NYMC Faculty Publications


Use of a Perianal Swab Compared With a Stool Sample to Detect Symptomatic Clostridium difficile Infection

Document Type


Publication Date




Second Department



OBJECTIVE To evaluate the use of a perianal swab to detect CDI. METHODS A perianal swab was collected from each inpatient with a positive stool sample for C. difficile (by polymerase chain reaction [PCR] test) and was tested for C. difficile by PCR and by culture. The variables evaluated included demographics, CDI severity, bathing before perianal swab collection, hours between stool sample and perianal swab, cycle threshold (Ct) to PCR positivity, and doses of CDI treatment before stool sample and before perianal swab. RESULTS Of 83 perianal swabs, 59 (71.1%) tested positive for C. difficile by PCR when perianal swabs were collected an average of 21 hours after the stool sample. Compared with the respective stool sample, the perianal sample was less likely to grow C. difficile (P=.005) and had a higher PCR Ct (P

Publisher's Statement

Originally published in Infection Control and Hospital Epidemiology, 38 (6), 658-662. The original material can be found here.