Introduction
Methods
Study design and setting
Prospective surveillance of MRSA-positive patients
Definition of a negative MRSA status
Microbiological diagnostic of MRSA
MRSA status of re-admitted patients
Observation period of initially MRSA-positive patients
Determination of the anatomical MRSA colonisation site of the patient
Determination of the MRSA status of a patient at the end of a hospital stay
Definition of the patient cohorts for the MRSA persistence analysis (univariate analysis, Kaplan–Meier survival analysis, Cox proportional hazards models)
Statistical analysis
Results
Characteristics | Number (%; unless otherwise stated) |
---|---|
Number of patients | 403 |
Male | 257 |
Age >65 years | 121 |
Age (years): (mean ± SD, median, range; 25-, 75-percentiles) | 52.9 ± 19.7, 57.0, 0–92; 41.0, 68.0 |
Duration of observation period (days): (mean ± SD, median, range; and 25-, 75- percentiles) | 301.2 ± 271.5, 210, 1–1325; 94, 435 |
MRSA status of patients at the time of discharge of their last observed admission during the study period | |
At all subsequent discharges MRSA-positive | 238 (59.1%) |
Only at the last observed re-admission MRSA-negative | 55 (13.6%) |
At the last observed at least two re-admissions MRSA-negative | 61 (15.1%) |
At one admission MRSA-negative followed by re-admission(s) with no confirmation of MRSA negativity | 22 (5.4%) |
At subsequent admissions switching MRSA status (positive–negative–positive, positive–negative–positive–negative–positive) | 27 (6.7%) |
Patients with MRSA colonisations at anatomical site groupsa
| |
Only nares | 48 (11.95%) |
Nares and other anatomical sites but no wounds | 114 (28.3%) |
Nares and other anatomical sites including wounds | 90 (22.3%) |
Throat, mouth, tracheal secretion, bronchial secretion or BAL without nares | 38 (9.4%) |
Only wounds | 21 (5.2%) |
Wounds and other anatomical sites without nares | 38 (9.4%) |
Other anatomical sites including urinary tract and ano-genital region without nares and without wounds | 34 (8.4%) |
Any other anatomical sites which are not already described above | 19 (6.7%) |
Unknown colonisation site | 1 (0.2%) |
Single anatomical colonisation site | 84 (20.9%) |
Multiple anatomical colonisation site | 318 (79.1%) |
Topical decolonisation therapy initiated during the first MRSA-positive admissionb
| 153 (38.8%) |
Variables | Patients re-admitted at least once | p value | |
---|---|---|---|
HR of MRSA loss | 95% CI for HR | ||
Age at first hospital stay (years) (>65/≤65 years) | 0.87 | 0.57–1.33 | 0.53 |
Topical decolonisation therapy initiated during the first hospital stay: Yes/no | 0.75 | 0.51–1.11 | 0.15 |
Anatomical site (total) | – | – | <0.01 |
Only wounds/only nares | 1.63 | 0.69–3.86 | 0.26 |
Nares and other anatomical sites but no wounds/only nares | 0.49 | 0.28–0.88 | 0.02 |
Throat, mouth, tracheal secretion, bronchial secretion or BAL without nares/only nares | 0.65 | 0.33–1.28 | 0.22 |
Nares and other anatomical sites including wounds/only nares | 0.34 | 0.19–0.63 | <0.01 |
Other anatomical sites including urinary tract and ano-genital region without nares and without wounds/only nares | 0.47 | 0.21–1.06 | 0.07 |
Wounds and other anatomical sites without nares/only nares | 0.83 | 0.41–1.67 | 0.59 |
Any other anatomical sites or combinations/only nares | 0.76 | 0.35–1.66 | 0.49 |
Unknown/only nares | 3.44 | 0.45–26.39 | 0.24 |
Discussion
Author | Study design | Investigated cohort | Number of investigated patients | Observation period; follow-up (months) | Principal topic | Decolonisation therapy | Effect of decolonisation therapy | MRSA persistence dependent on anatomical site | Clearance of MRSA (days) | Significant effect of age (years) | Comments: strengths and flaws of the publication |
---|---|---|---|---|---|---|---|---|---|---|---|
Scanvic et al. [15] | Prospective cohort study | HreAdma
| 78 | 10 (until Oct. 1998) | Colonisation and infection, Persistence of MRSA | Not applied | n.m. | n.m. | Percentile 50: 255 | n.m. | Only re-admitted patients >3 months after previous hospital stay, were included. No fixed timetable for control |
Marschall and Muhlemann [13] | Retrospective cohort study | HreAdm | 116 | 16.2 (until Dec. 2004) | Colonisation and infection, Persistence of MRSA | Nasally applied mupirocin, washing (4%) and gargling (0.1%) with chlorhexidine | MRSA loss: HR 2.22, 95% CI 1.36–3.64; p < 0.01 | n.m. | Percentile 60: 225 | Yes | Part of patients with decolonisation 31%. MRSA status “negative” was defined with 2 screenings with negative results |
Vriens et al. [16] | Retrospective cohort study | HreAdm, OutPat | 135 | By month 24, Median years 1.2 (Jan. 1991–Jan. 2001) | Colonisation and infection, Persistence of MRSA | Nasally applied mupirocin, washing with chlorhexidine; for gastro-intestinal carriage systemic antibiotic therapy | No data available | n.m. | Percentile 50: 320 | n.m. | Fixed time points month 6, 12, 18, 24. Intermittent carriers 9 (7%) |
Wendt et al. [25] | Prospective randomised, Placebo controlled double- blinded clinical trial | Study patients | 56 study group, 58 placebo group | 30 days (Jan. 2001–April 2004) | Colonisation of skin, nares and throat | Nasally applied mupirocin, washing (4%) with chlorhexidine | No significant difference | No | n.m. | n.m. | Only 30 days of controlled follow-up |
Harbarth et al. [23] | Prospective randomised, Placebo controlled double- blinded clinical trial | Study patients, only non-infected | 51 study group, 51 placebo group | 25 (until Sept. 1997) | Colonisation of skin, nares and urinary tract | Nasally applied mupirocin (study group), all: 4% chlorhexidine soap for daily baths or showers | No deco-lonisation-group: HR 1.55; 95% CI 0.97–2.47; p < 0.066 | MRSA persistence for ≥2 bodysites: HR 1.8; 95% CI 1.1–2.9; p < 0.01 | n.m. | no | Course of MRSA loss over a short period of 30 days after decolonisation |
Buehlmann et al. [22] | Prospective cohort study | All MRSA-positive patients | 62 | 36 (Jan. 2002–April 2007) | Colonisation and infection, Persistence of MRSA | Nasally applied mupirocin, daily chlorhexidine mouth rinse and body wash for 5 days; oral vancomycin for intestinal and cotrimoxazole for urinary tract colonisation | 87% of all patients after one up to 10 decolonisation cycles; 65% received peroral antibiotic treatment | MRSA loss: rate after 1 decolonisation for patients with 1 body site 76.9% and 38.7% for such with multiple sites (p < 0.004) | n.m. | n.m. | Only repeated decolonisation courses and the use of peroral antibiotic treatment was effective for decolonisation in many cases Ten recolonisations were typed by molecular methods, revealing eight with the same strain, one with another and one remained unknown. No time-dependent analysis and no cox-regression analysis were performed |
Robicsek et al. [14] | Retrospective cohort study | HreAdm | 648 | 14 (until Dec. 2007) | Colonisation or infection, Persistence of MRSA | Nasally applied mupirocin 4% washing with chlorhexidine | No significant difference in MRSA persistence found | MRSA persistence for pressure ulcera: OR 2.31, 95% CI 1.28–4.19; p < 0.006 | Percentile 50%: 360 | No significant differences found | Course of MRSA persistence over up to 4 years; no interval data available. Only re-admissions were considered |
Present study | Retrospective cohort study including all MRSA- positive patients in a university hospital | HreAdm | 1032 (1005) | By month 42, Median days 44 (Jan. 2002–Nov. 2005) | Colonisation or infection, Persistence of MRSA | Nasally applied mupirocin and daily whole body washes with octenidin for 5 days | MRSA loss after decolonisation therapy during the first hospital stay for all patients: OR 2.58 95% CI 1.59- 4.21; p < 0.01 | MRSA persistence for multiple bodysites: HR 2.18, 95% CI 1.52 – 3.15; p < 0.01 | Percentile 50: 566a
| No significant differences found | Investigation of a cohort over a long time-interval. Investigation of MRSA colonisation of different anatomical sites. No information about the MRSA status between hospital admissions |