title: Estimated within-herd prevalence (WHP) of Mycobacterium avium subsp. paratuberculosis in a sample of Minnesota dairy herds using bacterial culture of pooled fecal samples.
abstract: The objective of this study was to describe the estimated within-herd prevalence (WHP) of Mycobacterium avium subsp. paratuberculosis (Map) in a sample of infected dairy herds in Minnesota (N = 66) using test results from bacterial culture of pooled fecal samples. Fecal samples were collected from up to 100 cows in each herd and were tested using bacterial culture in pools of 5 cows based on age order. The mean herd size was 222 (44 to 1500) milking cows; the cows were predominantly Holstein. Using a frequentist approach, the within-herd mean individual fecal prevalence was 10% [95% confidence interval (CI) = 4% to 16%] assuming 70% test sensitivity and 99.5% test specificity. Using Bayesian methods, the estimated true within-herd individual cow prevalence was 14% (95% CI = 7% to 27%). Within-herd prevalence was higher in larger dairy herds than in herds with fewer cows. As Map is the causative agent of Johne's disease (JD), the results of this study could contribute to the success of a nationwide control program for this disease.
authors: Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota 55108, USA. eraizman@purdue.edu
authors: Eran A
authors: EA
authors: Raizman
authors: Scott J
authors: SJ
authors: Wells
authors: Claudia A
authors: CA
authors: Muñoz-Zanzi
authors: Saraya
authors: S
authors: Tavornpanich
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000453:epidemiology*; D003612:Dairying; D005243:Feces / Q000382:microbiology*; D005260:Female; D008910:Minnesota / Q000453:epidemiology; D016927:Mycobacterium avium subsp. paratuberculosis / Q000302:isolation & purification*; D010283:Paratuberculosis / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012680:Sensitivity and Specificity