Clinical Features:

• "The spectrum varies from asymptomatic carriage to severe diarrhea and malabsorption. 

• Acute giardiasis develops after an incubation period of 5 to 6 days and usually lasts 1 to 3 weeks.  

• Symptoms include;

  •  Diarrhea

  •  Abdominal pain

  •  Bloating

  •  Nausea

  •  vomiting. 

•  In chronic giardiasis the symptoms are recurrent and malabsorption and debilitation may occur."

Laboratory Diagnosis:

• "Giardiasis is diagnosed by the identification of cysts or trophozoites in the feces, using direct mounts as well as concentration procedures. 

• Repeated samplings may be necessary. 

• In addition, samples of duodenal fluid (e.g., Enterotest) or duodenal biopsy may demonstrate trophozoites. 

• Alternate methods for detection include antigen detection tests by enzyme immunoassays, and detection of parasites by immunofluorescence. 

  • Both methods are available in commercial kits."

Treatment:

• The Medical Letter recommends metronidazole (Flagyl) as the drug of choice, with tinidazole, furazolidone, and paromomycin as alternatives.

courtesy of the Division of Parasitic Diseases at the National Center for Infectious Diseases, Centers for Disease Control & Prevention