Table 1.
Description of results, time and cost of microbiological analysis during two phases of the investigation of two cases of glycopeptide-resistant Enterococci
| |
Investigation of the first case in the diabetology unit |
Investigation of a secondary case in the nephrology unit |
|---|---|---|
| (n=31 patients) | (n=22 patients) | |
|
Test Results, n (%) |
|
|
| Cepheid Xpert™ vanA/vanB assay: |
|
|
| Negative PCR |
1 (3)a |
17 (77) |
| Positive vanA |
1 (3)a |
0 (0) |
| Positive vanB and culture showing susceptible strain |
- |
2 (9) |
| PCR invalid then negative culture |
- |
2 (9) |
| PCR invalid then culture showing susceptible stain |
- |
1 (5) |
| Culture after enrichment using chromogenic medium: |
|
|
| Negative culture |
26 (84) |
- |
| Culture positive for GRE strainb |
1 (3)a |
- |
| Culture positive for susceptible Enterococcusc |
4 (13) |
- |
|
Turn-around time (hours, median [Q1-Q3]) |
|
|
| From sampling, to sample reception |
2.6 (1.7-2.6) |
2.8 (1.1 – 3.8) |
| From sample reception, to inoculation or preparation |
2.3 (2.2– 2.4) |
1.3 (0.5 – 2.3) |
| From inoculation or preparation, to results |
65.5 (65.5– 65.5) |
1 (0.9-1.1) |
| From sample reception, to results |
67.8 (68.4 – 67.9) |
6.22 (3.7 – 8.2) |
| From sampling, to results |
70.5 (69.4 – 70.5) |
4.6 (4.0 – 18.9) |
| Maximal time to obtain all results |
70.5 |
90.0 |
|
Cost of microbiological analysis (€) |
|
|
| Cepheid Xpert™ vanA/vanB assay: |
|
|
| Cost of 1 cartridge |
- |
35.60 |
| Cost of 1 test |
- |
37.30 |
| Culture with chromogenic medium and enrichment |
|
|
| Cost of a negative culture |
4.80 |
- |
| Cost of a doubtful culturec |
13.40 |
- |
| Cost of a doubtful cultured |
23.50 |
- |
| Cost of a positive cultureb |
117.80 |
- |
| Total cost of microbiological testing |
333.50 |
870.40 |
|
Loss of income |
|
|
| Cost per weighted case per day in 2011e |
340.70 |
426.00 |
|
Scenario 1: Implementation of local guidelines |
|
|
| Patient-days lost f |
41 |
0 |
| Estimated loss of income (€) |
13,968.70 |
0 |
|
Scenario 2: Implementation of national guidelines |
|
|
| Patient-days lostf |
250 |
0 |
| Estimated loss of income (€) |
85,175.00 |
0 |
|
Overall loss of income (€) |
13,968.70 to 85,175.00 |
0 |
| Overall cost of the strategy (€) | 14,302.20 to 86,175.50g | 870.40 to 2,611.20g |
PCR, polymerase chain reaction; GRE, Glycopeptide-Resistant Enterococci ; Q1, First quartile; Q3, Third quartile.
aReal-time PCR assay performed on an exceptional basis to screen the two patients who shared the room of the first patient in the diabetology ward.
bPositive culture with identification of E. faecium by mass spectrometry assay, MICs >8 mg/L for vancomycin and/or teicoplanin on E-test strips, antibiotic susceptibility testing by disk diffusion in solid media for clinical purpose, and detection of the vancomycin resistance genotype by DNA strip assay.
cPositive culture with identification of Enterococcus faecium by mass spectrometry assay with MICs ≤8 mg/L for vancomycin and/or teicoplanin on E-test strips.
dPositive culture with identification of E. faecium by mass spectrometry assay, MICs >8 mg/L for vancomycin and/or teicoplanin on E-test strips, and antibiotic susceptibility testing by disk diffusion in solid media for clinical purpose.
eEstimated costs of inpatient care based on reimbursement rates of the diagnosis-related group. In France, the diagnosis-related group price is calculated by multiplying standard amounts for operating and capital expenses found in yearly surveys by a national “weight” associated with the DRG for each hospitalisation. The weighting takes in account variations due to geographic area and atypical observations.
fNumber of missed patient-days due to the interruption of patients’ transfers and admissions.
gCosts estimation assuming the strict implementation of French national guidelines with three weekly screening of patients.