Babesiosis: A Tick-Borne Illness on the Rise

You might be familiar with Lyme disease, an infection caused by bacteria transmitted through the bite of an infected tick. While Lyme disease is the most commonly reported tick-borne illness in the United States, there is another disease that is increasing in prevalence: babesiosis. According to a CDC report from March 2023, babesiosis has now established itself in 10 states in the Northeast and Midwest regions.

What is babesiosis?

Babesiosis is an illness caused by a parasite called Babesia microti, which invades and infects red blood cells. It is transmitted through the bite of infected black-legged ticks, commonly known as deer ticks. Typically, the tick needs to remain attached to a person for at least 36 hours to transmit the parasite.

What are the signs and symptoms of babesiosis?

You may or may not notice the tick bite mark on your skin, so your symptoms could be the earliest indication of an infection.

While some individuals with babesiosis may not experience any symptoms, the most common signs include a combination of:

• Severe flu-like symptoms such as a high fever (up to 104°F), chills, and night sweats.
• General discomfort or feeling unwell.
• Intense headaches.
• Muscle and joint pain.
• Loss of appetite.
• Nausea.
• Fatigue.

These symptoms can manifest within one to nine weeks or even several months after the initial infection. In some cases, babesiosis can cause a type of anemia called hemolytic anemia, where red blood cells are destroyed faster than they can be replaced. Signs and symptoms of this form of anemia include fatigue, dizziness, weakness, dark urine, and yellowing of the skin and whites of the eyes.