Risk for Asymptomatic Household Transmission of Clostridioides Difficile Infection Associated With Recently Hospitalized Family Members

Aaron C. Miller; Alan T. Arakkal; Daniel K. Sewell; Alberto M. Segre; Sriram V. Pemmaraju; Philip M. Polgreen


Emerging Infectious Diseases. 2022;28(5):932-939. 

In This Article

Abstract and Introduction


We evaluated whether hospitalized patients without diagnosed Clostridioides difficile infection (CDI) increased the risk for CDI among their family members after discharge. We used 2001–2017 US insurance claims data to compare monthly CDI incidence between persons in households with and without a family member hospitalized in the previous 60 days. CDI incidence among insurance enrollees exposed to a recently hospitalized family member was 73% greater than enrollees not exposed, and incidence increased with length of hospitalization among family members. We identified a dose-response relationship between total days of within-household hospitalization and CDI incidence rate ratio. Compared with persons whose family members were hospitalized <1 day, the incidence rate ratio increased from 1.30 (95% CI 1.19–1.41) for 1–3 days of hospitalization to 2.45 (95% CI 1.66–3.60) for >30 days of hospitalization. Asymptomatic C. difficile carriers discharged from hospitals could be a major source of community-associated CDI cases.


Clostridioides difficile infection (CDI) is one of the most commonly occurring types of healthcare-associated infection and is predominately associated with hospitals.[1,2] Thus, CDI-related investigations and interventions primarily have focused on hospital settings. More recently, reports of community-associated CDI cases, in which patients without a history of recent hospitalization are infected, have become more common.[3,4] Although healthcare-associated CDI remains a considerable problem, more emphasis on community-associated CDI cases also is needed.

Risk factors for community-associated CDI are similar to risk factors for hospital-associated cases. For example, antimicrobial drug and proton-pump inhibitor (PPI) use increase the risk for community-associated CDI.[4,5] For some community-associated CDI cases, exposure to healthcare settings beyond hospitalization, including clinics and emergency departments,[6,7] are associated with an increased risk for CDI. However, for some CDI cases, no clear exposure to healthcare facilities can be identified. To find a source of C. difficile in community settings, other potential exposures have been proposed. Food is one such potential exposure, and C. difficile has been recovered from several different edible substances, including meat and vegetables.[8,9] Pets have also been implicated.[10] In addition, the possibility of household transmission of CDI between family members has been proposed, and having a symptomatic family member is a risk factor for CDI.[10,11]

In addition to symptomatic CDI cases, patients with asymptomatic C. difficile colonization might contribute to transmission.[12,13] In whole-genome sequencing studies, identifying epidemiologic links between symptomatic CDI among hospitalized patients has often been difficult,[14,15] suggesting a potential role for asymptomatic C. difficile colonization. Asymptomatic colonized patients might contribute less to environmental contamination than symptomatic cases, but in sufficient numbers they could still play a role in C. difficile transmission in healthcare settings.[16] Furthermore, if asymptomatically colonized patients contribute to C. difficile transmission within the hospital, then they could contribute to transmission in the community after they are discharged and especially could play a role in transmission among other household members. Finally, because hospitalized patients can remain asymptomatically colonized with C. difficile after discharge,[17–20] this patient population could represent a large reservoir of CDI outside healthcare settings.

We investigated whether recently hospitalized patients increased the risk for CDI among household members in the period after discharge. Specifically, we were interested in the risk posed to household members by patients who are discharged without a CDI diagnosis and who are not diagnosed with CDI after discharge. If the risk for asymptomatic C. difficile colonization increases with length of stay, we hypothesized that the risk for CDI among household members should increase as a function of their recently hospitalized family members' lengths of stay.