Cryptosporidiosis Clinical Presentation

Updated: Jan 13, 2022
  • Author: Maria A Caravedo, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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After an incubation period of 5-10 days (range 2-28 days), an infected individual develops watery diarrhea, which may be associated with abdominal cramps. [1, 26, 46, 47]   In sporadic cases, fever may be low grade or nonexistent; however, during outbreaks, fever may occur in 30%-60% of patients.

Diarrhea, with or without crampy abdominal pain, may be intermittent and scant, or continuous, watery, and copious; sometimes, the diarrhea is mucoid. It rarely contains blood or leukocytes. In individuals who are immunocompetent, the median duration of diarrhea ranges from 5-10 days (mean of 10 days). Relapses may follow a diarrhea-free period of several days to weeks. Diarrhea can persist longer in individuals who are immunosuppressed.

The clinical manifestations of cryptosporidiosis in patients with HIV vary. [1, 34, 48]  In patients with CD4 cell counts of more than 200/µL, most infections are self-limited, similar to those in healthy hosts. Other patients develop chronic diarrheal illness with frequent, foul-smelling, bulky stools associated with significant weight loss. A minority of patients develop a profuse, cholera-like diarrhea that can be complicated by malabsorption and volume depletion. The volume of fluid losses through diarrhea may be extremely high, particularly in individuals with AIDS and CD4 cell counts below 50 cells/μL.

Biliary tract involvement is seen in persons with AIDS who have very low CD4 cell counts and is common in children with X-linked immunodeficiency with hyper–immunoglobulin M (IgM). Biliary involvement may include acalculous cholecystitis, sclerosing cholangitis, papillary stenosis, or pancreatitis. All are associated with right upper quadrant pain, nausea, and vomiting. [1, 42, 43]

Although the main symptoms of cryptosporidiosis are related to the gastrointestinal (GI) tract, in immunocompromised patients, respiratory symptoms may also develop. Respiratory tract involvement is often asymptomatic, but it may manifest as bilateral pulmonary infiltrates with dyspnea. Nonspecific respiratory symptoms, including shortness of breath, wheezing, cough, hoarseness, and croup, may be manifestations of respiratory infection. Rarely, conjunctival irritation is also present.

In waterborne outbreaks, immunocompetent patients present with subclinical or milder illness that lasts for less than 5 days.


Physical Examination

Physical findings are nonspecific. Temperature higher than 39°C is not characteristic of cryptosporidiosis and warrants investigation for other infections. The patient may have signs of volume depletion or wasting from malabsorption.

Other signs related to GI illness include right upper-quadrant or epigastric tenderness, icterus, and, rarely, ascites related to pancreatic involvement. Reactive arthritis that affects the hands, knees, ankles, and feet has been described.