On May 23, 2022, a study reports the economic burden of Lyme disease could be nearly $1 billion annually, according researchers from the Yale School of Public Health, the U.S. Centers for Disease Control and Prevention (CDC), and health officials from four states heavily impacted by the disease.

The report, the CDC’s most comprehensive evaluation of the economic impact of Lyme disease to date, looked at the total cost of diagnosed Lyme disease cases between September 2014 and January 2016 and followed reported cases in four states where the tickborne disease is prevalent: Connecticut, Maryland, Minnesota, and New York.

“Lyme disease represents a substantial economic burden to individuals and U.S. society,” said Sara Niesobecki, one of the study’s co-authors and an investigator with the Connecticut Emerging Infections Program (EIP) at the Yale School of Public Health. “The aggregate cost of diagnosed Lyme disease could be close to $1 billion annually but this does not include suspected, undiagnosed, or nonacute cases.”

In estimating the economic burden of Lyme disease, the researchers collected data for direct medical costs, nonmedical costs, and losses in productivity from patients clinically diagnosed with Lyme disease. They also collected billing code information from the patients’ health care providers to assess societal costs (i.e., all costs, no matter who pays them, whether the patient, health care system, third party payer/insurance, or government) and patient costs (i.e., “out-of-pocket” costs). They determined that the average out-of-pocket patient cost was approximately $1,200 per illness and the average societal cost was about $2,000 per patient.

Using these data and additional information on the estimated number of Lyme disease cases diagnosed in the United States, the researchers estimated that the annual total cost of diagnosed Lyme disease could be $345 million to $968 million (in 2016 U.S. dollars).Patients with later stages of disease had double the costs of those with early disease.

Lyme disease is the most common vector-borne disease in the United States, and approximately 476,000 cases of Lyme disease are diagnosed and treated each year nationally. Lyme disease is caused by the bacterium Borrelia burgdorferi and rarely, B. mayonii, which is transmitted to people through the bite of an infected blacklegged tick. Early symptoms can include rash and flu-like symptoms. If untreated, later signs and symptoms can include facial palsy, arthritis, nerve pain, and heart palpitations or an irregular heartbeat.

The study estimating the economic burden of Lyme disease was published in Emerging Infectious Diseases.