Friday Parasite #18: It May Look Like an Alien...

                  

But it’s really Giardia, the backpacker’s bane. It’s common, it’s global, and it’s microscopic (it’s a protist). If you drink water that contains its infective stage, chances are you’re in for several days of flatulence and diarrhea as the protist colonizes your small intestine.


For more information, see:
Ford, B. J. 2005. The discovery of Giardia. Microscope 53: 147-153.

Photo from the CDC.