3
Diagnosis
S, strong ; W, weak; H, high; M, moderate; L, low; VL, very low quality of evidence;
GP, good practice; NR, no recommendation
Adult
➤ Patients with unexplained and new onset ≥3 unformed stools in 24 h
are the preferred target population for testing for CDI (W-VL).
➤ Use a stool toxin test as part of a multiple step algorithm (i.e.,
glutamate dehydrogenase [GDH] plus toxin; GDH plus toxin, arbitrated
by nucleic acid amplification test [NAAT]; or NAAT plus toxin) rather
than a NAAT alone for all specimens received in the clinical laboratory
when there are no pre-agreed institutional criteria for patient stool
submission (see Figure 1) (W-L).
➤ Use a NAAT alone or multiple step algorithm for testing (i.e., GDH plus
toxin; GDH plus toxin, arbitrated by NAAT; or NAAT plus toxin) rather
than a toxin test alone when there are pre-agreed institutional criteria
for patient stool submission (see Figure 1) (W-L).
➤ Do not perform repeat testing (within 7 days) during the same episode
of diarrhea and do not test stool from asymptomatic patients, except
for epidemiological studies (S-M).
➤ There are insufficient data to recommend use of biologic markers as an
adjunct to diagnosis (NR).
Pediatric
➤ Because of the high prevalence of asymptomatic carriage of toxigenic
C. difficile in infants, testing for CDI should never be routinely
recommended for neonates or infants ≤12 months of age with
diarrhea (S-M).
➤ C. difficile testing should not be routinely performed in children with
diarrhea who are 1–2 years of age unless other infectious or non-
infectious causes have been excluded (W-L).
➤ In children 2 years and older, C. difficile testing is recommended for
patients with prolonged or worsening diarrhea and risk factors (such
as underlying inflammatory bowel disease or immunocompromising
conditions) or relevant exposures (such as contact with the healthcare
system or recent antibiotics) (W-M).
