Abstract

Cryptosporidium spp. has emerged as an important cause of diarrheal disease in humans and animals, with a global distribution. The epidemiology of cryptosporidiosis is complex, and transmission occurs through both direct (human-tohuman, animal-to-human) and indirect (through water and food) routes. In humans, the majority of infections are caused by C. hominis and C. parvum, but a number of other species have been recognized as human pathogens. The burden of disease is particularly high among young children in developing regions of the world, where cryptosporidiosis is one of the major causes of moderate-to-severe diarrhea and is associated with an increased risk of death. In developed countries, contamination of drinking water has caused several large waterborne outbreaks. Effective drug treatments and vaccines are not yet available, but the partial immunity after exposure suggests the potential for developing vaccines. Routine diagnostic methods for Cryptosporidium often have a low sensitivity, and those based on antigen or DNA detection, that greatly improve sensitivity, are underused. Recent advances in nextgeneration sequencing techniques will significantly improve our knowledge of the transmission of Cryptosporidium. However, increased funding will be essential to combat this important pathogen.