What is giardiasis?
Giardiasis is a stomach and intestinal infection caused by a tiny parasite called Giardia. The infection affects the digestive system and often leads to diarrhea and stomach discomfort. People usually get giardiasis after swallowing contaminated food or water.
This infection can happen anywhere, but it is more common in places where water sanitation is poor. Campers, hikers, travelers, and young children in group settings may have a higher risk of exposure.
Giardiasis spreads when microscopic parasites enter the body through contaminated food, drinks, or surfaces. Common causes and risk factors include:
- Drinking untreated water from lakes, streams, or wells
- Eating contaminated food
- Poor handwashing habits
- Close contact with someone who is infected
- Traveling to areas with unsafe water supplies
- Spending time in childcare centers or crowded living spaces
Symptoms
Giardiasis symptoms can range from mild to severe. Some people carry the parasite without feeling sick, while others develop digestive problems that can last for days or weeks.
Common symptoms include:
- Watery diarrhea
- Greasy or foul-smelling stools
- Bloating
- Gas
- Nausea
- Stomach cramps
- Fatigue
- Loss of appetite
- Mild fever
Symptoms often begin about 1 to 2 weeks after exposure to the parasite.
How is it diagnosed?
Healthcare providers diagnose giardiasis by testing stool samples for signs of the parasite. Because Giardia may not appear in every sample, more than one test may be needed.
Your provider may also review your symptoms, travel history, and possible exposure to contaminated water or food.
How is it treated?
Treatment for giardiasis usually starts with staying hydrated and replacing fluids lost through diarrhea. Some mild infections improve on their own, but many people benefit from prescription antiparasitic medication.
Common medicines used to treat giardiasis include:
- Metronidazole
- Tinidazole
- Nitazoxanide
If symptoms are severe or prolonged, your provider may recommend additional care to help with dehydration or nutritional concerns. Most people recover fully with proper treatment.
