne virus

The virus, named Asian Longhorned Tick Nairovirus (ALTNV), belongs to the Orthonairovirus group and has been linked to low platelet counts and laboratory signs of liver injury or inflammation, according to a new study.

Since 2009, Chinese researchers have been investigating patients with unusual illnesses, including severe fever with thrombocytopenia syndrome (SFTS), a potentially serious tick-borne disease.

“Thrombocytopenia means a low platelet count, so these patients were bleeding, and the mortality rate was around 30%, which is very high,” said Sharon Nachman, chief of pediatric infectious diseases at Stony Brook Children’s Hospital in New York. She noted that researchers therefore continued to monitor these patients.

Many of the cases were associated with Dabie bandavirus (DBV), the virus responsible for SFTS, a tick-borne hemorrhagic fever. However, DBV was not the most common virus detected among the patients.

After extensive testing of blood samples and viral fragments, researchers identified ALTNV, which was found to be genetically distinct from DBV.

Researchers from Beijing’s State Key Laboratory of Pathology and Defense Biology detected ALTNV in 10.4% of 3,163 patients who had been exposed to tick bites. Patients infected with both ALTNV and DBV were more likely to develop respiratory problems and kidney complications. Seven of these co-infected patients, or 18.4%, died during the study period.

The researchers concluded that the presence of ALTNV and DBV in the same regions, combined with their association with the same tick vector, highlights the need for improved differential diagnosis between the two infections in areas where SFTS is endemic.

Symptoms and Treatment

ALTNV infection can initially resemble influenza, causing fever, muscle aches and fatigue, and in some cases respiratory symptoms.

Although ALTNV infection can lead to a decline in platelet levels, the study did not link the virus alone to severe bleeding or death. The fatal cases involved patients who were also infected with DBV.

Because symptoms caused by tick-borne viruses can overlap with those of many other infections, Nachman stressed the importance of identifying the specific virus involved. Effective antiviral drugs are available for influenza, she noted, but similar treatments are unavailable for many tick-borne viruses, including the newly identified virus.

For most patients, treatment currently consists of supportive care to manage symptoms. Identifying the underlying infection is also important to avoid inappropriate treatment, particularly antibiotics, which target bacteria rather than viruses.

How to Prevent Tick Bites

Experts recommend several measures to reduce the risk of tick bites:

Wear long clothing and tuck trousers into socks when outdoors.

Use insect repellent on exposed skin for adults; for young children, apply repellent to clothing instead.

Check the skin carefully for attached ticks, particularly after hiking or walking in areas where ticks may be present.

Removing ticks promptly is important because the longer an infected tick remains attached, the greater the potential risk of pathogen transmission.