Giardia:The disease giardiasis  is  caused by  the 'flagellated protozoan  Giardia larnblia.This disease occurs in the areas where poor sanitary conditions prevail and it affects mostly children. The cyst of this organism is absorbed through the intestinal walls and the affected person excretes Giardia cysts  in  faeces.

The  cysts get transferred  to  food when contaminated water  is used for washing  the vegetables. Consumption  of such  food containing  the  cysts leads  to  infection. The incubation period ranges between 2-25 days and  the symptoms include discomfort, rlausea  and diarrhoea. Infected persons  may  simply  be  the  carriers and  may  not always exhibit symptoms. The disease can be prevented by  adopting good personal habits and proper faecal disposal methods and protecting the water supplies from jaecal contamination.