New Tick-Borne Virus Identified in China Shows Distinct Clinical Features

Researchers in China have reported the discovery of a new virus, named Asian longhorned tick nairovirus (ALTNV), in patients with a history of tick exposure. The findings add to the understanding of tick-borne diseases and their potential impact on human health.

ALTNV was identified through metatranscriptomic sequencing and virus isolation in individuals who tested negative for Dabie bandavirus (DBV) infection. The virus was classified within the Orthonairovirus genus and shares less than 80% amino acid similarity with other known orthonairoviruses.

Testing of 3,163 patients with fever and tick exposure revealed that 10.4% were positive for ALTNV by RNA or IgM detection. Among those who did not have DBV, the rate of ALTNV positivity was 15.1%.

In a group of 56 patients with ALTNV infection only, the most frequent symptoms included fatigue, gastrointestinal issues, low platelet counts, and elevated liver enzymes. All individuals in this group recovered without lasting effects.

What the numbers show

• 10.4% of 3,163 febrile patients with tick exposure tested positive for ALTNV.
• 1.3% of 47,428 ticks sampled carried ALTNV RNA.
• 18.4% of patients coinfected with ALTNV and DBV died.

Coinfection with both ALTNV and DBV was observed in 38 patients. This group experienced higher rates of respiratory symptoms and kidney impairment compared to those with only one infection. Seven of the coinfected patients died, representing 18.4% of that group.

Sampling of ticks across 15 provinces found ALTNV RNA in 1.3% of 47,428 specimens, with the highest detection rate in Haemaphysalis longicornis ticks at 1.8%. Laboratory studies confirmed that this tick species can transmit ALTNV to mice.

ALTNV's genetic profile places it within the Nairoviridae family, but its amino acid sequence is less than 80% identical to other orthonairoviruses, indicating a distinct lineage. The research highlights the importance of monitoring tick-borne viruses in regions where human exposure is common.

All patients with ALTNV infection alone recovered fully, while those with coinfection experienced more severe outcomes. Ongoing surveillance and further research will help clarify the clinical significance and transmission patterns of ALTNV in affected areas.

* This article is based on publicly available information at the time of writing.