Hospitalized patients who are asymptomatic Clostridioides difficile carriers may infect people they live with after they return home, a study based on U.S. 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 wrote in Emerging Infectious Diseases.
“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, 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 said by email.
Dr. Miller and colleagues analyzed insurance claims data from 2001 through 2017 using the U.S. 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 3,871 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 had 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 compared with enrollees who were not exposed. The longer the family member’s hospital stay, the greater the risk that someone in the 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% confidence interval [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
Douglas S. Paauw MD, MACP, professor of medicine and the chair for patient-centered clinical education at the University of Washington, 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.”
Dr. Paauw advises doctors to consider CDI in their patients who have been exposed to hospitalized people.
David M. Aronoff, MD, FIDSA, FAAM, professor of medicine and the chair of the department of medicine at Indiana University, 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.
In a phone interview, Paul G. Auwaerter, MD, MBA, professor of medicine and clinical director of the division of infectious diseases at Johns Hopkins University, Baltimore, 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.”
Ramin Asgary, MD, MPH, FASTMH, associate professor of global health in the Milken Institute School of Public Health at George Washington University, Washington, 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 health care in general,” he said in an email.
Dr. 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.
A version of this article first appeared on Medscape.com.