You have to be pretty desperate to seek an organ donation

and in many cases, it comes out as a miracle cure. And then there's this sort of thing...

Brain Amoebas. Organ Transplants. Brrr.

The CDC’s weekly bulletin today describes that nightmare scenario come true. Last year, four people received the kidneys, heart and liver of a 4-year-old boy who died in Mississippi of encephalitis that was assumed to be a rare reaction to flu infection. Weeks after the transplant, the two kidney recipients developed neurological symptoms — spasms, seizures, visual disturbances — and were hauled back to hospitals for evaluation. MRIs showed ring-shaped lesions in both their brains. That sent investigators back to re-examine the boy’s death — and revealed that while he did have encephalitis, it wasn’t because of flu.

It was because he was infected with a newly recognized pathogen, Balamuthia mandrillaris, a species of amoeba. It had passed to the four recipients via his organs, and grew in them with an assist from the immune-suppressing drugs they were taking to prevent rejection.

First of all, the deaths and illnesses of recipients were the only real clues that anything was wrong. Two clusters are described in the article, with a total of five people dying (including the two donors). The only real treatment was to put the others on a regimen of drugs that includes one not available in the US except under direst emergency.

This shows that 1) any time you deal with human tissue--even tissue that's been carefully scruitinised--you run the risk of passing along a pathogen, because the possibilities, while not quite endless, are there, although in practice it's thankfully rare that something fatal gets through, 2) there are pathogens we know very little about and don't occur much (this one has only been found in about 200 human cases), so they don't get studied much, and 3) there's just something terrifying about an organism that you know so little about that the authorities THINK it might be caught from inhaling amoeba cysts in dust. Yeah. Breathe in. It's things like that that make us hypochondriacs insane. Oh, and the kicker? The little boy was from Kentucky and it's unclear as to whether he caught the amoebic infection here or in Mississippi. Yeah. They could be anywhere, hiding in dirt. Here's to hopefully strong constitutions.

Oh, and here's a nice fact from Wikipedia (which needs some updating in some areas of the article, but this was nicely attributed*):
'Balamuthia is most easily identifiable in a brain biopsy performed on an individual suffering from Balamuthia meningoencephalitis. The amoeba cannot be cultured on an agar plate coated with gram-negative bacteria because unlike most amoeba, Balamuthia mandrillaris does not feed on bacteria. Instead the amoeba must be cultured on primate hepatic cells or human brain microvascular endothelial cells, or HBMECs, the cells that constitute the blood-brain barrier.'

Um. Am I reading that right? It eats brains cells? Well, I guess something other than zombies have to, but yuck!

*Martínez AJ, Visvesvara GS (March 2001). "Balamuthia mandrillaris infection". J. Med. Microbiol. 50 (3): 205–7. PMID 11232763.