When viewing this topic in a different language, you may notice some differences in the way the content is structured, but it still reflects the latest evidence-based guidance.

Cryptosporidiosis

Last reviewed: 3 Nov 2023
Last updated: 09 Jul 2019

Summary

Definition

History and exam

Key diagnostic factors

  • diarrhea
More key diagnostic factors

Other diagnostic factors

  • abdominal pain
  • vomiting
  • loss of appetite
  • low-grade fever
  • loss of weight
  • right upper quadrant abdominal pain
  • jaundice
  • nasal discharge and facial pain
  • cough and dyspnea
Other diagnostic factors

Risk factors

  • contact with farm animals, especially calves and lambs
  • international travel
  • age: 3 years or younger
  • immune deficiency: T-cell-mediated
  • swimming and recreational water sports
  • drinking unfiltered water
  • toileting or changing diapers of young children
More risk factors

Diagnostic investigations

1st investigations to order

  • stool microscopy
  • Cryptosporidium antigen detection
More 1st investigations to order

Investigations to consider

  • ultrasound scan of the biliary tract
  • CT scan of the biliary tract
  • endoscopic retrograde cholangiopancreatography (ERCP)
  • polymerase chain reaction for Cryptosporidium DNA
  • polymerase chain reaction for Cryptosporidium species identification
More investigations to consider

Treatment algorithm

ACUTE

immunocompetent

immunocompromised

Contributors

Authors

Rachel M. Chalmers, BSc, PhD

Consultant Clinical Scientist/Honorary Professor

Director of UK Cryptosporidium Reference Unit

Public Health Wales Microbiology

Singleton Hospital

Swansea

UK

Disclosures

RMC is a member of the following boards: WHO Water Quality and Health Technical Advisory Group; the UK Standards for Microbiology Investigations Bacteriology Working Group; Public Health England Water Advisory Group and Gastro-Intestinal Leads Group; Wales Microbiology Standing Specialist Advisory Group. RMC has received grant funding from EU FP7 project "Aquavalens" and EFSA partnering grant project IMPACT and has undertaken contract research from UK Water Industry Research. RMC has received payments for lectures and reimbursement for conference travel and subsistence. RMC is an author of a number of references cited in this topic.

Angharad P. Davies, MA, MBBCh, MRCP, FRCPath, PhD

Clinical Associate Professor

College of Medicine

Swansea University

Swansea

UK

Disclosures

APD is an author of a number of references cited in this topic.

Peer reviewers

Beth Kirkpatrick, MD

Assistant Professor

Infectious Diseases

University of Vermont College of Medicine

Burlington

VT

Disclosures

BK declares that she has no competing interests.

Yann Meunier, MD

Director

Stanford Health Promotion Network

Stanford School of Medicine

Palo Alto

CA

Disclosures

YM declares that he has no competing interests.

  • Cryptosporidiosis images
  • Differentials

    • Acute diarrhea
    • Chronic diarrhea
    • Crohn disease
    More Differentials
  • Guidelines

    • Guidelines for the prevention and treatment of opportunistic infections in HIV-infected adults and adolescents
    • Guidelines for the prevention and treatment of opportunistic infections in HIV-exposed and HIV-infected children
    More Guidelines
  • Patient leaflets

    Diarrhea in adults

    Diarrhea in children

    More Patient leaflets
  • padlock-lockedLog in or subscribe to access all of BMJ Best Practice

Use of this content is subject to our disclaimer