ABSTRACT
The role of each transmission route in endemic areas is frequently unclear because of the expensive nature of epidemiologic investigations and the inability to differentiate Cryptosporidium species by conventional microscopy. The use of Molecular tools has made significant contributions to our understanding of the biology and epidemiology of Cryptosporidium species. The Cryptosporidium genotyping tool based on PCR-RFLP analysis of the small subunit rRNA gene currently used in the molecular epidemiology laboratory of the Division of Parasitic Diseases, Centers for Disease Control and Prevention, is shown in the appendix. Molecular epidemiologic studies of cryptosporidiosis are in infancy, but significant progress has been made toward better understanding of the transmission of cryptosporidiosis in humans and the public health significance of Cryptosporidium species from farm animals, companion animals, and wildlife. Cryptosporidium parvum is no longer considered a homogeneous species, and humans are known to be infected with other species in addition to C. parvum.
