Date of Award

January 2014

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

James Hadler


Background: Previous studies in Connecticut (CT) have shown an association between higher incidence of bacterial foodborne pathogens, including Salmonella, Campylobacter, and shiga-toxin producing E. coli. Two hypotheses have been proposed to explain this association: 1) individuals of higher SES are more likely to seek medical care and be diagnosed following an episode of diarrhea or 2) the prevalence of risk factors for bacterial foodborne pathogens is higher among those of higher SES. CT is positioned to examine these two hypotheses because the FoodNet population survey, a source of data on SES, prevalence of healthcare-seeking behavior specific to diarrhea and prevalence of risk factors for foodborne illness, was conducted here.

Methods: Using the 2006-2007FoodNet population survey, we had two sources of SES data:-household income level, as reported by each participant in the survey, and ZIP code tabulation area (ZCTA)-level poverty, which was determined from each participant's ZIP code and the 2000 Census. Household income level was broken down into four categories: <$25,000 per year, $25,000 to <$55,000, $55,000 to <$100,000, and ≥100,000. ZCTA-level poverty was broken down into four categories: <5%, 5% to <10%, 10% to <20% and ≥20% of residents living below the federal poverty level. The age and sex-adjusted prevalences of exposure to selected risk factors for bacterial foodborne pathogens in the preceding seven days and of seeking care for diarrhea were determined for each SES level in each category. Trends from lowest to highest SES levels in each category were examined using the chi-square test for trend.

Results: A total of 1237 CT residents over the age of 18 years were included in the analysis. After adjustment for age and sex, 10 risk factors were associated with increasing SES, including 5 for household and 8 for ZCTA SES, and 4 risk factors were associated with decreasing SES, including 2 for household and 2 for ZCTA SES. Among 210 persons with diarrhea, there was a paradoxical finding for phoning a doctor, with it being associated with higher SES by household income and lower SES by ZCTA-level poverty. Despite this there were no significant differences in visiting a doctor. The correlation of household income with ZCTA poverty categories was low (r=0.25)

Conclusions: We found 1) no clear association between visiting a physician for diarrhea and SES status; 2) a number of risk factors for sporadic illness and outbreaks were more common among those of higher area-based SES status than those of lower area-based SES status and few risk factors were more common among those of lower area-based SES status; 3) results from using area-based and individual SES were not always concordant. These findings have implications for control of foodborne bacterial pathogens and for surveillance both of foodborne pathogens and for prevalence of risk factors for them.


This is an Open Access Thesis.