Evaluation of periparturient dairy cows and contact surfaces as a reservoir of Cryptosporidium parvum for calfhood infection.
OBJECTIVE
To determine whether periparturient cows or contact surfaces to which newborn calves are exposed are reservoirs of Cryptosporidium parvum oocysts.


METHODS
Periparturient cows and their calves.


METHODS
Using direct fluorescent antibody (DFA) and acid-fast (AF) assays, fecal samples taken before and after calving from periparturient cows were tested for C parvum oocysts. Fecal samples from calves were collected every other day from age 7 to 21 days and were tested by use of the AF assay. Topsoil from close-up and maternity pens and scrapings from wooden walls and floors of calf hutches were tested for C parvum oocysts by use of DFA assay.


RESULTS
None of the 384 fecal samples obtained 1 to 21 days before or after calving or on the day of calving from 154 periparturient cows contained detectable C parvum oocysts. Despite this lack of detectable periparturient shedding, the period prevalence of calfhood infection was 92% (123/134) from age 7 to 21 days. Soil samples from the close-up and maternity pens where newborn calves spend the first 12 hours of life also were negative for C parvum oocysts. Wood scrap ings from the outer 2 mm of the walls and floors of empty and cleaned calf hutches that were ready to receive calves were C parvum oocyst-positive.


CONCLUSIONS
Conditional on sensitivity of DFA, periparturient cows did not appear to shed detectable C parvum oocysts. In contrast, the floors and walls of wooden calf hutches contained detectable C parvum oocysts on the surface.
Atwill
E R
ER
Veterinary Medicine Teaching and Research Center, School of Veterinary Medicine, University of California, Davis, Tulare, CA 93274, USA.
Harp
J A
JA
Jones
T
T
Jardon
P W
PW
Checel
S
S
Zylstra
M
M
D000818:Animals; D000831:Animals, Newborn / Q000469:parasitology*; D002140:California / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology*; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D016785:Cryptosporidium parvum; D004197:Disease Reservoirs / Q000662:veterinary*; D005243:Feces / Q000469:parasitology; D019085:Fluorescent Antibody Technique, Direct / Q000662:veterinary; D010270:Parasite Egg Count / Q000662:veterinary; D015995:Prevalence; D013499:Surface Properties