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Giardiasis: Treatment and prevention

Luther A Bartelt, MD
Section Editors
Peter F Weller, MD, MACP
Sheldon L Kaplan, MD
Deputy Editor
Elinor L Baron, MD, DTMH


Giardia lamblia (also known as Giardia duodenalis or Giardia intestinalis) is a flagellated protozoan parasite [1]. G. lamblia causes both epidemic and sporadic disease; it is an important etiology of waterborne and foodborne diarrhea and daycare center outbreaks [2-4].

Issues related to the treatment and prevention of giardiasis will be reviewed here. The life cycle, epidemiology, clinical manifestations, and diagnosis of giardiasis are discussed separately. (See "Giardiasis: Epidemiology, clinical manifestations, and diagnosis".)


Initial approach

Nonpregnant adults and children — The approach to treatment of symptomatic individuals with giardiasis includes antimicrobial therapy and supportive care (eg, correction of fluid and electrolyte abnormalities resulting from the diarrhea). (See "Clinical assessment and diagnosis of hypovolemia (dehydration) in children" and "Treatment of hypovolemia (dehydration) in children" and "Oral rehydration therapy".)

In general, administration of antimicrobial therapy for treatment of symptomatic individuals with giardiasis is appropriate. However, some infections are self-limited, and it is reasonable to forgo treatment for patients with mild symptoms and/or contraindications to antimicrobial therapy. (See 'Pregnant and lactating women' below.)

Symptoms of giardiasis include diarrhea, malaise, steatorrhea, abdominal cramps, bloating, flatulence, and nausea. In patients with chronic infection, diarrhea may not be a predominant symptom. In young children, symptoms may also include weight loss and failure to thrive. Symptoms of giardiasis are discussed further separately. (See "Giardiasis: Epidemiology, clinical manifestations, and diagnosis", section on 'Clinical manifestations'.)

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Literature review current through: Nov 2017. | This topic last updated: Nov 30, 2017.
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