N Ondrikova1,2, H E Clough3,4, N A Cunliffe3,5, M Iturriza-Gomara3,6, R Vivancos4,5,7, J P Harris3,5. 1. Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK. nikola.ondrikova@liverpool.ac.uk. 2. Institute for Risk & Uncertainty, University of Liverpool, Liverpool, UK. nikola.ondrikova@liverpool.ac.uk. 3. Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK. 4. NIHR Health Protection Unit in Gastrointestinal Infections, University of Liverpool, Liverpool, UK. 5. Public Health England, Liverpool, UK. 6. Centre for Vaccine Innovation and Access, PATH, Geneva, Switzerland. 7. NIHR Health Protection Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool, UK.
Abstract
BACKGROUND: Norovirus has a higher level of under-reporting in England compared to other intestinal infectious agents such as Campylobacter or Salmonella, despite being recognised as the most common cause of gastroenteritis globally. In England, this under-reporting is a consequence of the frequently mild/self-limiting nature of the disease, combined with the passive surveillance system for infectious diseases reporting. We investigated heterogeneity in passive surveillance system in order to improve understanding of differences in reporting and laboratory testing practices of norovirus in England. METHODS: The reporting patterns of norovirus relating to age and geographical region of England were investigated using a multivariate negative binomial model. Multiple model formulations were compared, and the best performing model was determined by proper scoring rules based on one-week-ahead predictions. The reporting patterns are represented by epidemic and endemic random intercepts; values close to one and less than one imply a lower number of reports than expected in the given region and age-group. RESULTS: The best performing model highlighted atypically large and small amounts of reporting by comparison with the average in England. Endemic random intercept varied from the lowest in East Midlands in those in the under 5 year age-group (0.36, CI 0.18-0.72) to the highest in the same age group in South West (3.00, CI 1.68-5.35) and Yorkshire & the Humber (2.93, CI 1.74-4.94). Reporting by age groups showed the highest variability in young children. CONCLUSION: We identified substantial variability in reporting patterns of norovirus by age and by region of England. Our findings highlight the importance of considering uncertainty in the design of forecasting tools for norovirus, and to inform the development of more targeted risk management approaches for norovirus disease.
BACKGROUND: Norovirus has a higher level of under-reporting in England compared to other intestinal infectious agents such as Campylobacter or Salmonella, despite being recognised as the most common cause of gastroenteritis globally. In England, this under-reporting is a consequence of the frequently mild/self-limiting nature of the disease, combined with the passive surveillance system for infectious diseases reporting. We investigated heterogeneity in passive surveillance system in order to improve understanding of differences in reporting and laboratory testing practices of norovirus in England. METHODS: The reporting patterns of norovirus relating to age and geographical region of England were investigated using a multivariate negative binomial model. Multiple model formulations were compared, and the best performing model was determined by proper scoring rules based on one-week-ahead predictions. The reporting patterns are represented by epidemic and endemic random intercepts; values close to one and less than one imply a lower number of reports than expected in the given region and age-group. RESULTS: The best performing model highlighted atypically large and small amounts of reporting by comparison with the average in England. Endemic random intercept varied from the lowest in East Midlands in those in the under 5 year age-group (0.36, CI 0.18-0.72) to the highest in the same age group in South West (3.00, CI 1.68-5.35) and Yorkshire & the Humber (2.93, CI 1.74-4.94). Reporting by age groups showed the highest variability in young children. CONCLUSION: We identified substantial variability in reporting patterns of norovirus by age and by region of England. Our findings highlight the importance of considering uncertainty in the design of forecasting tools for norovirus, and to inform the development of more targeted risk management approaches for norovirus disease.
Entities:
Keywords:
HHH4; Mixed-effects; Negative binomial; Norovirus; Public health surveillance; Underestimation
Authors: Clarence C Tam; Laura C Rodrigues; Laura Viviani; Julie P Dodds; Meirion R Evans; Paul R Hunter; Jim J Gray; Louise H Letley; Greta Rait; David S Tompkins; Sarah J O'Brien Journal: Gut Date: 2011-06-27 Impact factor: 23.059
Authors: Joël Mossong; Niel Hens; Mark Jit; Philippe Beutels; Kari Auranen; Rafael Mikolajczyk; Marco Massari; Stefania Salmaso; Gianpaolo Scalia Tomba; Jacco Wallinga; Janneke Heijne; Malgorzata Sadkowska-Todys; Magdalena Rosinska; W John Edmunds Journal: PLoS Med Date: 2008-03-25 Impact factor: 11.069