Parasitology Research

, Volume 112, Issue 3, pp 1247–1254

Description of fecal shedding of Cryptosporidium parvum oocysts in experimentally challenged dairy calves

Authors

  • Jennifer A. Zambriski
    • Department of Animal ScienceCornell University
    • Department of Population Medicine and Diagnostic Sciences, c2-562 VMC, College of Veterinary MedicineCornell University
  • Dwight D. Bowman
    • Department of Microbiology and Immunology, c5-181 VMC, College of Veterinary MedicineCornell University
  • Mary L. Bellosa
    • Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell University
  • Alexandra J. Burton
    • Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell University
  • Thomas C. Linden
    • Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell University
  • Janice L. Liotta
    • Department of Microbiology and Immunology, College of Veterinary MedicineCornell University
  • Theresa L. Ollivett
    • Department of Clinical Sciences, Box 20, College of Veterinary MedicineCornell University
  • Leonardo Tondello-Martins
    • Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell University
  • Hussni O. Mohammed
    • Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell University
Original Paper

DOI: 10.1007/s00436-012-3258-2

Cite this article as:
Zambriski, J.A., Nydam, D.V., Bowman, D.D. et al. Parasitol Res (2013) 112: 1247. doi:10.1007/s00436-012-3258-2

Abstract

The objective was to describe the probability of Cryptosporidium parvum fecal oocyst shedding at different magnitudes of exposure, the pattern of fecal shedding over time, and factors affecting fecal shedding in dairy calves. Within the first 24 h of life, 36 calves were experimentally challenged with C. parvum oocysts at one of four possible magnitudes of oral exposure (1 × 103, 1 × 104, 1 × 105, and 1 × 106 oocysts), and 7 control calves were sham dosed. Fecal shedding occurred in 33 (91.7 %) experimentally challenged calves and in none of the control calves. There was a difference in the log-total number of oocysts counted per gram of feces dry weight among the four exposure groups; calves with the lowest magnitude of exposure (1 × 103 oocysts) shed less than the other three groups. At higher magnitudes of exposure, there was more variability in the range of fecal oocyst shedding. There was an inverse relationship between the log-total amount of oocysts counted per gram of feces dry weight and the number of days to the onset of fecal shedding per calf, i.e., the more time that elapsed to the onset of fecal shedding, the fewer oocysts that were shed. The pattern of fecal shedding over time for all calves shedding oocysts was curvilinear; the number of oocysts increased with time, reached a peak, and declined. Therefore, the dynamics of oocyst shedding can be influenced in part by limiting exposure among calves and delaying the onset of fecal oocyst shedding.

Copyright information

© Springer-Verlag Berlin Heidelberg 2013