Retrospective assessment of rapid outbreak investigation for gastrointestinal diseases using only cases and background exposure data

Kafatos, G., Mook, P., Charlett, A., Rees, E. , Elson, R., Inns, T., Kanagarajah, S. and Andrews, N. J. (2020) Retrospective assessment of rapid outbreak investigation for gastrointestinal diseases using only cases and background exposure data. Epidemiology and Infection, 148, e60. (doi: 10.1017/s0950268820000527)

Abstract

For outbreaks of gastrointestinal disease, rapid identification of the source is crucial to enable public health intervention and prevent further cases. Outbreak investigation comprises analyses of exposure information from cases and, if required, undertaking analytical epidemiological studies. Hypothesis generation has been reliant on empirical knowledge of exposures historically associated with a given pathogen. Epidemiology studies are resource-intensive and prone to bias, one of the reasons being the difficulties in recruiting appropriate controls. For this paper, the information from cases was compared against pre-defined background exposure information. As exemplars, three past outbreaks were used, one of common and two of rare exposures. Information from historical case trawling questionnaires was used to define background exposure having removed any exposures implicated with the outbreak. The case-background approach showed good sensitivity and specificity, identifying correctly all outbreak-related exposures. One additional exposure related to a retailer was identified and four food items where all cases had been exposed. In conclusion, the case-background method, a development of the case-case design, can be used to assist with hypothesis generation or when a case-control study may not be possible to carry out.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Rees, Dr Eleanor
• Authors: Kafatos, G., Mook, P., Charlett, A., Rees, E., Elson, R., Inns, T., Kanagarajah, S., and Andrews, N. J.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Epidemiology and Infection
• Publisher: Cambridge University Press (CUP)
• ISSN: 1469-4409
• ISSN (Online): 1469-4409
• Published Online: 21 February 2020
• Copyright Holders: © Crown Copyright, 2020
• First Published: First published in Epidemiology and Infection 148:e60
• Publisher Policy: Reproduced under a Creative Commons license