Review question

We looked for evidence for the effects of different ways of clearing meticillin-resistant Staphylococcus aureus (MRSA) from the lungs of people with cystic fibrosis.

Background

MRSA is the name given to particular bacteria which are resistant to some types of antibiotics. This is particularly worrying for people with cystic fibrosis, which is an inherited condition which amongst other things causes thick mucus to build up in the lungs. It is very difficult for people with cystic fibrosis to cough up this thick mucus, making it an ideal breeding ground for bacteria, including MRSA, and making these people more prone to chest infections. It is thought that MRSA can cause more damage than other bacteria, which are not resistant to antibiotics. We wanted to identify research evidence to support the best way for treating MRSA infections and also to see if this would improve the lives of people with cystic fibrosis. This is an update of a previously published review.

Search date

The evidence is current to: 27 July 2017.

Key results

We found two trials which included people with cystic fibrosis and a diagnosed MRSA infection. In one trial the active treatment was oral trimethoprim and sulfamethoxazole combined with rifampicin and some additional decontamination treatment and in the second trial it was oral co-trimoxazole and rifampicin with intranasal mupirocin; in both trials the comparison treatment was just observation and no active treatment. The results of these trials showed that clearing MRSA from the airways of people with CF is possible. Although a larger proportion of those who were treated became clear of MRSA in both trials, some of the individuals who were untreated also cleared MRSA spontaneously. Also, six months after treatment, the number of individuals who still had MRSA was not different between those who received treatment and those who did not.

In one of the trials, fewer people who were treated with antibiotics were admitted to hospital in the first 168 days. There were no other differences seen between the two groups (treated or untreated) in terms of their lung function, weight or chest exacerbations at six months.

Treating MRSA early in people with CF has been shown to be possible, but it is not clear what longer-term implications this will have.

Quality of the evidence

Using GRADE methodology, we judged the quality of the evidence we found to be very low to low for the different outcomes. This was due to potential issues from the trial design where people knew which treatment each of the participants were receiving (groups were either given medication or just observed) and because there were small numbers of people included in each trial. Also, one of the trials did not report all details clearly.