Estimation of the sensitivity of environmental sampling for detection of Salmonella in commercial layer flocks post-introduction of national control programmes

A key element of national control programmes (NCPs) for Salmonella in commercial laying flocks, introduced across the European Union, is the identification of infected flocks and holdings through statutory sampling. It is therefore important to know the sensitivity of the sampling methods, in order...

Full description

Saved in:
Bibliographic Details
Published in:Epidemiology and infection 2014-05, Vol.142 (5), p.1061-1069
Main Authors: ARNOLD, M. E., MARTELLI, F., MCLAREN, I., DAVIES, R. H.
Format: Article
Language:English
Subjects:
Animals
Bacteriology
Bayes Theorem
Biological and medical sciences
Competent authority
Data sampling
Dust
Eggs - microbiology
Environmental Microbiology
Environmental Monitoring
Estimation methods
European Union
Farms
Feces - microbiology
Flocks
Fundamental and applied biological sciences. Psychology
Gastrointestinal Pathogens
Infections
Methods
Microbiology
Miscellaneous
Models, Biological
Original Papers
Ovaries
Poultry
Poultry - microbiology
Poultry Diseases - diagnosis
Poultry Diseases - microbiology
Proportions
Salmonella
Salmonella - isolation & purification
Salmonella Infections, Animal - diagnosis
Salmonella Infections, Animal - microbiology
Sampling methods
Sensitivity and Specificity
Survey methods
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A key element of national control programmes (NCPs) for Salmonella in commercial laying flocks, introduced across the European Union, is the identification of infected flocks and holdings through statutory sampling. It is therefore important to know the sensitivity of the sampling methods, in order to design effective and efficient surveillance for Salmonella. However, improved Salmonella control in response to the NCP may have influenced key factors that determine the sensitivity of the sampling methods used to detect Salmonella in NCPs. Therefore the aim of this study was to compare estimates of the sensitivity of the sampling methods using data collected before and after the introduction of the NCP, using Bayesian methods. There was a large reduction in the sensitivity of dust in non-cage flocks between the pre-NCP studies (81% of samples positive in positive flocks) and post-NCP studies (10% of samples positive in positive flocks), leading to the conclusion that sampling dust is not recommended for detection of Salmonella in non-cage flocks. However, cage dust (43% of samples positive in positive flocks) was found to be more sensitive than cage faeces (29% of samples positive in positive flocks). To have a high probability of detection, several NCP-style samples need to be used. For confirmation of Salmonella, five NCP faecal samples for cage flocks, and three NCP faecal boot swab samples for non-cage flocks would be required to have the equivalent sensitivity of the EU baseline survey method, which was estimated to have an 87% and 75% sensitivity to detect Salmonella at a 5% within-flock prevalence in cage and non-cage flocks, respectively.
ISSN:0950-2688
1469-4409
DOI:10.1017/S0950268813002173