Use of a voluntary testing program to study the spatial epidemiology of Johne?s disease affecting dairy herds in Minnesota: a cross sectional study
Investigation article published in BMC Veterinary Research
December 2nd, 2019
One of the key steps in the management of chronic diseases in animals including Johne’s disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), is the ability to track disease incidence over space and time. JD surveillance in the U.S. dairy cattle is challenging due to lack of regulatory requirements, imperfect diagnostic tests, and associated expenses, including time and labor. An alternative approach is to use voluntary testing programs. Here, data from a voluntary JD testing program, conducted by the Minnesota Dairy Herd Improvement Association, were used to: a) explore whether such a program provides representative information on JD-prevalence in Minnesota dairy herds, b) estimate JD distribution, and, c) identify herd and environmental factors associated with finding JD-positive cows. Milk samples (n = 70,809) collected from 54,652 unique cows from 600 Minnesota dairy herds between November 2014 and April 2017 were tested using a MAP antibody ELISA. Participant representativeness was assessed by comparing the number of JD-tested herds with the number of herds required to estimate the true disease prevalence per county based on official statistics from the National Agricultural Statistical Services. Multivariable logistic regression models, with and without spatial dependence between observations, were then used to investigate the association between herd status to JD (positive/negative), as indicated by milk ELISA results, and available covariates at the herd level
Kanankege KST., Machado G., Zhang L., Dokkebakken B., Schumann V., Wells SJ., Perez AM. and Alvarez J..
 | Department of Veterinary Population Medicine. College of Veterinary Medicine. University of Minnesota (UMM). |
 | Department of Population Health and Pathobiology. College of Veterinary Medicine. North Carolina State University (NCSU). |
| Division of Biostatistics. School of Public Health. University of Minnesota (UMM). |
 | Minnesota Dairy Herd Improvement Association. |
 | Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
| Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM). |
