December 12 - Balamuthia mandrillaris

Normally, Balamuthia mandrillaris is a free-living amoeba, but on rare occasions, it has opportunistically become a parasite, with almost always fatal results. These single-celled organisms are thought to enter the body through either open wounds or perhaps inhalation and then they make their way to the brain, where they cause a disease condition called granulomatous amoebic encephalitis. Luckily cases of B. mandrillaris are extremely rare, but on the other hand, because they are rare, not much is known about their biology.

Image is from the CDC image library.