Family Members of Hospitalized Patients at Increased Risk of CDI

Aaron Miller, PhD

Living in the same household of someone hospitalized could increase the risk of developing a clostridium difficile infection (CDI).

A team, led by Aaron C. Miller, PhD, University of Iowa, identified whether hospitalized patients without CDI increased the risk of the infection among their family members following discharge.

C Difficile Studies

The majority of CDI studies have focused on preventing the spread of hospital-acquired infections.

“Asymptomatic C. difficile carriers discharged from hospitals could be a major source of community-associated CDI cases,” the authors wrote. “Although healthcare-associated CDI remains a considerable problem, more emphasis on community-associated CDI cases also is needed.”

While there are likely similar risk factors between hospital-acquired CDI and community-spread C difficile infections in antibiotic use and age, there could be some unique risk factors in the community, including food and pets, as well as having a symptomatic family member.

Insurance Data

In the study, the investigators used US insurance claims data between 2001-2017 to compare the monthly incidence of CDI between individuals in households with and without a family member hospitalized in the previous 60 days.

The study population included patients with at least 2 family members who could be identified on the same insurance plan. Overall, there were more than 142 million enrollees with at least 2 family members enrolled in the same insurance plan for an entire month, with over 5.1 billion total enrollments during the entire 17-year study period.

Of this group, there were 224,818 CDI cases identified across 194,424 enrollees.

The analysis was based on monthly CDI incidence. The investigators also used a regression model to stratify enrollees into monthly enrollment strata based on the year and month, as well as other demographic and patient characteristics, including age, sex, prior antimicrobial drug use, proton pump inhibitor use, the presence of an infant under 2 years of age in the household, and exposure to a recently hospitalized family member.

Incidence Rates

Overall, they found incidence of C difficile infections among insurance enrollees exposed to a recently hospitalized family member was 73% greater than enrollees who were not exposed.The incidence also increased the length of hospital stay among family members.

The CDI incidence rate was also greater among enrollees in households of recently hospitalized members. Cases increased from 3.22 cases per 100,000 enrollment months for 9 days of within-household hospitalization to 8.73 cases per 100,000 enrollment months for more than 30 total days of within-household hospitalization.

The investigators found a dose-response relationship between the total days of within-household hospitalization and the CDI incidence rate ratio.

The incidence rate ration 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 family members of individuals hospitalized for more than 30 days.

Antibiotics

Finally, the investigators found that known risk factors were associated with a greater incidence rate of CDI. For example, antimicrobial drug exposure was linked to an increased incidence rate.

For low-CDI-risk antibiotics, the IRR was 2,69 (95% CI, 2.59-2,79, compared to an IRR of 8.83 (95% CI, 8.63-9.03) for high-CDI-risk antibiotics.

PPI use was also linked to a statistically significant incidence rate, with an IRR of 2.23 (95% CI, 2.15-2.30).

“In this study, we found that persons exposed to recently hospitalized family members were at substantially increased risk for CDI within 60 days after the family member’s hospital discharge,” the authors wrote. “Because CDI was not diagnosed in recently hospitalized and discharged family members during or after their hospitalization, and because persons in our analysis were not hospitalized themselves, the increased risk could be attributable to asymptomatic C. difficile colonization at the time of hospital discharge in the hospitalized family member.”

The study, “Risk for Asymptomatic Household Transmission of Clostridioides difficile Infection Associated with Recently Hospitalized Family Members,” was published online in Emerging Infectious Diseases.