Giardiasis Fact Sheet

Giardiasis is an intestinal infection caused by the parasite Giardia lamblia. It spreads through contaminated food, water, or direct contact with infected individuals. Symptoms include diarrhea, stomach cramps, bloating, and nausea. Proper hygiene and water safety can help prevent infection.

Causes and Transmission
  • Parasite: Caused by Giardia lamblia, which infects the intestines and disrupts digestion.
  • Contaminated Water and Food: The most common source is ingesting water or food contaminated with feces containing Giardia cysts.
  • Person-to-Person Spread: Direct contact with infected individuals, particularly in childcare settings, can spread the parasite.
  • Animal Transmission: Some animals can carry Giardia and contaminate water sources.
Symptoms of Giardiasis

The first signs of symptoms can appear from 3 to over 25 days after a person becomes infected.

  • Diarrhea: Watery, foul-smelling diarrhea is a hallmark symptom.
  • Stomach Cramps and Bloating: Abdominal discomfort and gas are common.
  • Nausea: May lead to loss of appetite and weight loss.
  • Fatigue: Persistent tiredness due to poor nutrient absorption.
  • Prolonged Symptoms: Some cases can last for weeks or become chronic.
Prevention
  • Safe Drinking Water: Use boiled, filtered, or treated water, especially when traveling.
  • Good Hygiene: Wash hands thoroughly with soap and water, particularly before eating and after using the toilet.
  • Proper Food Handling: Wash raw fruits and vegetables with clean water before eating.
  • Avoid Contaminated Water: Do not swallow water from lakes, rivers, or pools that may be contaminated.
Treatment of Giardiasis
  • Antiparasitic Medication: Prescription medications such as metronidazole or tinidazole effectively treat the infection.
  • Hydration: Replacing lost fluids is important, especially in cases of severe diarrhea.
  • Supportive Care: Rest and maintaining a balanced diet help recovery.
Giardiasis Around the World

Giardiasis is a common cause of waterborne illness worldwide. According to the Centers for Disease Control and Prevention (CDC), millions of cases occur annually, particularly in areas with poor water sanitation. Improved hygiene, access to clean water, and proper sanitation practices are key to reducing infections.

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