Cryptosporidium is a genus of protozoans that infect humans and other animal hosts, and frequently cause enteritis and associated diarrhea. These parasitic microorganisms also infect the lungs. Most infections of humans are attributed to C. hominis and C. parvum, but C. canis, C. felis and C. meleagridis, which usually infect dogs, cats and birds, respectively, are also zoonotic. Cryptosporidium cuniculus was originally detected in rabbits and has been identified as an emerging human pathogen. 300 rabbits were reported to have died from cryptosporidiosis. To date, C. cuniculus has been found exclusively in rabbits and humans and is genetically closely related to C. hominis and C. parvum, and has been responsible for outbreaks of cryptosporidiosis in humans. The infection's source was water.
Since the first UK outbreak of cryptosporidiosis, there has been increasing interest in C. cuniculus due to the zoonotic threat that it poses.1 The parasite has a complex life cycle that includes both asexual and sexual stages. While there are invasive free living stages, spreading and differentiation take place within a unique vacuole under the host cell brush border but outside the host cell cytoplasm. Infection is spread by environmentally resistant spores that primarily contaminate drinking water and occasionally food sources, which may cause significant outbreaks of diarrhea that generally lasts less than 2 weeks in otherwise healthy individuals. Although diagnosis is relatively simple, effective drug treatment, particulary for infections in immunodeficient patients, has not been uniformly successful.2
Rabbits are particularly susceptible to C. parvum which is closely related to C. hominis (human parasite). Therefore, there is a risk that humans can be infected with C. parvum. It would be necessary to take precautions when handling pet rabbits with diarrhea. Both pet and wild rabbits are a potential source of human cryptosporidiosis and as such, good hygiene practices are recommended during and after handling rabbits or exposure to their feces, or potentially contaminated surfaces. Water supplies should be protected against access by wildlife, including rabbits.