Molecular Epidemiology of Clostridioides difficile Colonization in Families With Infants.

ABSTRACT

Background: Community-associated Clostridioides difficile infection is a major public health hazard to adults and older children. Infants frequently excrete toxigenic C difficile asymptomatically in their stool, but their importance as a community reservoir of C difficile is uncertain. Methods: Families of healthy infants were recruited at the baby's 4-month well child visit and were followed longitudinally until the baby was approximately 9 months old. Babies and mothers submitted stool or rectal swabs every 2 weeks that were cultivated for C difficile; fathers' participation was encouraged but not required. Clostridioides difficile isolates were strain-typed by fluorescent polymerase chain reaction ribotyping and by core genome multilocus sequence typing, and the number of families in whom the same strain was cultivated from >1 family member ("strain sharing") was assessed. Results: Thirty families were enrolled, including 33 infants (3 sets of twins) and 30 mothers; 19 fathers also participated. Clostridioides difficile was identified in 28 of these 30 families over the course of the study, and strain sharing was identified in 17 of these 28. In 3 families, 2 separate strains were shared. The infant was involved in 17 of 20 instances of strain sharing, and in 13 of these, the baby was identified first, with or without a concomitantly excreting adult. Excretion of shared strains usually was persistent. Conclusions: Clostridioides difficile strain sharing was frequent in healthy families caring for an infant, increasing the likelihood that asymptomatically excreting babies and their families represent a reservoir of the organism in the community.