It is a stomach bug known to afflict some backpackers with bouts of uncomfortable diarrhoea.
Now scientists say they have discovered how the parasites that cause giardiasis – one of the world’s most common gastric diseases – make people ill.
Giardia parasites mimic human cell functions to break apart cells in the gut and feed inside, researchers found.
This also allows bacteria already present in the body to join in and feed from the same nutrients, they said.
Some 500,000 cases of giardiasis are diagnosed each year, with people typically picking up the disease by drinking infected water or contaminated food.
Symptoms include severe diarrhoea, stomach pains, bloating, flatulence and fatigue and can last weeks or months without treatment.
Although it is found throughout the world, it is most prevalent in developing countries and is one of the most common gastric diseases caught by backpackers.
But although scientists have known of giardia’s existence for hundreds of years, until now it remained unclear how it makes people sick.
FoodWorld 