Local Numbers Have Shifted Over Time

By: Thalita Campelo, Regional Health Communications Specialist, MetroWest Shared Public Health Services

Tick-borne diseases pose a significant threat to public health in Massachusetts, with cases on the rise in recent years. Understanding the threat of ticks and how to prevent tick bites is crucial for protecting ourselves and our loved ones from these potential dangers, especially as the weather warms and outdoor activities begin to increase. 

Regional Tick Borne Disease Trends 

According to Regional Epidemiologist Pooja Shelke, “In the MetroWest region, Lyme disease continues to be the most common tick-borne illness, with reported cases increasing from just 1 case in 2021 to 185 in 2022 and peaking at 305 cases in 2023.” Anaplasmosis and babesiosis are also on the rise. For example, babesiosis cases more than doubled from 10 in 2021 to 23 in 2024, and anaplasmosis has grown from 11 cases in 2021 to 21 already in 2025. Pooja added, “We typically see the highest number of tick-borne disease reports during late spring through early fall, when people are spending more time outdoors. These trends remind us that prevention is critical.”

Prevalence of Tick Borne Disease in MA

The prevalence of these diseases is closely tied to the abundance of the black-legged tick population, which thrives in wooded and grassy areas, as well as suburban backyards. This makes outdoor activities such as hiking, camping, gardening, and even leisurely walks risky without proper precautions. 

“Ticks are most active in Massachusetts from early spring through late fall, which is why we see the highest number of tick-borne disease cases during this period.” Ticks thrive in wooded areas, tall grasses, brush, and even suburban backyards. Their life cycle and behavior align closely with when people spend more time outdoors, making late spring and summer especially high-risk seasons. “Of particular concern are nymph-stage ticks, which are small, hard to detect, and responsible for most tick-borne disease transmission.” 

Tick Identification and Symptoms

Massachusetts has three common tick species: black-legged ticks (also known as deer ticks), dog ticks, and lone star ticks. Deer ticks are brown with black legs and are about the size of a paperclip. They can spread Lyme disease, babesiosis, anaplasmosis and Powassan virus. The highest risk of being bitten by a deer tick is in the spring, summer, and fall. Dog ticks can be divided into two species: American dog ticks and brown dog ticks. Brown dog ticks are reddish-brown in color and are 1/8–3/16″ in length. The greatest risk of being bitten occurs during spring and summer. Lone star ticks are aggressive ticks that bite humans. The adult female is distinguished by a white dot or “lone star” on her back. Lone star ticks will occasionally develop a circular rash similar to the rash of early Lyme disease. The greatest risk of being bitten by the lone star tick during the year is in the early spring through late fall. 

The symptoms of Lyme disease can range from mild flu-like symptoms to severe joint pain and neurological complications if left untreated. Anaplasmosis can cause fever, headaches, and muscle aches, while babesiosis, caused by microscopic parasites that infect red blood cells, can lead to symptoms similar to malaria. Powassan virus, though rare, is particularly concerning due to its potential for severe neurological complications.

Prevention Works!

Prevention is the most effective way to minimize the risk of tick-borne diseases. Wearing long sleeves and pants, using insect repellents containing DEET or oil of lemon eucalyptus, and conducting thorough tick checks after outdoor activities are essential practices. 

Additionally, creating tick-safe zones around homes by clearing tall grasses and brush, and using tick control products can help reduce exposure. Early detection and prompt treatment are crucial in managing tick-borne illnesses. If you suspect you’ve been bitten by a tick or are experiencing symptoms associated with these diseases, it’s imperative to seek medical attention promptly. 

By adopting preventive measures, staying informed, and seeking timely medical care, individuals can enjoy the outdoors safely while minimizing the threat posed by ticks. For more information visit cdc.gov/ticks or the Massachusetts Department of Public Health.