''Cystoisospora'' is a genus of parasitic

alveolate The alveolates (meaning "pitted like a honeycomb") are a group of protists, considered a major clade and superphylum within Eukarya. They are currently grouped with the stramenopiles and Rhizaria among the protists with tubulocristate mitochon ...

s belonging to the

phylum In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature f ...

Apicomplexa The Apicomplexa (also called Apicomplexia) are a large phylum of parasitic alveolates. Most of them possess a unique form of organelle that comprises a type of non-photosynthetic plastid called an apicoplast, and an apical complex structure. T ...

Taxonomy

This genus was originally created by J. K. Frenkel in 1977. Its use was discontinued but was resurrected in 2005. This genus currently includes species that have

oocyst Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism i ...

s containing two sporocysts with four sporozoites in each without Stieda bodies. These species infect the enterocytes of mammals and are transmitted by the orofaecal route. DNA analysis has shown that this genus belongs to the family ''

Sarcocystidae The Sarcocystidae are a family of Apicomplexa associated with a variety of diseases in humans and other animals. Taxonomy Genera in this family include: * '' Besnoitia'' * ''Cystoisospora'' * ''Frenkelia'' * ''Nephroisospora'' * '' Neospora'' ...

''. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of this genus is ''

Cystoisospora felis ''Cystoisospora'' is a genus of parasitic alveolates belonging to the phylum Apicomplexa. Taxonomy This genus was originally created by J. K. Frenkel in 1977. Its use was discontinued but was resurrected in 2005. This genus currently includes sp ...

''.

Life cycle

This parasite has been isolated from

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

s and

raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the common raccoon to distinguish it from other species, is a mammal native to North America. It is the largest of the procyonid family, having a body length of , and a body weight of ...

s. ''C. belli'' has been isolated from immunosuppressed humans — particularly those with

HIV The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...

infection. These parasites normally infect the enterocytes of the small intestine and are spread by the orofaecal route. The definitive hosts are cats but other species including various species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

s may be infected. No further development occurs in these

paratenic In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' ( symbiont). The guest is typically provided with nourishment and shelter. Examples include ...

hosts and the parasites remain dormant until ingested by a definitive host.

Epidemiology

This genus has been recorded worldwide. ''C. felis'' and ''C. rivolta'' occur in up to 40% of cats in some tropical countries.

Clinical

Clinical signs include watery

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...

fever Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...

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 trimethoprim-sulfonamides with

clindamycin Clindamycin is an antibiotic medication used for the treatment of a number of bacterial infections, including osteomyelitis (bone) or joint infections, pelvic inflammatory disease, strep throat, pneumonia, acute otitis media (middle ear infec ...

toltrazuril Toltrazuril is a coccidiostat. See also * Clazuril * Diclazuril * Ponazuril Ponazuril ( INN), sold by Merial, Inc., now part of Boehringer Ingelheim, under the trade name Marquis® (15% w/w ponazuril), is a drug currently approved for the tre ...

for resistant strains.

Prevention

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.

References

{{Taxonbar, from=Q5201274 Apicomplexa genera