The NVRL has a pivotal role in investigation and tracking of outbreaks of viral infection. A number of serological and molecular methodologies are available for outbreak analysis; The NVRL has been actively involved in the investigation of a number of outbreaks for Hepatitis A (3) Measles (4), Influenza (5), Norovirus (6), Adenovirus 8 (7) , HCV transmission (8) and also for the investigation of transmission events within hospital units. Protocols for such analyses include; Wide range of diagnostic serological and molecular methods Non-invasive investigation of viral infection using oral fluid samples Phylogenetic analysis of trends and case linkage Close interaction with the National Disease Surveillence Centre in the formulation of guidelines 1-2 Timely co-operation with Area Medical Officers and Department of Public Health Officials 1. Guidelines for the Control of Measles in Ireland: October 2002 2. National Guidelines on the management of outbreaks of Norovirus infection in healthcare settings: December 2003 3. Sayers G, Condon M, La Harpe D, Connell J, Dooley S. (1999): Hepatitis A outbreak in an institution. Irish Medical Journal 92: 396-398 4. Coughlan S, Connell J, Cohen B, Jin Li,, Hall WW (2002). Suboptimal measles-mumps-rubella vaccination coverage facilitates an imported measles outbreak in Ireland. Clinical Infectious Diseases. 35. 84-6 5. Danis C, Fitzgerald M, Connell J, Conlon M, Murphy P. Lessons form a preseason influenza outbreak in a day school. Accepted for publication 2004: Communicable Disease and Public Health 6. Molecular Analysis of Noroviruses – Power point presentation – 7. Outbreak of Adenovirus type 8 infection – Virus Alert Issue 1, April 2004 8. Duffy M, Salemi M. Sheehy N. Vandamme AM, Hegarty J, Curry M, Nolan N, Kelleher D, McKiernan S, Hall WW. (2002). Comparative rates of nucleotide variation in the hypervariable region of E1/E2 and the NS5b region of Hepatitis C virus in patients with a spectrum of liver disease resulting from a common source of infection. Virology, 301. 354-64