Giardia intestinalis is a flagellated parasite and is regarded as the most common cause of protozoan-associated diarrhoea worldwide. The organisms can be found in 80% of raw water supplies from lakes, streams and ponds and as many as 15% filtered water samples. Giardia intestinalis can be found worldwide including both temperate and tropical regions and can cause asymptomatic colonisation or acute or chronic diarrhoea illness. The symptoms vary from vague abdominal discomfort or severe abdominal pain, diarrhoea and weight loss. It is believed that these symptoms are a result of giardiasis-associated malabsorption syndrome, although the pathophysiology underlying intestinal disturbances remains incompletely understood. Interestingly, intestinal malabsorption is a result of epithelial dysfunction that shares similarities with those observed in other enteric disorders such as bacteria enteritis, Crohn’s disease and celiac disease. Numerous other mechanisms of intestinal malabsorption have been postulated such as immunologic reactions, altered gut motility and fluid hypersecretion via adenylate cyclase activity. In this chapter, we will go through each mechanism of malabsorption associated with giardiasis and the consequences of this to the patients.
Part of the book: Giardiasis