What is Babesiosis? The tick-borne disease rising in 8 states: NPR

A rare tick-borne disease is on the rise in the northeastern United States, according to a new report from the Centers for Disease Control and Prevention.

Cases of babesiosis rose 25% from 2011 to 2019, prompting the CDC to add three states — Vermont, Maine, and New Hampshire — to the list of states where the disease is considered endemic.

Here’s what you need to know.

What is babesiosis and how do I know if I have it?

Babesiosis is caused by the Babesia parasite — a type of protozoan that infects red blood cells — that can be carried by black-legged ticks (also known as deer ticks) in the northeastern and midwestern United States.

A bite from a tick carrying the parasite can send it into a person’s bloodstream.

Some cases are completely asymptomatic, but others are accompanied by fever, muscle headache, myalgia, joint pain and other symptoms. A doctor can prescribe antimicrobial medications to help fight infection.

In the most extreme cases, babesiosis can be fatal, especially among those who are immunocompromised, the CDC says. The disease can also be associated with life-threatening complications, including low platelet counts, kidney failure, or respiratory distress syndrome.

Although cases of babesiosis are on the rise, the disease is still relatively rare, with states reporting more than 1,800 cases of babesiosis per year to the CDC between 2011 and 2019. Compare that to the most common tick-borne disease, Lyme disease: The CDC says it receives 30,000 reports of Lyme cases each year.

For both diseases, the true number of cases is likely much higher, the CDC says, because data is reported state by state and procedures vary. For example, ten states do not require notification of babesiosis at all.

Where is it spreading?

Of the states that do require reporting, eight saw significant increases in cases between 2011 and 2019, according to the CDC’s first comprehensive national surveillance of babesiosis.

In three states — Vermont, Maine and New Hampshire — cases increased so much that the CDC says babesiosis should be considered endemic.

Increases were also seen in states where the disease was already endemic: Massachusetts, New Jersey, New York, Connecticut and Rhode Island.

The CDC did not give an explicit reason for the rise in babesiosis cases, but state programs that track cases of tick-borne diseases have said milder winters may be to blame for rising infection rates, as they allow ticks to remain active year-round .

In the long term, an extension of babesiosis can affect blood supply, the CDC says. The agency says the parasite can be transmitted through a blood transfusion and those who contract the disease through contaminated blood have “significantly poorer health outcomes.”

The Food and Drug Administration already recommends screening for the parasite at blood donation centers in the 14 states with the most cases, as well as Washington, D.C.

What can I do to avoid contracting babesiosis?

In general, the best way to do the Babesia parasite is to avoid black-legged ticks. That is, avoid encounters with ticks altogether.

Babesia is usually dispersed by young nymphs, which can be as small as a poppy seed.

Are you planning to venture into the woods or brush in these warmer spring and summer months? Bobbi Pritt, a parasitologist at the Mayo Clinic, told NPR’s Sheila Eldred some of her top tips for avoiding tick bites:

1. Wear long sleeves and long pants, even tucking your cuffs into your socks if there is a gap.
2. Spray exposed skin with insect repellent.
3. Take off your clothes before going back inside.
4. Toss those clothes in the dryer on high heat for a few minutes to destroy any stragglers.
5. And don’t forget to check your pets and children.

And if you do get bitten, stay calm. Not every tick carries harmful bacteria.

But it also doesn’t hurt to check whether your tick has black legs. If so, Pratt recommends sticking it in your freezer so you can take it to the doctor in case any symptoms appear.