Giardiasis

Description

Giardiasis is a diarrheal illness caused by the protozoan Giardia intestinalis, which lives in the intestines of persons and animals and is passed in their feces. Transmission occurs from ingestion of fecally contaminated food or drinking water, swallowing recreational water, from exposure to fecally contaminated environmental surfaces, and from person to person by the fecal-oral route.

Occurrence

Giardiasis occurs worldwide.

Risk for Travelers

Risk of infection increases with duration of travel and is highest for those who live in or visit rural areas, trek in backcountry areas, or frequently eat or drink in areas that have poor sanitation and inadequate drinking water treatment facilities.

Clinical Presentation

Symptoms occur approximately 1–2 weeks after ingestion of the parasite and include diarrhea, abdominal cramps, bloating, fatigue, weight loss, flatulence, anorexia, or nausea, in various combinations, and usually last >5 days and can become chronic resulting in malabsorbtion. Fever and vomiting are uncommon. The parasite is passed in the feces of an infected person or animal.

Prevention

No vaccine is available and there is no known chemoprophylaxis. To prevent infection, travelers to disease-endemic areas should be advised to follow the precautions included in the sections Risks from Food and Drink.

Treatment

Effective antimicrobial drugs are available, including metronidazole. Treatment recommendations are available in textbooks on internal medicine and infectious diseases; consultation with a travel or tropical medicine specialist can also be sought.

— Michael Beach