Point-of-Care Testing for Clostridium Difficile Infection: A Real-World Feasibility Study of a Rapid Molecular Test in Two Hospital Settings

Introduction: In the developed world,
Clostridium difficile infection (CDI) is the most
important cause of nosocomial infectious
diarrhea. In addition to providing
epidemiological data and helping to indicate
that a local outbreak may be occurring,
laboratory tests are used to augment clinical
decisions on individual patients. Very rarely do
diagnostic tests provide results at the point of decision making; in the intervening period
between requesting investigations on a patient
with suspected CDI and return of the laboratory
result, decisions must be made regarding
patient isolation and treatment.
Methods: A 22-month, real-world feasibility
study was conducted in patients with clinically
significant diarrhea, in a London Hospital
between March 2011 and January 2013, in
three older persons’ wards and two intensive
care units (ICUs) to determine acceptability,
ease of use, change in turnaround time and
clinical utility of a rapid, polymerase chain
reaction (PCR)-based point-of-care test (POCT)
(Cepheid GeneXpert, Sunnyvale, California,
USA) for diagnosis of Clostridium difficile. Nurses
in the older persons’ ward and laboratory
technicians in the ICU were trained to
perform the test. Residual samples were sent to
the centralized laboratory for parallel testing
using a two-step algorithm.
Results: A total of 335 samples were tested using
the POCT with a median turnaround time of
1.85 h compared with 18 h for the centralized
laboratory test. Overall agreement with
centralized laboratory testing was 98.1%.
Discrepant samples were more frequent on elderly wards than ICU. Overall 20/335 (6%)
processing errors were encountered and were
highest in the first few months of the study.
Significantly more processing errors occurred on
the older persons’ wards 13/102 (12.7%) than on
ICU 7/271 (2.6%). Older persons’ patients who
had POCT were significantly less likely to have a
test requested for bacterial stool culture (3.1% vs.
10.9% p = 0.044). This difference was not
observed in the ICU patients. No other
differences in ancillary test requesting,
mortality or length of stay were observed.
Conclusions: The majority of users reported
that the POCT was easy to perform and was an
acceptable part of their job. POCT using this
system is feasible and acceptable to nursing staff
and technicians working within these two
hospital-based settings.