John Elflein
Research expert covering health and health care
Lyme disease in the U.S. - Statistics & Facts
Lyme disease is caused by bacteria that are transmitted to humans through the bite of infected ticks. Although other diseases can also be transmitted through ticks, Lyme disease is by far the most prevalent tick-borne disease in the United States and is in fact the most common vector-borne disease in the country. Initial symptoms of Lyme disease are similar to that of the flu, making it difficult to diagnose, and include fever, headache, fatigue, and body aches. Lyme disease can be treated and cured with antibiotics if it is diagnosed early enough, but, if left untreated, symptoms can become more severe and can affect the heart, joints, brain and spinal cord. Lyme disease funding from the National Institutes for Health (NIH) has increased in recent years and reached a high of 50 million U.S. dollars in 2022, but dropped to 43 million U.S. dollars in 2023.
How many cases of Lyme disease are there every year?
The annual number of Lyme disease cases in the United States fluctuates, but has generally increased over the past couple decades. In fact, 2022 saw the highest number of Lyme disease cases ever recorded in the U.S. with over 62 thousand cases. In comparison, in 2021 there were around 24,600 confirmed cases of Lyme disease. In 2022, the incidence rate of Lyme disease was 18.83 per 100,000 population, the highest rate over the last 26 years. The second highest incidence rate over that period was recorded in 2017 with 13.15 new Lyme disease cases per 100,000 population. Rates of Lyme disease in the U.S. are higher among males than females and the disease is more common among young children and older adults. In the period 2008 to 2022, men aged 65 to 74 years had the highest rates of Lyme disease in the country.When and where is Lyme disease most prevalent?
As Lyme disease is passed onto humans through ticks, there are large regional differences in Lyme disease incidence rates depending on the pervasiveness of ticks. States in the northeast of the United States experience the highest incidence rates of Lyme disease because these areas are host to the largest number of infected ticks. In 2022, the states with the highest incidence rates of Lyme disease were Rhode Island, Vermont, and Maine. Similarly, there are seasonal differences in Lyme disease cases. Unsurprisingly, the months around when ticks are most active are the ones in which the highest number of new Lyme disease cases occur, with June and July accounting for the largest portion of new cases. Preventing Lyme disease rests on avoiding tick bites, with the most common preventative measures including wearing clothing to cover ankles, using insect repellant, and avoiding areas with deer.
