The impact of a chronic colonization with MRSA in individuals with cystic fibrosis is still a matter of debate. Some studies documented a worsening of pulmonary disease and accelerated loss of lung function in CF patients colonized with MRSA [
1‐
3,
6,
7]. On the other hand, some studies suggest that acquisition of MRSA is not associated with an accelerated loss of lung function [
12]. Although a positive effect on pulmonary disease and lung function parameters is not proven yet, there are other issues that have to be considered. Because of the contact precautions, which are necessary for patients with chronic MRSA colonization, they are often unable to receive important therapeutic measures which are part of the routine treatment for CF patients in Germany: In particular the outpatient physiotherapy, which is performed once a week by a specially trained physiotherapist and the rehabilitations are frequently withheld from the patients. This might be different in other countries, but in our opinion this is an important reason to eradicate MRSA. Several CF centers therefore aim at an early eradication of MRSA immediately after its first detection. The protocols used for the eradication attempts are difficult to compare as they differ in terms of the type, administration route and duration of antibiotic therapy. The success rate of eradication observed with our protocol (86%) compares well to other published schemes, in which the success rates ranged from 55% (Solis et al.) [
13] to 94% (Macfarlane et al.) [
8]. However, the published studies are not directly comparable, as there are many differences especially with respect to the applied antibiotics, the duration of the therapy, and the follow-up period (see Table
4 for more details). A notable advantage of our eradication protocol is its short duration of 7 days. This might not only lead to a better compliance of the patients, but should also have a positive impact with respect to side effects and the development of antibiotic resistance. The fact that the eradication scheme was performed in an inpatient hospital setting is likely to be an important factor for the high success rate, because adherence to the therapy and especially the implementation of the local measures will be higher under direct supervision than at home. In our opinion eradication according to this protocol at home would lead to a significantly lower success rate. However, as there was no control group who underwent the eradication protocol at home, this remains to be formally demonstrated. In Germany, the inpatient hospital stays are covered by the health insurances. Therefore, we have to admit that this protocol may not be feasible in other countries. Our protocol consists of three parts (local measures, oral rifampicin and fusidic acid and inhaled vancomycin). Unfortunately, we are unable to make a statement on the impact of each individual measurement on the overall success of our protocol. In particular the value of the inhaled vancomycin remains unclear. However, treatment periods longer than 7 days are probably not more successful, as we observed comparable clearance rates. In summary our protocol was well tolerated an accepted by the patients and provided an effective way to eradicate MRSA. The fact that none of the patients who have been offered the eradication procedure refused to undergo the treatment or interrupted the protocol emphasizes the compliance of the patients and the acceptance of the procedure.
Table 4
Overview on studies that evaluated different antibiotic protocols for the eradication of MRSA after its first detection
| 12 | median 9.8 (0,6–17) | 5 days topic/inhaled vancomycin | 58 |
| 17 | mean 12.3 (1.8–16.5) | 1. oral rifampicin and fusidic acid over 5 days | 47% |
2. If still positive: oral rifampicin and fusidic acid over additional 5 days | 71% |
3. If still positive: intravenous teicoplanin | 94% |
| 29 | mean 30 (17–62) | either single or dual oral antibiotic therapy, until negative sputum, minimum 2 weeks, maximum 8 weeks | single therapy 50% dual therapy 85% |
| 37 | mean 15.3 (0.6–36.9) | 3 weeks dual intravenous + 6 weeks dual oral antibiotics + inhaled vancomycin if still positive 6 weeks inhaled vancomycin | 84 |
Muhlebach et al. | 22 | mean 12.3 (SD 6.6) | 2 weeks dual oral antibiotics (rifampicin and trimethoprim/sulfamethoxazole or rifampicin an minocycline) | 82 |
Muhlebach et al. Observational control [ 16] | 19 | mean 10.5 (SD 5.5) | none | 26 |
this study | 7 | Median 15 (4–30) | Oral rifampicin and fusidic acid + inhaled vancomycin over 7 days | 86 |
Major limitations of our study are the low number of cases and the retrospective design. In addition, we used different specimens (sputum and/or deep oropharyngeal swab) to detect MRSA. This was necessary because some patients were unable to produce sputum. Previous publications suggested that cultures of oropharyngeal swabs are not reliable to predict the presence of bacterial pathogens in the lower airways of cystic fibrosis patients [
14,
15]. However, given the fact that we collected three independent specimens for culture after MRSA eradication and that the patients remained negative for a median period of 16 months, we believe that the risk of a false negative result is minimal. Moreover, the heterogeneity of the patients with respect to age, sex and coinfection or co-colonization with other bacteria such as
Pseudomonas aeruginosa and
Burkholderia cepacia made it impossible to demonstrate a positive clinical effect of MRSA eradication in our patients. Furthermore, we were unable to compare our results to a control group of patients that were not offered eradication. A recent publication showed a spontaneous elimination of MRSA of only 26% of the affected patients [
16]. In our opinion this emphasizes the importance of MRSA eradication, which, in our opinion will be beneficial for the patients in the long run.
As mentioned above and confirmed recently by the Cochrane Collaboration [
9,
10], a comparison of all published eradication schemes is not possible. Further and prospective studies comparing several eradication protocols for MRSA would be useful.