Lyme Disease Statistics

Tick on grass.

The Connecticut Department of Public Health (CTDPH) has maintained one of the most comprehensive Lyme disease surveillance systems in the country since 1987. To define the epidemiology of Lyme disease in Connecticut and follow disease trends, surveillance methods were modified and enhanced over time as surveillance goals and resources changed. Surveillance has included passive and active methods that incorporated physician-reporting (1987-present) and laboratory-reporting (1998-2002, 2006-present) components. These data reflect cases meeting the national surveillance case definition for monitoring purposes. Since Lyme disease may be suspected based on broader clinical criteria, these data do not reflect all persons diagnosed or treated.


Understanding Lyme disease Surveillance (CDC)


National Lyme disease Surveillance Case Definition (CDC)



Annual Cases and Rates by Town and County


All reports are in PDF.


2017          2016


2015          2014          2013          2012          2011         


2010          2009          2008          2007          2006


2005          2004          2003          2002          2001


2000          1999          1998          1997          1996


1995          1994          1993          1992          1991