Prevalence of Mycobacterium avium subsp. paratuberculosis Fecal Shedding in Alpacas Presented to Veterinary Hospitals in the United States
Article first published online: 19 JUN 2013
Copyright © 2013 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 27, Issue 5, pages 1228–1233, September/October 2013
How to Cite
Fecteau, M.-E., Bedenice, D., Cebra, C.K., Pinn, T.L., McAdams, S.C., Fyock, T.L., Whitlock, R.H. and Sweeney, R.W. (2013), Prevalence of Mycobacterium avium subsp. paratuberculosis Fecal Shedding in Alpacas Presented to Veterinary Hospitals in the United States. Journal of Veterinary Internal Medicine, 27: 1228–1233. doi: 10.1111/jvim.12125
- Issue published online: 13 SEP 2013
- Article first published online: 19 JUN 2013
- Manuscript Accepted: 8 MAY 2013
- Manuscript Revised: 5 APR 2013
- Manuscript Received: 5 SEP 2012
- University of Pennsylvania, School of Veterinary Medicine
- Alpaca Research Foundation
- American Association of Veterinary Laboratory Diagnosticians
- Infectious diseases
The prevalence of Johne's disease in alpacas in the United States is unknown. The limits of polymerase chain reaction (PCR) detection of Mycobacterium avium subsp. paratuberculosis (MAP) in alpaca feces have not been determined.
To evaluate the use of PCR for MAP detection in alpaca feces; and to estimate the prevalence of MAP fecal shedding in alpacas presented to veterinary teaching hospitals.
Alpacas presenting to 4 US veterinary teaching hospitals from November 2009 to February 2011.
Prospective study. Ten dilutions of a wild MAP strain were added to negative alpaca feces and processed for MAP detection by means of a commercial real-time PCR (RT-PCR) assay, and cultured on Herrold's Egg Yolk Medium (HEYM) and liquid broth. The limits of detection for each method were determined. Fecal samples from alpacas admitted to the veterinary teaching hospitals during the study period were evaluated for MAP via PCR and HEYM.
The lowest MAP dilution detectable via PCR was 243 MAP colony-forming units (CFU)/g of feces, at which concentration MAP growth was detectable on HEYM. Ten (6%; 95% confidence interval: 3–9%) of the 180 fecal samples collected were positive on PCR.
Conclusions and Clinical Importance
Polymerase chain reaction can provide an accurate and rapid detection of MAP fecal shedding in alpacas; and the prevalence of MAP fecal shedding in hospitalized alpacas in 4 US veterinary teaching hospitals was 6%.