2033. Incorporating T2Candida testing into rational antifungal (AF) management: A successful pilot study of diagnostic stewardship (DS) directed toward specific intensive care unit (ICU) patients (pts) at-risk for sepsis due to invasive candidiasis (IC)
Session: Poster Abstract Session: Diagnostics: Mycology
Saturday, October 6, 2018
Room: S Poster Hall

Background:  Blood cultures (BC) are ~50% sensitive for diagnosing IC.  T2Candida (T2) detects 5 leading Candida spp. directly in blood and was ≥90%/90% sensitive/specific (S/Sp) for candidemia in clinical trials. Optimal use of T2 in clinical practice is unclear. We targeted T2 to specific ICU pts at-risk for IC, and implemented AF management algorithms developed with ICU teams. 

Methods:   A DS team ordered concurrent T2 and BC, and used results to guide AF in pts fulfilling pre-specified criteria for septic shock (medical ICU (MICU)), sepsis after abdominal surgery (trauma ICU), or sepsis with mechanical circulatory support (cardiothoracic ICU). We focused on groups with anticipated pre-test IC probabilities of ~3-15%.  Proven IC was defined if BC+ and possible IC if BC- but a compatible clinical picture was observed.    

Results:  Seven percent (6/88) of BC in ICU pts with sepsis were Candida +.  T2 and BC results are shown in the Table.  Using BC as gold standard, T2 S/Sp and PPV/NPV were 50%/87% and 33%/96%, respectively.  Including possible IC, T2 S/Sp increased to 69%/96%, and 67% (4/6) of T2+/BC- results were likely true positive; 2 false positive results were for C. parapsilosis.  We focused on MICU outcomes initially since 75% (66/88) of tests were performed here.  Empiric AFs were discontinued in 12 pts following a T2- result; AFs were avoided in all others.  Median combined days of therapy (DOT)/month for caspofungin and fluconazole as empiric or definitive treatment prior to and after introducing DS were 26 (range: 10 – 53) and 15 (3 – 32), respectively (P=0.0047).  AF consumption was decreased 47% (Figure).     

Conclusion:   Targeted DS using T2 in select ICU pts with sepsis significantly reduced AF usage. 14% of pts with sepsis were diagnosed with IC using either T2+ or BC+, compared to 7% with BC+ alone, as would be expected if BC S was 50%.  T2 S and T2-/BC+ results were lower and higher, respectively, than previously reported, indicating that treatment decisions should be based on results of both tests.  Most T2+/BC- results were ascribed to possible IC.

Table. Rates of T2 and BC positive results and corresponding Candida species

 

% (n) tests

Candida spp

T2+

10% (9)

5 CP, 4 CA/CT

BC+

7% (6)

5 CA, 1 CP

T2+/BC+

3% (3)

2 CA, 1 CP

T2+/BC-

7% (6)

2 CA/CT, 4 CP

T2-/BC+

3% (3)

3 CA

T2-/BC-

86% (76)

 

Figure 1. Antifungal days of therapy (DOT) per month in the MICU

Ryan K. Shields, PharmD1, Cornelius J. Clancy, M.D.2, Rachel V. Marini, PharmD3, Lara Groetzinger, PharmD4, Ryan Rivosecchi, PharmD4, Bonnie Falcione, PharmD, BCPS AQ-ID5, Anthony Pasculle, ScD6 and M. Hong Nguyen, MD7, (1)University of Pittsburgh, School of Medicine, Pittsburgh, PA, (2)Infectious Diseases, University of Pittsburgh, Pittsburgh, PA, (3)Pharmacy, UPMC Presbyterian Hospital, Pittsburgh, PA, (4)University of Pittsburgh, Pittsburgh, PA, (5)Antibiotic Management Program, University of Pittsburgh Medical Center, Pittsburgh, PA, (6)Microbiology, University of Pittsburgh Medical Center, Pittsburgh, PA, (7)Infectious Disease, University of Pittsburgh, Pittsburgh, PA

Disclosures:

R. K. Shields, None

C. J. Clancy, None

R. V. Marini, None

L. Groetzinger, None

R. Rivosecchi, None

B. Falcione, None

A. Pasculle, None

M. H. Nguyen, Merck: Grant Investigator , Research grant . Astellas: Grant Investigator , Research grant .

Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.