1. These authors contributed equally to this article and share first authorship
2. Department of Public Health HSE-South, St. Finbarr’s Hospital, Cork, Ireland
3. Health Protection Surveillance Centre, Dublin, Ireland
4. European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control, (ECDC), Stockholm, Sweden
5. Department of Public Health HSE-South, Tralee, Kerry, Ireland
6. National Virus Reference Laboratory, University College Dublin, Dublin 4, Ireland
7. Department of Public Health HSE Mid-West, Mount Kennett House, Limerick, Ireland
8. Department of Public Health HSE-East, Dr. Steevens' Hospital, Dublin 8, Ireland