PhD Oral Defense: Investigating Cryptosporidium parvum surface proteins as candidates for a vaccine against bovine cryptosporidiosis
PhD Oral Defense of Karine Sonzogni-Desautels, Institute of Parasitology.
Bovine cryptosporidiosis caused by Cryptosporidium parvum is frequent and ubiquitous in dairy farms worldwide. C. parvum-related severe diarrhea and mortality in newborn dairy calves account for serious impairment of health and important economic losses. No vaccine is available to prevent oocyst shedding in field conditions and no treatment is available to cure the infection in calves. Catchment contamination with oocysts is a concern because C. parvum is a zoonotic pathogen. Large waterborne outbreaks of cryptosporidiosis have been reported worldwide due to contamination of drinking and recreational water. Also, people in contact with infected calves such as farmers and veterinary students are particularly at risk of infection. Human cryptosporidiosis caused by C. hominis or C. parvum is life-threatening in young children in developing countries particularly in sub-Saharan Africa and south Asia; it is the second most frequent cause of moderate-to-severe diarrhea in infants and the third most frequent cause in toddlers in these countries. No vaccine is available to prevent human infection and therapeutic drugs are of limited value in the target population. The ultimate goal of this project was to develop a vaccine that could be used to immunize pregnant cows to passively transfer immunity to newborn dairy calves in colostrum.