A new tick-borne virus which can cause deadly brain infections has been discovered in humans for the first time.
A 61-year-old man was found to have the Wetland virus after reportedly being bitten by ticks at a park in northern China. His symptoms included fever, a headache and bouts of vomiting which started about five days after his visit to the area.
The man was treated in the city of Jinzhou in June 2019, and the case has now been reported in the New England Journal of Medicine. His illness led to an investigation into the infection with Chinese researchers examining the link between ticks and animals.
It stated: “In June 2019, a patient presented with persistent fever and multiple organ dysfunction after a tick bite at a wetland park in Inner Mongolia. Next-generation sequencing in this patient revealed an infection with a previously unknown orthonairovirus, which we designated Wetland virus.”
The study has found that the Wetland virus can potentially reach the brain and lead to comas.
In the case of the 61-year-old man, he was given antibiotics which failed to ease his symptoms and it was at that point that medics realised it must have been a virus rather than a bacterial infection. Blood tests showed it was a previously unknown orthonairovirus - that has strains that are transmitted by ticks.
This was done through analysis of nearly 14,600 ticks with the Wetland virus found in five tick species.It was most often found in haemaphysalis concinna, a rodent tick species mainly present in China, Russia and central parts of Europe.
Experts in The New England Journal of Medicine said that the Wetland virus had not been found before in animals or humans. Researchers analysed healthy forest rangers who were working in the wetlands where the 61-year-old man had become ill and they discovered that 12 out of 640 carried antibodies against the virus.
The next step was to test for the virus in hospital patients who had been suffering from fevers after having a tick bite and 17 people were found to have the new virus and recovered. One person who went into a coma had a high white blood cell count in the fluid surrounding their brain and spinal cord showing their brain had an infection, and the virus generally caused tissue damage and blood clotting.
The presence of the new virus was also carried out among animals, while in lab mice the virus led to deadly infections that reached the brain. "Taken together, these data suggest that a newly discovered orthonairovirus, WELV, is [pathogenic] to humans … and circulates among humans, ticks and various animals in northeastern China," the researchers said.
