One of the most prevalent, stubborn and dangerous health-care-associated infections, C. diff (Clostridioides difficile), is linked mainly to hospitals.
But new evidence suggests patients — even those without symptoms — might spread the bug in their homes.
To explain a spate of C. diff cases outside of hospitals, experts have implicated everything from foods to pets to farms.
But a study published by the Centers for Disease Control and Prevention in Emerging Infectious Diseases found exposure to a recently hospitalized family member raised infection likelihood 73%, with longer hospital stays linked to greater risk.
That suggests asymptomatic patients could be spreading C. diff to their families.
Previous studies show household spread of other hospital-associated bacteria, including MRSA (methicillin-resistant Staphylococcus aureus).
The greatest C. diff risk occurred among people who were female, 40 and older, or were taking antibiotics or proton-pump inhibitors.