1. Ricardo A. Caicedo, M.D. Pediatric Gastroenterology
Giardia lamblia
Ricardo A. Caicedo, M.D.
Pediatric Gastroenterology

2. Giardia lamblia Intestinal parasite Widespread Flagellated protozoan
Small bowel
Adheres and divides
Growth stimulated by bile, carbohydrates
Causes malabsorption
Widespread
2nd most common parasitic infection in US
2.5 million cases/yr (CDC)

3. Giardiasis Risk factors Natural history Well water Daycare
Contaminated drinking water
Daycare
Recreational water
Swimming pools
Summer camp
Uncooked food
Immunodeficiency
Natural history
Gradual onset of diarrhea
Most become asymptomatic by 6 wks
Frequent re-infx
< 35%
Few develop prolonged diarrhea
weight loss
growth failure

4. Symptoms Malabsorption Abdominal distention Crampy abdominal pain
Watery, foul stools
Abdominal distention
Bloating, flatulence
Crampy abdominal pain
Malaise, weakness
Nausea/vomiting
Anorexia
weight loss

5. Giardiasis Diagnosis Treatment Stool antigen test (EIA)
Greater sensitivity than O+P
Sens: 90-99%
Spec: %
Simpler than duodenal biopsy
Often overlooked
Fever, WBC, eosinophilia rare
Treatment
Metronidazole 15 mg/kg/d X 10 d
albendazole
furazolidone
Asymptomatic carriers usually not treated