Infectious Diseases Statistics



As part of the core public health functions, disease data are collected and maintained by the Infectious Diseases Division of the Connecticut Department of Public Health (DPH). It is important to note that surveillance methods may change over time as needed to reflect how the data will be used. These changes can have an impact on the number of cases and incidence of disease over time. The Infectious Diseases Section monitors over 80 reportable diseases, emergency illnesses, and health conditions that are declared reportable by the Commissioner of the DPH. Surveillance is conducted for many infectious diseases including, for example, vector-borne, foodborne, healthcare associated, vaccine preventable, and sexually transmitted illnesses, as  well as, HIV, viral hepatitis, and tuberculosis. Collected data are used by the DPH to identify trends, outbreaks, and changes in infectious agents. Aggregate data of reportable diseases over time, can be found below. All documents are in PDF. For other data needs, please contact the appropriate program listed below.

Number of reportable disease cases by county, by year                   

2018                    2017                    2016                                       

2015                    2014                    2013                    2012                    2011

2010                    2009                    2008                    2007                    2006


Number of reportable disease cases by year

2000-2005                     1990-1999                    1980-1989


Statistics by disease


Healthcare Associated Infections

Hepatitis B

Hepatitis C



Lyme disease




West Nile virus

Zika Virus infection


Outbreak Information 

Information on foodborne outbreaks in Connecticut is available through the National Outbreak Reporting System (NORS).

Illness Information

Information on Foodborne Pathogens Active Surveillance Network (FoodNet) is available through FoodNet Fast.

Both databases are maintained by the Centers for Disease Control and Prevention (CDC) and allow you to search by several different variables.

Infectious Disease Programs and Phone Numbers

Epidemiology and Emerging Infections  860-509-7994

Healthcare Associated Infections  860-509-7995

HIV Surveillance  860-509-7900

Immunizations  860-509-7929

Sexually Transmitted Diseases  860-509-7920

TB, HIV, STD and Viral Hepatitis  860-509-7801

Tuberculosis  860-509-7722


For national public health data, please visit the Centers for Disease Control and Prevention website.



This page last updated 1/24/2020.