A NEW tick-borne virus that can trigger deadly brain infections has been discovered in humans for the first time.
The bug, dubbed wetland virus (WELV), was first detected in a hospital patient who was treated in the city of Jinzhou, in China, in June 2019, according to a new report.
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Investigations have since revealed that the virus, carried by ticks, can potentially reach the brain and induce comas.
The 61-year-old mentioned in the report developed fever, headache, and vomiting five days after visiting a park in Inner Mongolia’s large wetland.
He told doctors he’d been bitten by ticks at the park and was prescribed antibiotics.
When the drugs failed to ease his symptoms, medics realised the man was suffering from a viral infection rather than a bacterial one.
Blood tests identified a previously unknown orthonairovirus, a group of related viruses that includes several transmitted by ticks.
Crimean-Congo hemorrhagic fever is a rare but better-known orthonairovirus, which kills a third of those it infects.
Writing in The New England Journal of Medicine, the experts said WELV had not been found in animals or humans before.
After uncovering the virus in the hospital patient’s blood, the researchers went searching for it in ticks and animals in northern China.
They found that five different tick species could carry the virus, but the Haemaphysalis concinna tick, which is mainly found in Russia and Eastern Europe, came up positive the most often.
The team also analysed blood from ‘healthy’ forest rangers who worked in Mongolia’s wetland and found that 12 out of 640 carried antibodies against the virus.
They went on to test for the virus in hundreds of hospital patients who had developed fevers within one month of a known tick bite, and 20 tested positive for the new bug.
They found that people with WELV infections experience common symptoms like fever, dizziness, headache, malaise, back pain, nausea, vomiting, and diarrhoea.
Lab results also revealed people can suffer from tissue damage and blood clotting issues.
One WELV-infected patient slipped into a coma and showed a high level of white blood cells around the brain and spinal cord, a clear indicator of severe infection.
‘IMPROVED SURVEILLANCE NEEDED’
However, with treatment, all patients recovered and were discharged within four to 15 days, according to the researchers.
When the experts injected the virus into lab mice, they discovered it could cause severe, often fatal infections, affecting multiple organs, including 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 concluded.
“Improving surveillance and detection for emerging orthonairoviruses will allow a better understanding of the effect that these viruses have on human health.”
How dangerous are ticks?
By Isabel Shaw, health reporter
Ticks might be small, but they pack a big punch when it comes to health risks.
The tiny critters can harbour nasty diseases that affect both humans and animals.
From Lyme disease to tick-borne encephalitis (TBE) the list of tick illnesses is extensive and can lead to serious long-term issues if not caught early.
The bloodsucking nats often latch onto their hosts while they’re out in the wild searching for their next meal.
It’s worth bearing in mind that most ticks – especially those found in the UK – don’t pass on diseases to humans. But it always pays to be cautious.
Ticks are most active in England from April to July but can be active all year round.
It’s important to check for ticks after spending time in grassy or wooded areas and to take preventive measures to avoid their bites.
To protect yourself from ticks, you can:
- Wear protective clothing like long-sleeved shirts, long pants, and socks or boots that are tucked in. Light-colored clothing can help you spot ticks
- Use insect repellent on exposed skin, such as your legs and hands. You can also treat your clothing and gear with permethrin-containing insecticide
- Avoid tick-prone area like wooded or brushy areas with high grass and leaf litter. When walking, keep to footpaths and avoid long grass
- Check for ticks, this includes areas like under the arms, behind the knees, and in the hair
- Shower after being outdoors
- Check your pets and make sure they don’t bring them into your home
