Lyme Disease


Black-legged (Deer) Tick

Lyme disease is caused by the bacterium Borrelia burgdorferi. In Connecticut it is spread to people through the bite of an infected Black-legged (“deer”) tick (Ixodes scapularis). It is the most commonly reported tick-borne disease in Connecticut and in the United States. Treatment is available. The best way to prevent Lyme disease is to prevent tick bites.


About Lyme Disease


Post-Treatment Lyme Disease Syndrome

Protect Your Pet

Connecticut's Lyme disease history 

Information for Clinicians


Clinical Guidance (CDC)

National Surveillance Case Definition


Connecticut Provider Reporting Information

Reportable Disease Confidential Case Report, PD-23

Connecticut Laboratory Reporting Information

              Reportable Laboratory Findings form OL-15C


Directory of Clinical Testing Services provided by the State Public Health Laboratory

State Public Health Laboratory Contacts – for additional information


Tick-borne Diseases of the United States – a Reference Manual for Healthcare Providers


Connecticut Lyme Disease Surveillance


The Connecticut Department of Public Health (DPH) added Lyme disease to the list of state-wide reportable diseases in 1987. DPH uses the Centers for Disease Control and Prevention surveillance case definition, which was first established in 1995, and last updated in 2017. Since 1995, an average of 2,718 cases (range 1,348 to 4,631) have been reported to the DPH annually. Surveillance for Lyme disease currently includes physician and laboratory reporting. Due to the delay in follow-up, current case counts do not represent all cases of Lyme disease.

Cases of Lyme disease reported to the DPH from January 1 – December 31, 2019.

Total Cases = 1,175 (738 Confirmed & 437 Probable)


Connecticut Annual Lyme Disease Statistics

Connecticut Annual Infectious Diseases Statistics




This page last updated 1/14/2020.