Open AccessA Simple Incidence-Based Method to Avoid Misinterpretation of Bovine Tuberculosis Incidence Trends in Great Britain
Author(s) -
Isobel M. Blake,
Christl A. Donnelly
Publication year - 2014
Publication title -
plos currents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.282
H-Index - 49
ISSN - 2157-3999
DOI - 10.1371/currents.outbreaks.6fd216fc24317f2ce04a7c5705a30c69
Subject(s) - incidence (geometry) , tuberculosis , herd , medicine , environmental health , bovine tuberculosis , asymptomatic , demography , veterinary medicine , statistics , mycobacterium bovis , pathology , mycobacterium tuberculosis , mathematics , geometry , sociology
The incidence of bovine tuberculosis (TB) in Great Britain has generally been increasing in recent decades. Routine ante-mortem testing of cattle herds is required for disease surveillance and control, due to the asymptomatic nature of the infection. The Department for Environment, Food and Rural Affairs (Defra) publishes TB incidence trends as the percentage of officially TB-free (OTF) herds tested per month with OTF status withdrawn due to post-mortem evidence of infection. This method can result in artefactual fluctuations. We have previously demonstrated an alternative method, that distributes incidents equally over the period of risk, provides a more accurate representation of underlying risk. However, this method is complex and it may not be sufficiently straightforward for use in the national statistics. Here we present a simple incidence-based method that adjusts for the time between tests and show it can provide a reasonable representation of the underlying risk without artefactual fluctuations.