1. Health Service Executive, Health Protection Surveillance Centre, Dublin, Ireland
2. These authors contributed equally to this manuscript
3. Department of Health, Dublin, Ireland
4. Mater Private Hospital, Dublin, Ireland
5. Children’s University Hospital Temple Street, Dublin, Ireland
6. Cork University Hospital, Cork, Ireland
7. Health Service Executive, Health Intelligence Unit, Dublin, Ireland
8. Our Lady’s Children’s Hospital, Crumlin, Dublin, Ireland