Active against Cryptosporidium parvum in vitro and in immunocompetent patients
Limited activity in severely immunocompromised hosts without immune recovery
Paromomycin mechanism
Non-absorbed aminoglycoside acting luminally
Inhibits ribosomal protein synthesis
Used as adjunct to ART in refractory HIV cases
Future and investigational therapies
Bumped kinase inhibitors and nitazoxanide analogues in development
Paediatric-specific formulations lacking globally
NITAX trial investigating nitazoxanide in HIV-infected adults with cryptosporidiosis
Prevention strategies
Water treatment improvements
Pool hygiene and exclusion policies
No approved vaccine currently available
Antibiotic stewardship note
Empiric antibiotics should not be used for watery diarrhea without identified cause
Risk of C difficile induction
Does not cover Cryptosporidium
Patient Discharge Instructions
copy discharge instructions
Cryptosporidiosis home care instructions
Fluids and diet
Drink oral rehydration solution or clear fluids in small sips frequently
Avoid dairy products until diarrhea resolves
BRAT diet or small frequent meals may improve tolerance
Avoid alcohol
Medications
Take nitazoxanide with food if prescribed
Complete the full course as directed
Loperamide as directed for symptom relief only if prescribed
Infection prevention
Wash hands thoroughly with soap and water after using the toilet
Alcohol-based hand sanitisers are NOT effective against Cryptosporidium oocysts
Soap and water required for oocyst removal
Avoid swimming in pools or recreational water for at least 2 weeks after diarrhea resolves
Oocysts are chlorine-resistant and can contaminate pools
Avoid preparing food for others while symptomatic
Household contacts should practice strict hand hygiene
Return to emergency department immediately for
Inability to keep any fluids down
Persistent vomiting
Bloody diarrhea
Severe abdominal pain or right upper quadrant pain
Fever persisting or worsening
Dizziness, fainting, or confusion
Very dark urine or not urinating
Rapid worsening of symptoms
Follow-up instructions
Immunocompetent patients: follow up with family doctor in 1 to 2 weeks if symptoms persist
HIV or immunocompromised patients: follow up with your specialist within 1 week
Stool retesting may be required if symptoms continue after completing treatment
Expected recovery
Immunocompetent patients typically recover within 2 to 3 weeks
Relapse after apparent recovery is common
Immunocompromised patients require immune reconstitution for durable cure
HIV patients who start or optimise ART usually improve as CD4 counts recover
References
Guidelines and key sources
Primary clinical guidelines
IDSA/HIVMA guidelines for prevention and treatment of opportunistic infections in adults and adolescents with HIV 2025
Benson C, Brooks J, Dhanireddy S, et al.
Infectious Diseases Society of America and Office of AIDS Research Advisory Council
DHHS paediatric OI guidelines 2025
Kapogiannis BG, Yates F, Li W, et al.
Guidelines for prevention and treatment of opportunistic infections in children with and exposed to HIV
IDSA clinical practice guidelines for diagnosis and management of infectious diarrhea 2017
Shane AL, Mody RK, Crump JA, et al.
Clinical Infectious Diseases
Key clinical references
Pyzocha N, Cuda A. Common Intestinal Parasites. American Family Physician. 2023
Clinical management reference for cryptosporidiosis in primary care and emergency settings
Chen XM, Keithly JS, Paya CV, LaRusso NF. Cryptosporidiosis. New England Journal of Medicine. 2002
Foundational review of pathophysiology and treatment
Checkley W, White AC, Jaganath D, et al. Review of the global burden, novel diagnostics, therapeutics, and vaccine targets for Cryptosporidium. Lancet Infectious Diseases. 2015
Cohn IS, Henrickson SE, Striepen B, Hunter CA. Immunity to Cryptosporidium: Lessons from acquired and primary immunodeficiencies. Journal of Immunology. 2022
Semenza JC, Ko AI. Waterborne diseases that are sensitive to climate variability and climate change. New England Journal of Medicine. 2023
Coding references
ICD-10 A07.2 cryptosporidiosis
SNOMED CT cryptosporidiosis disorder concept
FDA drug label nitazoxanide Alinia for cryptosporidiosis dosing
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.