Babesiosis: The Tick-Borne Disease on the Rise

As spring brings more people outdoors, the risk of tick bites and tick-borne diseases also increase. Blacklegged ticks, which are common in the Northeast and most active during the spring through the end of the summer, are usually associated with Lyme disease. But another disease carried by the tick, babesiosis, is on the rise and has more than doubled in some Northeastern states between 2011 and 2019, according to a recent study by the Centers for Disease Control and Prevention (CDC).

Dr. Sorana Segal-Maurer, director of the Dr. James J. Rahal, Jr. Division of Infectious Diseases at NewYork-Presbyterian Queens, spoke to Health Matters about babesiosis and how to keep yourself, your loved ones, and your pets tick-free when enjoying time outdoors.

What is babesiosis?
Babesiosis is a parasitic disease carried by blacklegged ticks, also known as deer ticks, that infects a person’s red blood cells. Most people who contract this disease will be asymptomatic, while others will feel terrible. But people who are immunocompromised or who have had a splenectomy – the removal of the spleen, which filters parasites from your blood system – are at risk for severe illness or possibly death.

Is this disease new?
No. The disease has been circulating for decades. What’s new is the increase in cases in the Northeast. According to the CDC, cases of babesiosis rose significantly in recent years in Connecticut, Massachusetts, New Jersey, New York, Rhode Island, Maine, New Hampshire, and Vermont. In New York State, the percentage of ticks found to carry babesiosis grew from 6.5% in 2020 to nearly 15% in 2021, according to researchers at State University of New York Upstate Medical University.

Despite the increase in cases, babesiosis is still quite rare. In 2020, the last year data is available, there were 464 confirmed cases of babesiosis in New York State, compared to 4,830 cases of Lyme disease.

What are the signs and symptoms of babesiosis?
The typical signs are fever, muscle pain or stiffness, fatigue, and jaundice. Some of these signs can be similar to Lyme disease, but the incubation period for babesiosis is lengthy so a person might not experience any of these symptoms anywhere from one to nine weeks after being exposed to a tick. Symptoms of Lyme usually occur within three to 30 days after a tick bite.

How is it treated?
If a person is asymptomatic, they won’t need to be treated. If someone develops symptoms weeks after being bitten by a tick and blood tests confirm the presence of babesiosis, they would be put on a regimen of antimicrobial drugs for 7 to 10 days, depending on the severity of the illness.

Can you get both Lyme disease and babesiosis from the same tick?
Yes. Blacklegged ticks can carry four diseases: Lyme disease, anaplasmosis, babesiosis, and Powassan virus. And they can carry all four at the same time, so if you are exposed to a tick that carries one or all of these diseases, you are at risk of acquiring one or more diseases.

Can you treat Lyme and babesiosis with the same medication?
No. The antibiotic treatment for Lyme will not treat babesiosis. It will treat anaplasmosis, so if you are treated for Lyme and you happen to also have anaplasmosis and you are prescribed doxycycline, you are effectively treated for both. Lyme disease presents much sooner than babesiosis, so a person who feels sick days or a few weeks after being bitten by a tick likely has Lyme. Affected persons should be counseled that if they experience new symptoms weeks after being treated for Lyme, they should seek medical care immediately to get tested for babesiosis and, if necessary, begin treatment.

How can I prevent babesiosis?
The same precautions you would take to avoid tick bites in general is the best way to prevent babesiosis. Wear light-colored clothing so ticks are easier to see, and socks over pants and long-sleeved shirts to prevent ticks from getting near your skin. And don’t forget hats.

Applying a tick repellent with a concentration of DEET of up to 30% or with eucalyptus oil has proven effective, as has pretreatment of clothing with permethrin. But you have to be careful about its use around cats. If you treat dogs with permethrin, cats need to be kept away from them.

When you’re outside, stay on paths. Once you brush against foliage, you’re putting yourself at risk.

What should you do if you’ve been in an area with ticks?
After you’ve gone camping or hiking or spent time gardening or mowing the lawn, check for ticks in your hair, around your groin, your underarms, and behind your knees. If you were in a tick area with kids, put their clothes in the washer and dryer to kill any ticks before performing a tick check. Perform a tick check on any pets, too, if they’ve explored areas where ticks are prevalent, like leaf piles or plant overgrowth.

If you find a tick on your body, should you remove it? What is the best way to do it?
Once they attach, they can be difficult to pull out. There are a number of talked-about remedies that do not work and can be dangerous, like using petroleum jelly to “smother the tick” or “burning it off,” which just serves to cause a nasty burn. There’s really no way of doing it other than making sure you have a very sharp pair of tweezers. Not blunt tweezers, because if you squeeze the tick, you increase the potential to infect yourself. Try to pull it out from the mouth straight out, not twisting. That’s very important.

When you’re disposing of it, either flush it down the toilet or drop it in rubbing alcohol in case you end up with a rash and want to bring it in for identification.

After removing the tick, what are the next steps?
Call your healthcare provider. If it’s been attached for more than 24 to 48 hours and you can reasonably see it is engorged and larger than the size of a poppy seed or grain of sand, it has probably fed, increasing your risk for a tick-borne disease.

You can also reach a provider using telehealth. If you think you’ve been bitten by a tick, you can consult with doctor via a video visit, show the doctor your rash, or even show them the tick, and they can put you on a doxycycline preventive regimen and call it in to your pharmacy, all without your having to go to a doctor’s office.

Anything else people should be aware of?
If you are bitten by a tick, be vigilant about seeking medical care if you begin to feel sick in the days or weeks after your exposure. And make sure your healthcare provider looks for all the infections that we see with these tick-borne illnesses.

Sorana Segal-Maurer, M.D., is director of the Dr. James J. Rahal, Jr. Division of Infectious Diseases at NewYork-Presbyterian Queens and a professor of clinical medicine at Weill Cornell Medicine.