The first human cases of Cyclospora infection were reported in the 1970s, Wenman said. It is known now that Cyclospora is endemic in many parts of the world, and it appears to be an important cause of traveler's diarrhea. Cyclospora are two to three times larger than Cryptosporidium , but otherwise have similar features. People who are immunosuppressed may require longer courses of TMP-SMX therapy. In people with healthy immune systems, cryptosporidial diarrhea resolves on its own, Wenman said.
Posttreatment relapses are common.
Some researchers have been experimenting with a combination of paromomycin and macrolides. The first human cases of cryptosporidial diarrhea were not reported until the mid-1970s. At the time, people thought of cryptosporidial infections as exotic. Between 1976 and 1982, fewer than a dozen cases of cryptosporidial diarrhea were reported in the literature, she said. They occurred mostly in immunocompromised patients, such as in children with leukemia.