Introduction
Cystic fibrosis (CF) is the most common life-limiting autosomal recessive disease in Caucasian populations. Thickened mucous secretion caused by the mutations on the CFTR gene leads to obstruction in the bronchioles secondary to mucus plugging. This causes an optimal environment for bacterial growth and infection1. Chronic pulmonary infection damaging the lung parenchyma and decreasing the pulmonary function is the leading cause of mortality and morbidity in individuals with CF 2-4. The most common microorganisms isolated from respiratory secretions in CF areStaphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa)4.
Chronic infection of P. aeruginosa is associated with more parenchymal damage, a more rapid decline in lung function, and earlier mortality 2; 5. The acquisition ofMethicillin-resistant S. aureus (MRSA), even though that is not seen as much as P. aeruginosa , causes a decline in forced expiratory volume in 1-second percent predicted (FEV1pp) and associated with worse survival6; 7. Current guidelines recommend antibiotic eradication treatment for MRSA and P. aeruginosa to prevent lung damage and chronic infections8; 9.
The antibiotic eradication treatment for P. aeruginosa and MRSA is an established standard of care worldwide9-13. However, the most effective route of administration of antibiotics (oral, inhalation or intravenous (IV)) and choice of antibiotic regimen are not clear. The two Cochrane reviews on this matter state that there is still insufficient data to decide on which antibiotic strategy should be used for the eradication of early P. aeruginosa or MRSA in CF14; 15.
There are numerous randomized controlled trials (RCT) on comparing different oral antibiotic regimens, oral vs. inhalation regimens and oral/inhalation combination regimens for P. aeruginosaeradication 14. While there are many retrospective studies comparing inhalation and oral antibiotic regimens, there are only two RCTs for MRSA eradication15. On the other hand, there are few studies comparing IV vs. oral/inhalation antibiotic regimens. To date, there is only one RCT comparing IV and non-parenteral antibiotics for the eradication of P. aeruginosa and there have been no published data that investigate the efficacy of IV compared to non-parenteral antibiotics to eradicate MRSA16.
Today, many CF clinics use IV antibiotics as antibiotic eradication treatment. IV eradication regimen requires hospital admission, IV access which might be traumatic and may worsen patient’s health-related quality of life (HRQoL) 17. Additionally, IV eradication regimens increase health-care costs significantly 16. In this study, we investigate the efficacy of IV vs. non-IV (oral and/or inhalation) antibiotic eradication treatments for the eradication of the first isolation of P. aeruginosa and MRSA in individuals with CF. Additionally, we aim to determine clinical variables associated with chronic infection of P. aeruginosa and MRSA.