An epidemiological study of Cryptosporidium parvum in two herds of adult beef cattle.
Prevalences of Cryptosporidium parvum oocysts in faeces and of isotype-specific anti-C. parvum antibodies in serum of apparently healthy adult cattle on two farms were determined. On Farm 1 cryptosporidial diarrhoea had been recorded in more than 80% of calves born over the previous 5 years, whereas on Farm 2 cryptosporidiosis had never been reported. No differences were demonstrated in oocyst excretion or presence of antibodies between the two farms. C. parvum oocysts were detected in 62.4% of faecal smears collected from a total of 553 apparently healthy adult cattle. Sucrose flotation was performed on a proportion of the faecal samples. This proved a more sensitive technique, detecting oocysts in 92% of the samples tested, and highlighting the insensitivity of direct smears for detecting oocysts. More than 90% of the cattle had specific anti-C. parvum IgG, IgG1, IgG2 and IgM antibodies and 58% specific anti-C. parvum IgA antibodies. Results suggest that asymptomatic adults may play an important role in the epidemiology of cryptosporidiosis in calves.
Scott
C A
CA
Department of Veterinary Medicine, Glasgow University Veterinary School, Bearsden, UK.
Smith
H V
HV
Mtambo
M M
MM
Gibbs
H A
HA
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002417:Cattle / Q000469:parasitology*; D002418:Cattle Diseases / Q000453:epidemiology* / Q000276:immunology / Q000469:parasitology; D003457:Cryptosporidiosis / Q000453:epidemiology* / Q000276:immunology / Q000469:parasitology; D016785:Cryptosporidium parvum / Q000276:immunology / Q000302:isolation & purification; D004812:Epidemiologic Methods / Q000662:veterinary; D005243:Feces / Q000469:parasitology; D005260:Female; D005455:Fluorescent Antibody Technique; D008297:Male
D000913:Antibodies, Protozoan