Cryptosporidium parvum: From foal to veterinary students.

This paper describes the transmission of a zoonotic subtype of Cryptosporidium parvum between two foals hospitalized in an Equine Perinatology Unit (EPU) linked to an outbreak of cryptosporidiosis in veterinary students. Fecal specimens of 36 mares (105 samples) and 28 foals (122 samples) were subjected to Ziehl-Neelsen staining, nested PCR of 18S rDNA. Two foals tested positive for Cryptosporidium; PCR restriction fragment length polymorphism (PCR-RFLP) analysis and subtyping by nested PCR of the 60kDa glycoprotein (gp60) gene revealed C. parvum subtype IIdA23G1. The introduction of Cryptosporidium into the EPU is suspected to be in a foal showing no initial clinical signs that tested positive for C. parvum during an asymptomatic phase. A second foal, hospitalized afterwards for perinatal asphyxia syndrome complicated with failure of passive transfer and sepsis, showed severe watery diarrhea after 4 days of hospitalization and was positive for the same subtype. During this period, six students attending the EPU complained of abdominal pain and diarrhea and were positive for the same subtype of C. parvum. To the authors' knowledge, this is the first description of this subtype in foals and the first report of evidence of zoonotic transmission of cryptosporidiosis from foals to human.