Cryptosporidium andersoni
Cryptosporidium bailey
Cryptosporidium bovis
Cryptosporidium cervine
Cryptosporidium canis
Cryptosporidium cuniculus
Cryptosporidium ducismarci
Cryptosporidium fayeri
Cryptosporidium felis
Cryptosporidium fragile
Cryptosporidium galli
Cryptosporidium hominis
Cryptosporidium marcopodum
Cryptosporidium meleagridis
Cryptosporidium molnari
Cryptosporidium muris
Cryptosporidium parvum
Cryptosporidium ryanae
Cryptosporidium saurophilum
Cryptosporidium serpentis
Cryptosporidium suis
Cryptosporidium ubiquitum
Cryptosporidium viatorum
Cryptosporidium wrairi
Cryptosporidium xiaoi
Cryptosporidium, sometimes informally called crypto, is a genus of apicomplexan parasitic alveolates that can cause a respiratory and gastrointestinal illness (cryptosporidiosis) that primarily involves watery diarrhea (intestinal cryptosporidiosis) with or without a persistent cough (respiratory cryptosporidiosis) in both immunocompetent and immunodeficient humans.[1][2]
Treatment of gastrointestinal infection in humans involves fluid rehydration, electrolyte replacement, and management of any pain. As of January 2015[update], nitazoxanide is the only drug approved for the treatment of cryptosporidiosis in immunocompetent hosts.[3] Supplemental zinc may improve symptoms,[3] particularly in recurrent or persistent infections or in others at risk for zinc deficiency. Cryptosporidium oocysts are 4–6 μm in diameter and exhibit partial acid-fast staining. They must be differentiated from other partially acid-fast organisms including Cyclospora cayetanensis.
Cryptosporidium causes cryptosporidiosis, an infection that may present as a diarrhoeal with or without a persistent cough in immunocompetent hosts.[1] Other apicomplexan pathogens include the malaria parasite Plasmodium and the toxoplasmosis parasite Toxoplasma. Unlike Plasmodium, which transmits via a mosquito vector, Cryptosporidium does not use an insect vector, and is capable of completing its lifecycle within a single host, resulting in cyst stages that are excreted in feces or through inhalation of coughed on fomites and are capable of transmission to a new host.[1][4][5]
A number of Cryptosporidium species infect mammals. In humans, the main causes of disease are C. parvum and C. hominis (previously C. parvum genotype 1). C. canis, C. felis, C. meleagridis, and C. muris can also cause disease in humans.[4]
Cryptosporidiosis is typically an acute, short-term infection, can be recurrent through reinfection in immunocompetent hosts, and become severe or life-threatening in immunocompromised individuals. In humans, it remains in the lower intestine and may remain for up to five weeks.[4] The parasite is transmitted by environmentally hardy cysts (oocysts) that, once ingested, exist in the small intestine and result in an infection of intestinal epithelial tissue.[4] Transmission by ingestion or inhalation of coughed on fomites is a second, less likely route of infection.[1]