Carbapenem-resistant Enterobacteriaceae (CRE) infections are associated with high
mortality worldwide, primarily due to delayed administration and limited availability
of effective antibiotics. Some CRE produce carbapenemases, which confer increased
resistance that can be transmitted horizontally to other Gram-negative bacteria. Although
some carbapenemases, including Klebsiella pneumoniae carbapenemase, are now considered
endemic in the United States, New Delhi metallo-β-lactamases (NDM) remain unusual
in the U.S. and are typically associated with receipt of healthcare abroad. Here,
we characterize the epidemiological investigation and infection prevention interventions
implemented after an NDM-producing CRE was identified at a 490-bed academic pediatric
hospital in Texas in a lymphoma patient admitted to the intensive care unit with no
history of international travel.
Epidemiological investigation included a six-month retrospective review of CRE cases,
point-prevalence survey for carriage of carbapenemase-producing isolates among inpatients
admitted to the same unit as the index patient, and three-month prospective surveillance
for carbapenem resistance. Infection prevention interventions were implemented to
prevent hospital-based transmission of CRE.
Six-month retrospective surveillance identified 11 CRE, but no high-level resistance
or carbapenemase production. Carbapenemases were not detected in point-prevalence
testing of 17 patients concurrently hospitalized in the same unit or in four additional
CRE isolates identified during prospective surveillance. Infection prevention interventions
included staff education; contact precautions and hand hygiene audits; additional
cleaning measures in index patient rooms, including daily floor disinfection and ultraviolet
light terminal disinfection; and continuation of contact precautions for the index
patient during any subsequent admissions and outpatient visits.
Our investigation did not detect evidence of hospital-based transmission of NDM-CRE,
suggesting the index isolate may have been acquired in the community and highlighting
the potential for local transmission of NDM-producing isolates even in the absence
of previously characterized risk factors. Ongoing surveillance and infection prevention
strategies are necessary to detect CRE and prevent its transmission.