Scientists in China have identified a previously unknown tick-borne virus that can cause a flu-like illness. The virus, called Asian longhorned tick nairovirus (ALTNV), was identified in patients who had been bitten by ticks and developed symptoms including fever, fatigue and gastrointestinal problems.
The discovery, published in the New England Journal of Medicine, is another reminder of how much scientists continue to learn about the viruses and other germs that ticks can carry.
What Is ALTNV?
ALTNV is a newly identified virus in the orthonairovirus group. Researchers discovered it while investigating patients in China who had been bitten by ticks and developed fever and other symptoms but who were negative for all currently known viruses.
The researchers tested 3,163 patients and found evidence of ALTNV infection in about 10 percent of them. Among the patients who had ALTNV alone, the most common symptoms included fatigue, digestive problems, fever and low platelet counts, also known as thrombocytopenia. All 56 patients with ALTNV alone recovered.
Some patients were infected with both ALTNV and Dabie bandavirus (DBV), the virus that causes severe fever with thrombocytopenia syndrome, or SFTS (an illness unique to China). Seven of the 38 patients with both infections died. The researchers found that people with both viruses tended to have more severe illness than those infected with ALTNV alone.
What Is SFTS?
Severe fever with thrombocytopenia syndrome, or SFTS, is a serious illness caused by Dabie bandavirus. This illness is not associated with any other ticks except the Asian Long Horned tick. This illness is only found in China. The name describes two of its main features: a high fever and a low platelet count. Platelets are blood cells that help the body form clots.
SFTS can cause serious complications and can be fatal. Reported fatality rates in areas where the disease occurs have been about 10 percent to 30 percent. Importantly, that mortality rate refers to SFTS caused by Dabie bandavirus, not ALTNV alone.
In the new study, all patients who had ALTNV alone recovered. The deaths occurred among patients who were infected with both ALTNV and Dabie bandavirus.
What Does This Mean for the United States?
There is currently no evidence that ALTNV is causing human illness in the United States. The virus was identified in patients in China. This is important information for travelers, those going to China and those returning from trips to China. Please inform your medical provider of your itinerary as these details will help them to deliver the best care to you.
However, the tick associated with ALTNV, the Asian longhorned tick (Haemaphysalis longicornis), is already present in parts of the United States, including New York. The presence of the tick does not mean that ALTNV is circulating here.
The United States has many other tick-borne diseases to be aware of. In New York, these include:
- Lyme Disease
- Anaplasmosis
- Ehrlichiosis
- Babesiosis
- Rocky Mountain Spotted Fever
- Bourbon Virus
- STARI
- Alpha-Gal Syndrome
Ticks Carry Many Different Germs
One important takeaway from this discovery is that ticks can carry many different viruses, bacteria and parasites, and scientists continue to improve their ability to identify them.
Many tick-borne illnesses can cause similar symptoms, such as fever, fatigue, headache and muscle aches. Understanding which infections are present in a particular region, along with a person’s history of tick exposure, can help healthcare providers determine what testing and treatment may be appropriate.
How to Protect Yourself From Tick Bites
The best way to prevent tick-borne illness is to prevent tick bites.
When spending time outdoors:
- Use tick repellent. Follow the product directions and choose a repellent appropriate for your age and activity.
- Cover up. Wear long pants and consider tucking pants into socks when walking through areas where ticks may be present.
- Check for ticks. Check yourself and your children after spending time outdoors. Look carefully around the scalp and hairline, behind the ears and knees, around the waist and in other areas where ticks can hide.
- Check pets, too. Dogs and other pets can carry ticks into the home.
- Remove ticks promptly. If you find an attached tick, remove it as soon as possible with fine-tipped tweezers.
If you develop a fever, unusual fatigue, rash or other symptoms after a tick bite or spending time in an area where ticks are common, contact your healthcare provider. Many tick-borne illnesses can look similar to one another in the early stages, so your symptoms and recent exposure are important information for your physician.
The Bottom Line
The discovery of ALTNV does not mean this virus is circulating in the United States. It does show that scientists are continuing to discover new germs carried by ticks and improve the ways they identify them.
For families, the advice remains simple: prevent tick bites, check for ticks after spending time outdoors and remove attached ticks promptly.
