Cystoisospora is a genus of parasitic protozoa belonging to the phylum Apicomplexa.
A[1].
These parasites normally infect the entrocytes of the small intestine and are spread by the orofaecal route. The definitive hosts are cats but other species including various species of rodents may be infected. No further development occurs in these paratenic hosts and the parastites remain dormant until ingested by a definitive host.
This genus has been recorded worldwide[2]. C. felis and C. rivolta occur in up to 40% of cats in some tropical countries[3].
Clinical signs include include watery diarrhoea, vomiting, fever and weight loss. The diagnosis is made by microscopic examination of the stool. Distinguishing between the species of Cystoisospora is most easily done with PCR. This method can also be used to make the diagnosis.
Treatment is based on the association of trimethoprim-sulfonamides with clindamycin or toltrazuril for resistant forms[4].
Hygiene on the premises is important in prevention. Good litter tray hygiene is also critical in multi-cat households. Utensils, runs, cages and other implements should be steam-cleaned or washed in boiling water. Because of the importance of paratenic hosts such as cockroaches, insect control is critical.