Management of Extreme Resistant (XDR) Acinetobacter (AB) Cluster in a Medical (M) ICU at the University of Pittsburgh Medical Center (UPMC)

Background: AB has been associated with outbreaks in healthcare settings, has been shown to persist in healthcare environments and effectively colonizes skin. UPMC is a complex 750 bed tertiary care center with a case-mix index of 2.4.  In Jul 2015, 2 MICU patients were found to harbor XDR AB. The MICU primarily houses lung transplant, acute and chronically ill pulmonary patients. Incidence increased over a 6 month period.   A multidisciplinary investigation ensued to better characterize and terminate the cluster.

Methods:  Cases were evaluated for commonalties.  An XDR AB reduction bundle was implemented.  XDR AB point prevalence (PP) screening was conducted using modified Leeds AB medium to identify undetected cases.

Interventions included: 

Focused/supervised environmental cleaning

XDR AB rooms were identified with an additional visual cue (blue tape)

Room observers

Ensure compliance with hand hygiene (HH) and personal protective equipment (PPE)

Staff signature required for entrance

Increased HH and PPE observations

Dedicated caregivers/equipment

Discharge ultraviolet disinfection

PP XDR AB screening

Pulse field gel electrophoresis (PFGE) molecular typing was performed to assess clonal relatedness 

After no new clinical culture positivity, a PP study was performed

Results:

13 unique MICU patients were identified as incident XDR AB

8 isolates were available for PFGE typing

6/8 were highly related based on a grouping level of 90.5%

2/6 were indistinguishable

2/8 were unrelated

No common equipment was identified as a vector for transmission

PP XDR AB screening

Oct 2015 – 0/64 + XDR AB

April 2016 – 0/32 + XDR AB

Bundle implementation was associated interruption of transmission

                                     

Conclusion: 

XDR AB are associated with clusters in healthcare.

After exposure, patients can develop infections that are difficult to treat and associated with high morbidity and mortality.

Molecular typing can help characterize clonal clusters and direct appropriate Infection Prevention interventions.

Focused attention to HH, PPE compliance and enhanced environmental disinfection, to include UV disinfection, were important interventions in stemming this outbreak.