Giardia are relatively frequent guests in the human body. According to Sshill, giardiasis in Germany is observed in 25-27% in children and 10% in adults; Bach in the Rhineland found giardiasis (L.) in 14.9% of 435 people examined by him (adults and children); Wetzl er believes that in Italy 10% of adults are infected with L. Kuznetsova examined 46 patients with a thin probe and she found L. 12 times, and Permyakova and Lande found L. in 11 of the 39 patients they examined.