Age, geographic, and temporal distribution of fecal shedding of Cryptosporidium parvum oocysts in cow-calf herds.
Am J Vet Res
; 60(4): 420-5, 1999 Apr.
Article
in En
| MEDLINE
| ID: mdl-10211683
ABSTRACT
OBJECTIVE:
To evaluate fecal shedding of Cryptosporidium parvum from California cow-calf herds with respect to age, geographic region, temporal effects, and association with watery feces. ANIMALS Cows and calves from 38 beef cow-calf operations. PROCEDURE Fecal specimens were collected and examined for C parvum oocysts, using immunofluorescent microscopy. Associations between age, geographic region, month of collection, watery feces, and likelihood of shedding C parvum were evaluated.RESULTS:
3.9% of cattle were shedding C parvum oocysts. Prevalence of shedding among calves ranged from 0 to 13%, and was 0.6% among cattle > or = 12 months old. The odds of shedding C parvum among 2-month-old calves were 41 times greater than among cattle > 4 months old. The odds of shedding C parvum among cattle tested in May were 8.7 times greater than among cattle tested during June, July, or August. The odds of infected individuals having watery feces were 3 to 4 times greater than for noninfected individuals, but the etiologic fraction was only 8 to 9%. CONCLUSIONS AND CLINICAL RELEVANCE Substantial fecal shedding of C parvum by cow-calf herds was limited to calves 1 to 4 months old, with low prevalence detected in older animals. Risk of contamination of watersheds with C parvum was limited to those periods when young calves were in the herd. Although the odds of having watery feces were greater for animals infected with C parvum than for noninfected animals, the low etiologic fraction suggests that most calves with watery feces were not infected with C parvum.
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Collection:
01-internacional
Health context:
3_ND
Database:
MEDLINE
Main subject:
Cattle Diseases
/
Cryptosporidium parvum
/
Cryptosporidiosis
/
Feces
Type of study:
Risk_factors_studies
Limits:
Animals
Country/Region as subject:
America do norte
Language:
En
Journal:
Am J Vet Res
Year:
1999
Document type:
Article