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Cryptosporidium spp. Biological Agent Reference Sheet (BARS)

Updated December 1, 2023
Disclaimer: Risk group, biosafety level, and all other precautions noted here are subject to change after a risk assessment by EHS.


Agent Type Risk Group Biosafety Level Animal Housing Biosafety Level
Parasite RG-2 BSL-2 ABSL-2

Agent Characteristics 

Risk Group: RG-2, associated with human disease, rarely serious; preventive or therapeutic interventions are often available. 

Agent Type: Parasite   

Description: Cryptosporidium “Crypto” is an intracellular apicomplexan parasite. The oocyst is the infectious form that resides in the environment. After entry into the vertebrate host, the oocyst leaves the oocyst form (excystation) and sporozoites are released. The latter forms target epithelial cells of the gastrointestinal or, in extremely rare cases, respiratory tract. Gastrointestinal infection with Cryptococcus can occur as result of aerosol exposure, and gastrointestinal symptoms last around 1-2 weeks in non-immunocompromised individuals. Within the epithelial cell, new schizogony and merogony develop. Male and female gametogonia also develop within the epithelial cell and upon fertilization, new oocysts are formed. The thick- walled oocyst is excreted from the host and the thin- walled oocyst perpetuates the infection in the host. Oocyst are infective upon excretion permitting direct fecal-oral transmission. Since oocysts are shed in fecal materials, they are frequently in the presence of other microbes which may be harmful to human or animal health. 

Host Range: Multiple species of Cryptosporidium infect both humans and animals.  

Host Shedding: Feces                                              Route of Exposure to Humans: Ingestion 

Infectious Dose: 132 oocysts                                  Incubation Period: 2-10 days, 7 days average

Health Hazards

Signs and symptoms of infection may include:

  • Flu-like symptoms (i.e. fever, headache, dehydration, weight loss, lethargy)
  • Gastrointestinal symptoms (i.e. loss of appetite, nausea, vomiting, diarrhea)

Immunizations: None available.                            Prophylaxis*: treatment with Nitazoxanide

*Formal medical advice is obtained during medical consultations with Cornell Health or primary healthcare provider as needed.

Agent Viability 

Survival Outside Host Disinfection Inactivation

Long term survival outside the host. Resistant to chlorine-based disinfection.  

6% Hydrogen peroxide with 20 minutes contact time. Cryptosporidium is resistant to chlorine-based disinfectants. 

6% hydrogen peroxide with 20 minutes of contact time

For more guidance on disinfection see: disinfectant selection.

Laboratory Hazards 

  • High energy-creating activities (centrifugation, sonication, high pressure systems, vortexing, tube cap popping) 
  • Handling of sharps (needles, scalpels, microtome blades, broken glass, etc.) 
  • Splash/droplet-creating activities (shaking incubators, liquid culturing, mechanical pipetting) 
  • Equipment contamination
  • Exposed skin/uncovered wounds 

Laboratory Acquired Infection (LAI) History: multiple LAIs reported, numerous outbreaks among veterinary students.

Laboratory Handling Guidelines 

Laboratory Biosafety Level (BSL): BSL-2

Training Lab Engineering Controls Personal Protective Equipment
  • EHS Laboratory Safety Training (CULearn #2555)

  • Lab-specific protocol training 

  • Closed toed shoes and long pants 

  • Single gloves 

  • Additional gloves (recommended)

  • Snap front lab coat with cinch cuffs

Waste Management: Regulated Medical Waste (RMW)

Shipping Guidance: Refer to EHS Biological Materials Shipping 

BSL-2 Containment Requirements Summary

Animal Vivarium Guidance

Animal Housing Biosafety Level (ABSL): ABSL-2

Animal Biosecurity: Experimental animals are housed separately 

Perform Inoculations: Using Biosafety Cabinet (BSC)

Change Cages: Using Cage Changing Stations and a Biosafety Cabinet (BSC)

Exposure and Spill Procedures 

Mucous Membranes: Flush eyes, mouth, or nose for 15 minutes at an eyewash station. See: responding to exposures.

Other Exposures: Wash with soap and water for 15 minutes (open wounds, sores, etc.) or a minimum of 20 seconds for areas with intact skin. 

Small Spills: Notify others working in the lab. Don appropriate PPE. For spills involving fecal material, cover area of the spill with paper towels, working from the perimeter toward the center, use the paper towels to remove the spill and associated organic material. Discard contaminated paper towels. For spills involving fecal material and all other spills apply (or re-apply) 6% hydrogen peroxide on the spill site, Allow 20 minutes of contact time. After 20 minutes use paper towels to remove the 6% hydrogen peroxide. See: spill cleanup.

Large Spills: Request assistance from the EHS Spill Team by calling CUPD dispatch. Call 911 from a campus phone or 607-255-1111 from a mobile phone.

Incident Reporting: Immediately report the incident to supervisor and complete the EHS online injury/illness report as soon as possible.

Medical Follow-Up:

  • For students, seek medical attention at Cornell Health or local primary care provider. Call Cornell Health at 607-255-5155 (24-hour phone consultation line) or a local urgent care. 
  • For faculty and staff, seek medical evaluation with a local primary care provider or urgent care. Cornell Health does not see employees for post-exposure care. 
  • Emergencies: Call 911 from a campus phone or 607-255-1111 from a mobile phone. 
Cornell EHS would like to thank Emory University for the use of their Biological Agent Reference Sheet (BARS) format and some content. 

More Information


  1. Barbee, S. L., D. J. Weber, M. D. Sobsey, and W. A. Rutala. 1999. “Inactivation of Cryptosporidium parvum Oocyst Infectivity by Disinfection and Sterilization Processes.” Gastrointestinal Endoscopy 49 (5): 605–11.
  2. Bogan, James E. 2018. “Disinfection Techniques for Cryptosporidium.” Journal of Dairy & Veterinary Sciences 7 (4): 1–3. 
  3. CDC. 2009. Biosafety in Microbiological and Biomedical Laboratories. Center for Disease Control and Prevention.
  4. Lee, MB, and EH Lee. 2007. “The Effectiveness of Hydrogen Peroxide Liquid or Gas Plasma on Protozoan Oocysts.” Can J Infect Dis Med Microbiol. 18 (4): 2007.
  5. Venczel, L V, M Arrowood, M Hurd, and M D Sobsey. 1997. “Inactivation of Cryptosporidium parvum Oocysts and Clostridium Perfringens Spores by a Mixed-Oxidant Disinfectant and by Free Chlorine.” Applied and Environmental Microbiology 63 (4): 1598–1601.
  6. Okhuysen, P C, W Jakubowski, H L Dupont, C R Sterling, C Wang, and C L Chappell. 1999. “Infectivity of Cryptosporidium Parvum in Healthy Adults with Pre-Existing Anti-C. Parvum Serum Immunoglobulin G.” The American Journal of Tropical Medicine and Hygiene 60 (1): 157–64.
  7. Wilkes, Graham, Norma J. Ruecker, Norman F. Neumann, Victor P J Gannon, Cassandra Jokinen, Mark Sunohara, Edward Topp, Katarina D M Pintar, Thomas A. Edge, and David R. Lapen. 2013. “Spatiotemporal Analysis of Cryptosporidium Species/Genotypes and Relationships with Other Zoonotic Pathogens in Surface Water from Mixed-Use Watersheds.” Applied and Environmental Microbiology 79 (2): 434–48.
  8. Cacciò, S M. 2005. “Molecular Epidemiology of Human Cryptosporidiosis.” Parassitologia 47 (2): 185–92.
  9. Drinkard, Lauren N, Ashlee Halbritter, Giang T Nguyen, Patricia L Sertich, Max King, Sallyann Bowman, Rebecca Huxta, and Mary Guagenti. 2015. “Notes from the Field: Outbreak of Cryptosporidiosis Among Veterinary Medicine Students--Philadelphia, Pennsylvania, February 2015.” MMWR. Morbidity and Mortality Weekly Report 64 (28): 773.
  10. Miron, D, J Kenes, and R Dagan. 1991. “Calves as a Source of an Outbreak of Cryptosporidiosis among Young Children in an Agricultural Closed Community.” The Pediatric Infectious Disease Journal 10 (6): 438–41.
  11. Gait, R., R. H. Soutar, M. Hanson, C. Fraser, and R. Chalmers. 2008. “Outbreak of Cryptosporidiosis among Veterinary Students.” Veterinary Record 162 (26): 843–45.
  12. Preiser, Gary, Lynda Preiser, and Leslie Madeo. 2003. “An Outbreak of Cryptosporidiosis among Veterinary Science Students Who Work with Calves.” Journal of the American College Health Association 51 (5): 213–15.
  13. Gait, R., R. H. Soutar, M. Hanson, C. Fraser, and R. Chalmers. 2008. “Outbreak of Cryptosporidiosis among Veterinary Students.” Veterinary Record 162 (26): 843–45.