Socioeconomic Status Factors Associated with Increased Incidence of Community-Associated Clostridium difficile Infection

BACKGROUND: Traditionally a hospital-acquired pathogen, Clostridium difficile is increasingly recognized as an important cause of diarrhea in community settings. Health disparities in C. difficileinfection (CDI) have been reported, but little is known about the social determinants of health that influence community-associated (CA) CDI incidence. We sought to identify socioeconomic status (SES) factors associated with increased CA-CDI incidence. METHODS: Population-based CDI surveillance is conducted in 35 U.S. counties through the Centers for Disease Control and Prevention’s Emerging Infections Program. A CA-CDI case is defined as a positive C. difficile stool specimen collected as an outpatient or within three days of hospitalization in a person aged ≥ 1 year who did not have a positive test in the prior 8 weeks or an overnight stay in a healthcare facility in the prior 12 weeks. ArcGIS software was used to geocode 2014–2015 CA-CDI case addresses to a 2010 census tract (CT). Incidence rate was calculated using 2010 Census population denominators. CT-level SES factors were obtained from the 2011–2015 American Community Survey 5-year estimates and divided into deciles. To account for CT-level clustering effects, separate generalized linear mixed models with negative binomial distribution were used to evaluate the association between each SES factor and CA-CDI incidence, adjusted by age, sex and race. RESULTS: Of 9686 CA-CDI cases, 9417 (97%) had addresses geocoded to a CT; of these, 62% were female, 82% were white, and 35% were aged ≥65 years. Annual CA-CDI incidence was 42.9 per 100,000 persons. After adjusting for age, sex and race, CT-level SES factors significantly associated with increased CA-CDI incidence included living under the poverty level (rate ratio [RR] 1.12; 95% confidence interval [CI] 1.09–1.53), crowding in homes (RR 1.11; 95% CI 1.01–1.21), low education (RR 1.11; 95% CI 1.07–1.15), low income (RR 1.15; 95% CI 1.12–1.17), having public health insurance (RR 1.21; 95% CI 1.18–1.24), receiving public assistance income (RR 1.69; 95% CI 1.55–1.84), and unemployment (RR 1.14; 95% CI 1.07–1.22). CONCLUSION: Areas with lower SES have modestly increased CA-CDI incidence. Understanding the mechanisms by which SES factors impact CA-CDI incidence could help guide prevention efforts in these higher-risk areas. DISCLOSURES: All authors: No reported disclosures.