Article ID Journal Published Year Pages File Type
5793241 Preventive Veterinary Medicine 2015 8 Pages PDF
Abstract

•Adult susceptibility and dual-path infections were added to a model of MAP.•Infection in high-path animals progressed more quickly than previously believed.•Adult susceptibility can decrease the likelihood of MAP elimination on a farm.•Fast-progressing high-path animals increase MAP persistence on a farm.•Elimination of MAP from a dairy farm using a test-and-cull program is unlikely.

Models of Mycobacterium avium subsp. paratuberculosis (MAP), a chronic infectious agent of cattle, are used to identify effective control programs. However, new biological findings show that adult infections occur and that infected animals can be separated into 2 paths: animals that will become high-shedding and, eventually, experience clinical disease (high-path); and animals that will shed only small quantities of MAP and will remain subclinical (low-path). Longitudinal data analysis found that high-path animals progress more quickly than previously believed. A standard model of MAP transmission in dairy herds was modified to include adult low-path infections and 2 infection pathways for infected calves. Analysis of this model showed that adult infection may play an important role in MAP dynamics on a dairy farm, and that the increased rate of progression for high-path animals influences both the prevalence and the persistence of MAP on a dairy farm. This new model will be able to determine the effectiveness of MAP control programs more accurately than previous models.

Related Topics
Life Sciences Agricultural and Biological Sciences Animal Science and Zoology
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