CF START: A national UK trial to determine whether taking an antibiotic (flucloxacillin) every day predisposes infants with cystic fibrosis (CF) to earlier infection with a bug, Pseudomonas aeruginosa, that is resistant to treatment

Recruitment & Eligibility

Status: Ongoing

Sex: All

Target Recruitment: 485

Inclusion Criteria

Current inclusion criteria as of 13/04/2021:
1. A confirmed diagnosis of cystic fibrosis through one of the following three routes:
1.1. Two CF-causing mutations are identified
OR
1.2. One or no CF- causing mutations identified and a sweat chloride test result greater than 59 mmol/L
OR
1.3. Two CFTR mutations (not known CF-causing mutations) and a sweat chloride test result greater than 29 mmol/L
2. Age 90 days or less
3. Consent for inclusion on the national UK CF Registry
4. Consent for inclusion in the CF START trial

Previous inclusion criteria:
1. A confirmed diagnosis of cystic fibrosis through one of the following three routes:
1.1. Two CF-causing mutations are identified
OR
1.2. One or no CF- causing mutations identified and a sweat chloride test result greater than 59 mmol/L
OR
1.3. Two CFTR mutations (not known CF-causing mutations) and a sweat chloride test result greater than 29 mmol/L
2. Age 70 days or less
3. Consent for inclusion on the national UK CF Registry
4. Consent for inclusion in the CF START trial

Exclusion Criteria

1. An inconclusive diagnosis after newborn screening (NBS)*
2. A condition (non-CF) that, in the opinion of the recruiting investigator will impact on the long-term management and outcome of a participant with CF**
3. Previous growth of PsA from respiratory culture
4. Infants with a history of hypersensitivity to ß-lactam antibiotics (e.g. penicillins) or excipients
5. Infants with a history of flucloxacillin associated jaundice/hepatic dysfunction

*Infants with an inconclusive diagnosis after NBS (termed ‘CF Screen Positive Inconclusive Diagnosis (CFSPID)’) should not receive standard CF care and should not be recruited into CF START (Munck et al 2015).
The two situations that result in a diagnosis of CFSPID after NBS are
1. Two CFTR mutations recognised, one or both of which are not characterised as CF-causing and the sweat chloride is less than 30 mmol/L
2. The sweat chloride is repeatedly between 30-59 mmol/L and only one or no CFTR mutations are recognised

**Significant non-CF conditions might include chromosomal abnormality (for example, Down syndrome), cerebral palsy, chronic lung disease (oxygen requirement) following pre-term birth and other significant congenital anomalies (for example, severe cardiac disease, tracheo-oesophageal fistula, diaphragmatic hernia).