Life cycle Gardia Intestinalis

Question 1

What is the classification of Gardia Intestinalis?

Answer 1

Protozoa in the category of flagellates

Question 2

How is Gardia Intestinalis transmitted?

Answer 2

Stool and contaminated food or water

Question 3

What are the steps of the Gardia Intestinalis lifecycle in the human host?

Answer 3

1. Cyst gets swallowed via for example contaminated food or water
2. When the cysts are swallowed they pass through the esophagus and stomach into the small intestine
3. In the small intestine each cyst releases 2 trophozoites through a process called excystation
4. The Giardia cyst feeds of and absorbs nutrients from the host
5. Trophozoites multiply by splitting in two through binary fission. This is asexual reproduction. This happens remaining in the small intestine so they can be free or attached to the wall of the small intestine.
6. Trophozoites move towards the colon and transform back into cyst through a process called encystation. This stage is found mostly in stool.
7. Cysts get excreted through stool

Question 4

What are the lifecycle steps of Gardia Intestinalis lifecycle outside of the human host?

Answer 4

8.Cysts are immediately infectious once they leave the body and can survive for several months in soil and cold water.

Question 5

What type of life cycle does Gardia Intestinalis have?

Answer 5

Direct life cycle. Human is the intermediate host

Question 6

What are the symptoms of Gardia Intestinalis infection?

Answer 6

Asymptomatic in most cases
Symptoms in small children and people with immune system deficiency
Diarrhea symptoms often accompanied by gas, nausea and abdominal cramps
Chronic symptoms: Weight loss, general malaise and fatigue

Question 7

Where is Gardia Intestinalis endemic?

Answer 7

Everywhere. It is seasonal in the Netherlands in august, September and October

Question 8

How is Gardia Intestinalis diagnosed?

Answer 8

Triple feces test: feces from 3 days to check for cysts or trophozoites under a microscope.

Elisa: test for presents of antigen. Uses feces again

Biopsy of small intestine tissue: biopsy, only done if other tests can’t detect but there is a strong suspicion of infection

PCR (real time & multiplex): Multiplex can be used to test for other parasites at the same time.