Shanghai, People’s Republic of ChinaCryptosporidiosis, microsporidiosis, giardiasis and cyclos-

poriasis are emerging infectious diseases. Cryptosporidium spp., Enterocytozoon spp., Giardia spp. and Cyclospora spp. are diarrhea-causing intestinal protozoans of humans (especially in AIDS patients), livestock and wildlife world-wide [1-4]. Although they are considered opportunistic gency responses among humans and animals [5-9] These four parasites pose significant challenges to public health and water authorities, especially in developing countries because of the high prevalence and disease burden of the infections [10,11]. Furthermore, they exert negative pres-sure on the growth and cognitive functions of infected chil-dren and immunocompromised persons [1,12,13]. Cryptosporidium and microsporidia infect AIDS or immunodeficient patients, travelers, children and the elderly. C. parvum and C. hominis are the main human-pathogenic Cryptosporidium species, while C. muris an