A new tick-borne virus that causes a severe flu-like illness has been discovered in China, including in Hubei province, which is home to Wuhan, where the Covid outbreak began.
In a research article, scientists in Beijing said the virus, which they named Asian longhorned tick nairovirus (ALTNV), had been detected in 329 Chinese patients.
The individuals lived in four provinces across eastern and central China.
Patients suffered from gastrointestinal symptoms and a low platelet count, which can cause potentially fatal internal bleeding.
Scientists found the Asian longhorned tick was most likely to carry the new virus, a common tick in China and East Asia that can swell to up to 0.4 inches long after consuming a blood meal.
This tick has also been reported across 21 states in the US, particularly in Northeastern and Southern areas, where it is considered an invasive species.
It is not clear whether the new virus is also in the US.
None of the patients infected with ALTNV – and no other viruses – died, but seven patients infected with the new virus and another virus died. Researchers said the first case of ALTNV dated back to 2009.
Researchers are warning over a new tick-borne virus. Shown above is the Asian longhorned tick
In East Asia, patients bitten by ticks can be infected by dabie bandavirus (DBV) – also called severe fever with thrombocytopenia syndrome – a rare but serious infection where patients suffer from a fever and then potentially fatal internal bleeding.
Already been reported across China, South Korea, Japan and other Asian countries – but not in the US – infections are serious and have a fatality rate of about 15 percent.
But researchers have also noted that about 30 percent of patients reported to have DBV – based on similar symptoms, such as a fever – never tested positive for the virus.
It led researchers in Beijing to analyze samples from suspected and confirmed patients, which led to the discovery of ALTNV, the new virus.
In the study, published in the New England Journal of Medicine, researchers analyzed samples from 3,163 people who reported a fever after a tick bite across four provinces and found 10.4 percent – or 329 – tested positive for the new virus.
The four provinces the patients lived in were Henan, Hubei, Anhui and Shandong.
Of the 56 patients only infected with ALTNV who had details on symptoms available, after fever, the second most common symptom was fatigue, suffered by 84 percent of patients, and gastrointestinal issues, suffered by 80 percent of patients.
A further 38 percent had thrombocytopenia, a low platelet count that can cause fatal internal bleeding.
It was not clear why this was the case, but tick-borne viruses – such as DBV – can trigger immune cells to destroy platelets. Platelets are tiny fragments in the blood that help to stop bleeding.
The above map, published in the study, shows the locations of patients who tested positive for ALTNV. A sentinel hospital is one that provided data to be analyzed in the study
The above map, from US officials, shows where populations of long horned ticks have become established in the US. It is not clear whether these ticks are also carrying the virus
In the group, researchers said 38 patients were infected with DBV and ALTNV. Of these, seven individuals, or 18.4 percent, died.
Patients infected with both viruses were more likely to report severe symptoms including respiratory problems and kidney impairment.
It was not clear whether cases of the disease were currently rising in China or which tick had bitten each patient. It also was not clear what GI symptoms they had or what treatment they received.
But for patients with DBV, patients are treated using IV and blood transfusions. There are no specific treatments for DBV or ALTNV.
In a follow-up analysis, researchers then analyzed samples from 47,000 ticks that were collected from 15 provinces in China.
Overall, 1.3 percent of the ticks tested positive for ALTNV. Of the Asian longhorned ticks, 1.75 percent tested positive for the virus.
In a further study, researchers also found that, in a lab, Asian longhorned ticks could transmit the virus to mice, suggesting they may also be able to spread it to humans.
Writing in the research article, Dr Xiao-Ai Zhang, a biosecurity expert, and the other authors said: ‘These findings provide evidence of ALTNV as a recently identified emerging tick-borne [virus] associated with human [fever].
‘Coinfection with DBV appears to exacerbate disease severity.’
The Asian longhorned tick was first detected in the US in November 2017 in Hunterdon County, in the western area of New Jersey.
Also called the bush, cattle or scrub tick, it has now been collected in areas from New York to as far south as Georgia and Midwestern states such as Missouri. It has become established in other countries, including Australia and New Zealand.
