Babesiosis: Why the CDC says this rare tick-borne disease is now endemic across New England

Photo provided by the U.S. Centers for Disease Control and Prevention shows a blacklegged tick, also known as a deer tick, a carrier of Lyme disease. (CDC via AP)
Photo provided by the U.S. Centers for Disease Control and Prevention shows a blacklegged tick, also known as a deer tick, a carrier of Lyme disease. (CDC via AP)

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The coveted return of warm weather in New England means many things: longer days, blooming flowers and, unfortunately, ticks.

After yet another mild winter, experts say a rare tick-borne disease is on the rise. Babesiosis — a malaria-type disease that was first found in the U.S. over 50 years ago on Nantucket — is now endemic to all six states in New England. Here’s what to know:

Late last week, the CDC published its first comprehensive survey on babesiosis, finding a 25% increase in nationwide cases from 2011 to 2019. NPR reports that babesiosis is now considered endemic in all of northern New England, in addition to Massachusetts, New Jersey, New York, Connecticut and Rhode Island (where it already was endemic). The disease is carried by deer ticks, which have become more active in the region due to warming winters.

  • Babesiosis does remain pretty rare. States reported around 1,800 cases a year between 2011 and 2019 — a fraction of the 30,000 Lyme disease reports the CDC says it receives annually.
  • While some babesiosis cases are asymptomatic, about 80% of infections lead to symptoms like fever, chills and muscle pain, according to Edouard Vannier, a babesiosis expert at Tufts Medical Center. Extreme cases can be life-threatening, particularly for those who are immunocompromised or elderly.
  • Why is it on the rise? Vannier told WBUR’s Irina Matchavariani there’s multiple factors. But like Lyme disease, Vannier says the spread is accelerated by warmer temperatures. “So, there is possibly an impact of climate change on this spread northward,” he told Matchavariani. (Previous theories also noted a relation to the return of white-tailed deer.)
  • What’s next: Vannier says there have already been babesiosis cases as far north as the Canadian border and “we can expect reasonably” that cases will only continue to rise in the coming years.
  • How to avoid it: Well, the best way to avoid tick-borne diseases is to avoid ticks. Here’s a timeless guide to avoid getting bitten.

Get ready for another Massachusetts springtime staple: construction. Starting tonight through October, state officials will implement overnight “rolling roadblocks” and lane closures on the stretch of the Mass. Pike behind Fenway Park in both directions.

Bay State College will officially be stripped of its accreditation this August, after losing its appeal yesterday to the New England Commission of Higher Education. WBUR’s Max Larkin reports that the decision is a final blow to the tiny, for-profit Back Bay school’s hopes of staying open.

  • Bay State College is calling the NECHE’s final ruling “flawed,” but says they accept the decision. As they wind down operations this summer, college leaders say they will work to ensure that eligible students graduate this spring and help those who aren’t graduating transfer to other colleges. Read more from Larkin here.
  • In more uplifting college news: Tom Hanks will be Harvard’s 2023 commencement speaker. We can only assume he’ll urge graduates to “reach for the sky.”

The first mother and baby Right Whale pair of the season have been spotted in Cape Cod Bay. Stormy Mayo, a co-founder of the Center for Coastal Studies, tells WBUR’s Amy Sokolow that the sighting is an important event because it indicates the calf has survived a “long and rather dangerous trip up the East Coast” from Georgia.

P.S.— The Harvard Kennedy School is hosting a free, public screening tomorrow night of “The Territory.” The award-winning documentary provides an immersive, on-the-ground look at the indigenous fight against deforestation in the Brazilian Amazon. WBUR’s own Paula Moura, who worked on the film as a field producer, will also be there for a Q&A after the screening. (There’ll be food, too.) Register here.


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Nik DeCosta-Klipa Newsletter Editor
Nik DeCosta-Klipa is the newsletter editor for WBUR.



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