Clinical Efficacy of Stopping Oral Antibiotics When Symptoms Stop, Compared to 'Finishing the Course'

The aim of the StopStop@HITH study is to see if stopping antibiotics when symptoms stop is as good as finishing the course of antibiotics. The study will enrol children at the Royal Children's Hospital who are prescribed oral antibiotics after completing a course of intravenous (IV) antibiotics for the treatment of cellulitis, urinary tract infection (UTI), lower respiratory tract infection (LRTI) and lymphadenitis. The aims of the study are: * To determine if oral antibiotics can be safely stopped once symptoms stop in children with cellulitis (who have completed a course of IV antibiotics). * To assess feasibility of a larger study of other common infections across multiple hospitals. The participants parent/guardian will complete a daily symptom tracker for the duration of the prescribed oral antibiotic course and attend a telehealth appointment with the study team once the participants symptoms have resolved. There are additional follow up surveys at day 14, day 28 and day 180.

This is a single-centre, basket, randomised controlled trial (RCT). There are four baskets in the trial related to infection type - cellulitis (basket 1), urinary tract infection (UTI) (basket 2), lower respiratory tract infection (LRTI) (basket 3) and lymphadenitis (basket 4). The primary objective (related to non-inferiority of efficacy) will be evaluated in children with cellulitis (basket 1) and the trial is powered for this objective. Secondary objectives related to feasibility will be evaluated in baskets 2-4 and will be used to inform a larger multi-site RCT to evaluate efficacy in these populations. Children admitted to the Royal Children's Hospital (RCH) who are initially treated with IV antibiotics will be enrolled, and will then be switched to oral antibiotics to complete treatment for their infection. In all baskets, children in intervention arms will stop antibiotics when symptoms stop, children in control arms will finish their course of antibiotics as prescribed as standard of care. Recruitment will start with patients on the Hospital in the Home (HITH) program, and progress to including patients from inpatient wards who will be monitored through the clinical governance of HITH.

Inclusion Criteria: 1. Between the ages of ≥ 1 years and ≤ 17 years at enrolment 2. Diagnosis of cellulitis, urinary tract infection (UTI), lower respiratory tract infection (LRTI) or lymphadenitis 3. Prescription of oral antibiotics as a switch from IV antibiotics Exclusion Criteria: 1. Clinician determined need for \>10-day oral antibiotic course 2. Child with immunosuppression (e.g. as a result of cancer treatment) 3. Second episode of same bacterial infection within the last 28 days 4. Child is unable to take oral antibiotics 5. Previous enrolment in StopStop@HITH 6. Parent/guardian does not speak English 7. Clinician determined need for 10-day course of oral antibiotics for treatment/clearance of streptococcal infection 8. UTI only: known impaired renal function (e.g. renal transplant patients or known chronic renal failure) 9. LRTI only: known chronic respiratory condition (e.g. cystic fibrosis or bronchiectasis) or need for long term respiratory support (e.g. home oxygen, Continuous Positive Airway Pressure \[CPAP\] or tracheostomy); empyema or lung abscess