A study of cryptosporidiosis in a cohort of neonatal calves.
During calving time on an experimental farm, 32 newborn calves were selected at random and monitored for infection with Cryptosporidium parvum for the first 30 days of their lives. The animals were fed pooled colostrum for 2-3 days after birth and housed in individual pens, which were washed daily using a pressure hose. Fecal smears were examined by microscopy after staining with carbol fuschin for visualization of oocysts. Oocyst shedding was scored semiquantitatively according to the average number of oocysts in 20 randomly selected fields at 1000x magnification. All the animals acquired the infection before 18 days of age. The period of maximum risk was between 9 and 12 days; 50% of the animals were infected by 9.4 days of age. It was found that the earlier the animals acquired the infection, the longer the patent period. Oocyst shedding, which did not always begin with the onset of diarrhea, lasted between 8 and 23 days (mean 12.4+/-3.3 days). Furthermore, fecal samples from 32 periparturient cows (within +/-7 days of giving birth) were filtered, concentrated and examined for oocysts using a fluorescent monoclonal antibody test, which revealed that six of the cows, although asymptomatic, were excreting C. parvum oocysts.
Castro-Hermida
José A
JA
Laboratorio de Parasitología, Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Santiago de Compostela, Avda. de Vigo s/n., Santiago de Compostela, 15782 La Coruña, Spain.
González-Losada
Yolanda A
YA
Mezo-Menéndez
Mercedes
M
Ares-Mazás
Elvira
E
D000818:Animals; D000831:Animals, Newborn; D000913:Antibodies, Protozoan / Q000032:analysis; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology*; D015331:Cohort Studies; D003457:Cryptosporidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D016785:Cryptosporidium parvum / Q000254:growth & development*; D005243:Feces / Q000469:parasitology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D008297:Male; D010270:Parasite Egg Count / Q000662:veterinary; D011247:Pregnancy; D015995:Prevalence; D013030:Spain / Q000453:epidemiology; D018709:Statistics, Nonparametric
D000913:Antibodies, Protozoan