Epidemiology of Giardia Lamblia / Giardia Intestinalis

• It is a worldwide infection and is one of the most common intestinal infections in US


• It has a high prevalence rate among young children in third world countries, and in places with untreated water and poor sanitation system


• It is highly infectious, and as few as 10 cysts can cause an infection in an individual


• Route of transmission includes waterborne transmission, ingestion of contaminated food, fecal-oral route, person-to-person contact, and sexual transmission.


• Enhanced susceptibility to giardiasis is associated with blood group A, achlorrhydria, use of cannabis, chronic pancreatitis, malnutrition & immune defects (eg. 19A deficiency & hypogammaglobulinaemia)


• Naturally infect cats, dogs, cattles, sheeps & many wild animals


• Giardia species infecting birds, amphibians & mice can be differentiated from G.lamblia by morphological features