Cryptosporidium

Cryptosporidium, sometimes 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), sometimes with a persistent cough (respiratory cryptosporidiosis). Treatment of gastrointestinal infection in humans involves fluid rehydration, electrolyte replacement, and management of any pain. For cryptosporidiosis, supportive treatment and symptom management are the primary treatments for immunocompetent individuals. Anti-diarrheal medication may be effective in slowing the rate of diarrhea, including Loperamide. Nitazoxanide is the only drug approved for the treatment of cryptosporidiosis in immunocompetent persons. Supplemental zinc may improve symptoms, 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 diarrhoea, sometimes with a persistent cough in immunocompetent hosts. 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. 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. 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.