Discovery of a new tick-borne virus in China that causes thrombocytopenia

The discovered virus, called the Asian Longhorned Tick Nairovirus (ALTNV), which belongs to the Orthonairovirus group, was found to cause thrombocytopenia (low platelet count) in addition to the appearance of laboratory indicators of infection or inflammation in liver cells.

Since 2009, Chinese researchers have tracked patients with unusual illnesses, including severe fever with thrombocytopenia syndrome (SFTS).

“Thrombocytopenia is a low number of platelets, so these patients were bleeding, and the mortality rate was about 30%, which is very high,” said Dr. Sharon Nachman, chief of pediatric infectious diseases at Stony Brook Children’s Hospital in New York. “So they continue to follow these patients.”

Many of the cases were linked to the Dabi Pandavirus (DBV), or as it is known as the virus that causes severe fever with thrombocytopenia syndrome, a tick-borne hemorrhagic fever, but it was not the most common virus among patients. After extensive testing of blood samples and virus fragments, researchers identified the new virus, ALTNV, which is genetically different from DBV.

Researchers from the State Key Laboratory of Pathology and Defense Biology in Beijing identified the virus in 10.4% of 3,163 patients exposed to tick bites. Patients who were infected with both ALTNV and DBV were more likely to have respiratory problems and kidney complications, and seven of them (18.4%) died during the study period.

“The prevalence of ALTNV and DBV in the same regions, coupled with their sharing of the same tick vector, underscores the need to improve differential diagnosis between infections with these viruses in areas where high fever syndrome with thrombocytopenia is endemic,” the researchers concluded.

Symptoms and treatment

ALTNV can initially resemble the flu, causing fever, muscle aches, fatigue and sometimes respiratory symptoms.

Although ALTNV infection can cause a decrease in platelet counts, the study did not link the virus alone to severe bleeding or deaths, as the fatal cases included patients who were also infected with DBV.

Since the symptoms of tick-borne viruses can overlap with many infections, Nachman stressed the importance of identifying the specific virus, noting that effective antivirals exist for influenza, but are not available for many tick-borne viruses, including the newly discovered virus. She explained that for most patients, supportive care is provided to help manage symptoms, while avoiding giving the wrong medications, especially antibiotics that only work against bacteria and not viruses.

Prevention of tick bites

To avoid tick bites, Nachman recommends:

Wear long clothes and tuck your pants into socks.

Use insect repellents on the skin for adults, or on clothing for young children.

Check the skin constantly to remove any stuck ticks, especially after hiking or walking on the beach, because the presence of ticks for a longer period increases the risk of transmission of infection.

The results were published this week in the New England Journal of Medicine.