Data and Surveillance

Possible cases of Lyme disease are reported to state and local health departments by health care providers and laboratories. State health departments classify cases according to standard criteria outlined in the Lyme disease case definition and report confirmed and probable cases to CDC. The extent of case investigations varies by state. Investigations are often dependent on available resources and staff time. Some states describe their surveillance methods in detail on their health department website.

Each year, approximately 30,000 cases of Lyme disease are reported to CDC by state health departments and the District of Columbia. However, this number does not reflect every case of Lyme disease that is diagnosed in the United States every year. Standard national surveillance is only one way that public health officials can track where a disease is occurring and with what frequency. Recent estimates using other methods suggest that approximately 476,000 people may get Lyme disease each year in the United States.