Date of Award

January 2022

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Linda Niccolai


Background: Recurrent Clostridioides difficile infection (CDI) is a cause of increased burden on the healthcare system and factors associated with this disease merit understanding. This study aimed to determine the incidence rate and to describe the factors associated with recurrent CDI cases in New Haven County from 2015 to 2020. It also examined the trends in annual recurrent CDI cases across epidemiological classes. Methods: This study utilized data from a population-based surveillance program of the Healthcare-Associated Infectious Community Interface (HAIC) Program within the Connecticut Emerging Infectious Program (CT EIP) at Yale School of Public Health which served all residents of New Haven County. Annual incidence rates of CDI and recurrent CDI in aggregate and by epidemiological class were calculated. Logistic regression analysis was carried out to determine factors associated with recurrent CDI. Results: Among 7,023 CDI cases from 2015-2020, the incidence rate of CDI in 2015 and 2020 was 165.2 and 107.8 per 100,000 persons respectively (median=140.2/100,000 persons; IQR=25.6/100,000 persons). Overall, 12% of 4,301 CDI cases with complete chart reviews had recurrent CDI, which made up 13.6% of all HCFO-CDI, 14.1% of all CO-HCFA CDI, and 10.5% of all CA-CDI. Specifically, 18.1 and 16.9 per 100 persons in 2015 and 2020 respectively had recurrent CDI (median=11.3/100 persons; IQR=4.7/100 persons). There were a 37.3% and 2.3% increase in recurrent CDI among HCFO and CA cases respectively from 2019 to 2020. A significant proportion of those who had recurrent CDI were older (median age=70.0 years, IQR=23.0 years; median age of non-recurrent group=64.0 years, IQR=26.0 years, p<0.001), female (recurrent of 66.0% vs non-recurrent of 61.3% p<0.039), White race, non-Hispanic, and had healthcare-associated incident CDI. In the final multivariable model, there was a higher risk of recurrent CDI among individuals who had malignancies (OR, 1.51; 95% CI, 1.11-2.07), used nitrofurantoin (OR, 2.37; 95% CI, 1.23-4.58), or were of White race. Also, cases with incident CDI in 2017 (OR, 0.43; 95% CI, 0.26-0.73), 2018 (OR, 0.60; 95% CI, 0.37-0.97), and 2019 (OR, 0.50; 95% CI, 0.30-0.84) had lower risk of recurrent CDI when compared with incident CDI cases in 2015. Conclusions: There was a lowered risk of recurrent CDI over time (from 2015-2019) which may reflect effective measures in management of CDI. The loss of this pattern in 2020 with an increase in HCFO recurrent cases may reflect the impact of the COVID-19 pandemic in 2020. Older persons, White individuals, and those with malignancies are particularly vulnerable to recurrent CDI.

Keywords: Chronic Disease Epidemiology, Thesis, Clostridioides difficile, CDI, recurrent CDI, recurrent Clostridioides difficile


This is an Open Access Thesis.

Open Access

This Article is Open Access