Asymptomatic C. difficile Carriers May Infect Their Families Asymptomatic C. difficile Carriers May Infect Their Families

Hospitalized patients who are asymptomatic Clostridioides difficile carriers may infect people they live with after they return home, a study based on US insurance claim data suggests.

Although C. difficile infection (CDI) is considered to be a common hospital-acquired infection, reports of community-associated CDI in patients who have not been hospitalized are increasing, the authors write today in Emerging Infectious Diseases.

Aaron C. Miller, PhD

“Individuals in households where another family member was recently hospitalized but not diagnosed with a CDI appear to be at increased risk for CDI,” said lead author Aaron C. Miller, PhD, a research assistant professor in the Department of Internal Medicine at the University of Iowa Carver College of Medicine in Iowa City. “When individuals are hospitalized, they may become colonized with C. difficile without developing symptoms and subsequently transmit the pathogen to other family members after they return home,” he told Medscape Medical News by email.

Miller and his colleagues analyzed insurance claims data from 2001 through 2017 using the US Commercial Claims and Medicare Supplemental datasets of IBM MarketScan Research Databases. Over that period, they searched employer-sponsored commercial insurance claims and Medicare supplemental claims of 194,424 enrollees, and they linked claims from multiple family members in the same enrollment plan.

They identified 224,818 CDI cases, and 3871 of them were considered potential asymptomatic C. difficile transmissions from a recently hospitalized family member.

The researchers gathered monthly C. difficile incidence data from households with a family member who’d been hospitalized within the past 60 days and compared them with data from households without a hospitalized family member.

Enrollees exposed to a recently hospitalized family member had a 73% greater incidence of CDI than enrollees who were not exposed. The longer the family member’s hospital stay, the greater the risk that someone in their household became infected.

  • Compared with people whose family members were hospitalized less than 1 day, people whose family members were hospitalized from 1 to 3 days had an incidence rate ratio (IRR) of 1.30 (95% CI, 1.19 – 1.41), and those whose family members were hospitalized for more than 30 days had an IRR of 2.45 (95% CI, 1.66 – 3.60).

  • CDI incidence increased with age. Compared with people 17 years of age or younger, the IRR increased to 9.32 (95% CI, 8.92 – 9.73) for those over 65.

  • Females had higher CDI incidence than males (IRR 1.30; 95% CI, 1.28 – 1.33).

  • Households with an infant also had higher CDI incidence than those without (IRR 1.5; 95% CI, 1.44 – 1.58).

  • People taking antimicrobials had higher CDI IRRs: 2.69 (95% CI, 2.59 – 2.79) for low-CDI-risk antibiotics and 8.83 (95% CI, 8.63 – 9.03) for high-CDI-risk antibiotics.

  • People taking proton-pump inhibitors had an IRR of 2.23 (95% CI, 2.15 – 2.30).

Reactions From Four Experts

Dr Douglas Paauw

Douglas S. Paauw MD, MACP, a professor of medicine and the chair for patient-centered clinical education at the University of Washington School of Medicine in Seattle, was not surprised by the findings. “We have wondered for a while how community-acquired CDI occurs,” he said in an email. “This important study offers a plausible explanation for some cases.”

Paauw advises doctors to consider CDI in their patients who’ve been exposed to hospitalized people.

Dr David Aronoff

David M. Aronoff, MD, FIDSA, FAAM, a professor of medicine and the chair of the Department of Medicine at Indiana University School of Medicine in Indianapolis, advises providers to educate hospital patients being discharged about how CDI is spread and how they can practice good hand hygiene at home.

“An open question of this strong study is whether we should be testing certain hospital patients for asymptomatic C. difficile carriage before they are discharged,” he added in an email.

Dr Paul G. Auwaerter

In a phone interview, Paul G. Auwaerter, MD, MBA, a professor of medicine and the clinical director of the Division of Infectious Diseases at Johns Hopkins University School of Medicine in Baltimore, Maryland, noted that community-acquired CDI is frequent enough that his institution performs routine C. difficile testing on all patients with unexplained severe diarrhea.

“This intriguing study bears additional research and follow-up because clearly these spores are hardy,” he said. “But a key point in this billings- and claims-based study is that no one knows where household members acquired CDI, whether it was actually through household transmission.”

Dr Ramin Asgary

Ramin Asgary, MD, MPH, FASTMH, an associate professor of global health in the Milken Institute School of Public Health at George Washington University in Washington, DC, cautioned about “an increasing issue with drug-resistant CDI.”

“This important, timely study provides another step in the right direction to better understanding and addressing CDI and other hospital-based infections that have become increasing threats to the safety of our patients, their families, and healthcare in general,” he told Medscape Medical News in an email.

Miller said that the scale and scope of the data are strengths of the study, and he acknowledged that its basis in claims and billing data is a limitation. He and his group plan to explore genetic relationships involved in CDI transmission.

The study was funded by the Centers for Disease Control and Prevention. All authors and independent experts have disclosed no relevant financial relationships.

Emerg Infect Dis. Published online April 13, 2022. Full text

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