Pathogenesis (development of disease)
Giardia lamblia is a protozoan (single-celled organism) that lives in the intestine of humans and occurs in a stable cyst or as a vegetatively active trophozoite (vegetative life stage adult protists (also called protoctists) are eukaryotic organisms that are now considered to belong to a separate kingdom of living organisms). Giardiasis is transmitted fecal-orally by direct contact. Infection is possible after ingestion of only a few cysts.
The cysts can remain infectious for up to three months in a moist environment.
Etiology (Causes)
Biographic causes
- Blood type – Individuals with blood type A are more likely to be affected by giardiasis.
Behavioral causes
- Poor hand hygiene
- Contact with contaminated drinking water
- Consumption of contaminated food
