In general, the mortality rate for infected AIDS patients is based on CD4+ marker counts. Patients with CD4+ counts over 180 cells/mm³ recover with supportive hospital care and medication; but, in patients with CD4+ counts below 50 cells/mm³, the effects are usually fatal within 3 to 6 months. During the Milwaukee cryptosporidiosis epidemic (the largest of its kind), 73% of AIDS patients with CD4+ counts lower than 50 cells/mm³ and 36% of those with counts between 50 and 200 cells/mm³ died within the first year of contracting the infection.The best treatment approach is to improve the immune status in immunodeficient individuals using highly active antiretroviral therapy that includes an HIV protease inhibitor along with continued use of antiparasitic medication. Antiparasitic drug treatment for immunocompromised individuals usually involves the combination of nitazoxanide, paromomycin, and azithromycin together; these drugs are only partially active in HIV/AIDS patients compared to their effect in immunocompetent persons. A Cochrane Collaboration review recommended that nitazoxanide be considered for use in treatment despite its reduced effectiveness in immunocompromised individuals.Currently, research is being done in molecular-based immunotherapy. For example, synthetic isoflavone derivates have been shown to fight off Cryptosporidium parvum both in vitro and in animal studies. Derivates of nitazoxanide, known as thiazolides, have also shown promising results in vitro. rifaximin is also sometimes used for immunocompromised patients/patients with severe disease. Epidemiology
Cryptosporidiosis is found worldwide. It causes 50.8% of water-borne diseases that are attributed to parasites. In developing countries, 8–19% of diarrheal diseases can be attributed to Cryptosporidium.
The source of the Cryptosporidium is believed to be overflow from the Milwaukee area combined sanitary and storm sewer system into Lake Michigan, which was then taken into the Howard Avenue Water Purification Plant and distributed to an estimated 880,000 residents (of the 1.61 million residents in the Milwaukee area who receive their drinking water from Lake Michigan). These residents, who receive their drinking water from Lake Michigan, were told to boil their water before drinking it. More people were affected in this one outbreak than the combined number of people affected in every cryptosporidiosis outbreak in the 24 years since then. An estimated 69 people died during the outbreak, according to the CDC. The UKs biggest outbreak occurred in Torbay in Devon in 1995. In the summer of 1996, Cryptosporidium affected approximately 2,000 people in Cranbrook, British Columbia, Canada. Weeks later, a separate incident occurred in Kelowna, British Columbia, where 10,000 to 15,000 people got sick. 2001–2009
In April 2001, an outbreak occurred in the city of North Battleford, Saskatchewan, Canada. Between 5800 and 7100 people had diarrheal illness, and 1907 cases of cryptosporidiosis were confirmed. Equipment failures at the citys antiquated water filtration plant following maintenance were found to have caused the outbreak. In the summer of 2005, after numerous reports by patrons of gastrointestinal upset, a water park at Seneca Lake State Park, in the Finger Lakes region of upstate New York was found to have two water storage tanks infected with Cryptosporidium.