[Giardia lamblia as a rare cause of reactive arthritis].

Giardiasis is a disease of gut, which is caused by the non-invasive (it does not pass the gut/blood barrier) protozoan parasite Giardia lamblia. It infects humans and animals like beavers, dogs and cattle. Contaminated water or uncooked food is a major source of transmission and G. lamblia occurs worldwide. High-risk groups are young children, travellers and immunocompromised individuals. Good hand hygiene is necessary to prevent the transmission.