The Where is Norovirus Control Lost (WINCL) Study: an enhanced surveillance project to identify norovirus index cases in care settings in the UK and Ireland. Issue 1 (January 2016)

• Record Type: Journal Article
• Authors: Curran, Evonne T; Wilson, Jennie; Haig, Caroline E; McCowan, Colin; Leanord, Alistair; Loveday, Heather
• Is Part Of: Journal of infection prevention. Volume 17:Issue 1(2016:Jan.)
• Page Start: 8
• Page End: 14
• Publication Date: 2016-01
• Subjects: Norovirus -- outbreaks -- index case -- care setting; Hospital buildings -- Sanitation -- Periodicals; Communicable diseases -- Prevention -- Periodicals; Nosocomial infections -- Prevention -- Periodicals; Cross infection -- Prevention -- Periodicals; 616.9045
• DOI: 10.1177/1757177415613133
• Languages: English
• ISSNs: 1757-1774

Abstract

Background: Norovirus outbreaks have a significant impact on all care settings; little is known about the index cases from whom these outbreaks initiate. Aim: To identify and categorise norovirus outbreak index cases in care settings. Methods: A mixed-methods, multi-centre, prospective, enhanced surveillance study identified and categorised index cases in acute and non-acute care settings. Results: From 54 participating centres, 537 outbreaks were reported (November 2013 to April 2014): 383 (71.3%) in acute care facilities (ACF); 115 (21.4%) in residential or care homes (RCH) and 39 (7.3%) in other care settings (OCS). Index cases were identified in 424 (79%) outbreaks. Of the 245 index cases who were asymptomatic on admission and not transferred within/into the care setting, 123 (50%) had been an inpatient/resident for 4 days. Four themes emerged: missing the diagnosis, care service under pressure, delay in outbreak control measures and patient/resident location and proximity. Conclusion: The true index case is commonly not identified as the cause of a norovirus outbreak with at least 50% of index cases being misclassified. Unrecognised norovirus cross-transmission occurs frequently suggesting that either Standard Infection Control Precautions (SICPs) are being insufficiently well applied, and or SICPs are themselves are insufficient to prevent outbreaks.