Physical and Biological Hazards of the Workplace, 3rd Edition

Chapter 26PARASITES

William N. Yang

CRYPTOSPORIDIUM PARVUM

Common names for disease: Cryptosporidiosis

Many species of Cryptosporidium exist that infect humans and a wide range of animals. Although Cryptosporidium parvum, found in young cattle and other herbivores, and Cryptosporidium hominis, the human-adapted species, (formerly known as C. parvum anthroponotic genotype or genotype 1) are the most prevalent species causing disease in humans, infections by Cryptosporidium felis, Cryptosporidium meleagridis, Cryptosporidium canis, and Cryptosporidium muris have also been reported.¹

Occupational setting

Farmers, animal handlers, veterinarians, laboratory personnel, healthcare workers, daycare workers, and divers are at risk from exposure.^1–4

Exposure (route)

Human cryptosporidiosis was first reported in 1976. Its characteristics are having a very low infectious dose (10–1000 oocysts), being severe in immunocompromised populations, being very resistant to antiparasitic therapy, and having human and nonhuman reservoirs. Cryptosporidiosis is most common in developing countries, with waterborne, foodborne, person-to-person, and zoonotic transmission pathways. It still remains a significant pathogen of children and the elderly in industrialized nations and can cause major outbreaks when public health measures break down. It is a common cause of wasting and lethal diarrhea in HIV-infected persons, and acute and persistent disease among farmers, animal handlers, and veterinarians ...