Giardia intestinalis

Giardia intestinalis is a cyst-forming, single-celled parasite of the genus Giardia (Lamblia).

Giardia intestinalis causes an infectious diarrheal disease (giardiasis) which can lead to the following disease patterns:

  • Gastroenteritis

  • Cholangitis (inflammation of the bile ducts)

  • Pancreatitis (inflammation of the pancreas)

Giardiasis intestinalis occurs in various animal species (beavers, voles, cattle, dogs, cats) as well as in humans.

Relevance of pathogen in transmission in endoscopy

  • Gastroenterology: High

  • Pulmonology: Not relevant

  • Ear, nose, and throat: Not relevant

  • Urology: Not relevant

Relevance for endoscope surveillance

  • Low or moderate concern organism

Transmission route

Giardia intestinalis is usually transmitted fecal-orally via contaminated food or contaminated drinking water. Cysts (resistant permanent forms) of the pathogen can remain infectious in (drinking) water for up to three months.

Resistance to antibiotics

A possible decreased susceptibility to nitroimidazoles is described.

Sources and further readings

  1. Giardiasis, Robert Koch-Institut, Accessed on 07.06.2021.

  2. Gries O, Ly T: Infektologie – Kompendium humanpathogener Infektionskrankheiten und Erreger, Springer-Verlag Berlin Heidelberg 2019.

  3. Mlekusch I. Parasitäre Durchfallerkrankungen: Selten, aber hartnäckig, Österreichische Ärzte-Zeitung, Nr. 9/2018.

  4. Parasites – Giardia, Centers for Disease Control and Prevention, Accessed on 07.07.2021.