Date of Award

January 2023

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

James Hadler


Introduction: Shiga-toxin producing Escherichia coli (STEC) is a common foodborne pathogen known to cause significant gastrointestinal illness in humans and often results after contact with animals and/or consumption of food that has been contaminated. STEC is a major contributor of foodborne outbreaks in the US. Understanding major contributors of infection is important to improving prevention. Methods: Cases of STEC reported in routine Connecticut FoodNet surveillance were included. Trends in demographic features, serotypes, and exposure histories were used to assess whether there was variation among cases between 2017 and 2021, and pre (2017-2019) and post (2020-2021) COVID-19 pandemic. CT respondents of the 2018-2019 FoodNet Population Survey were used as healthy controls to conduct a case-control analysis, examining the odds of self-reported exposure to known risk factors in cases versus controls. Results: From January 1, 2017 to December 31, 2021, there were 508 cases of STEC in CT. The number of cases varied over time, with 2018 containing the greatest number of cases (n=132) and 2020 the fewest (n=77). Cases of STEC varied significantly by race/ethnicity, age, reported travel, HUS-causing infections, and serotype. Incidence varied over time by race/ethnicity, sex, and age. Individuals that identified as Hispanic/Latino experienced the greatest difference, with an incidence rate of 0.16/100,000 in 2017 increasing yearly to 5.57/100,000 in 2021. Reported exposure also varied by year and pre- versus post-COVID-19 pandemic. Notably, ground beef consumption varied significantly, from 38.2% pre-COVID-19 to 52.2% post-COVID-19. Discussion: STEC infections in Connecticut varied significantly during 2017-2021, in terms of the demographics of cases and their reported exposure histories. These notable differences are useful in evaluating the success of current prevention interventions in CT and can help inform new methods to further prevent infection across the state.


This is an Open Access Thesis.

Open Access

This Article is Open Access