Granulomatous amebic encephalitis (also known as the "brain-eating amoeba") can be treated with Colloidal Silver, 10 ppm concentration, 15ml x 4/day.
The nanoparticles of silver are sized in the range of 1 - 10 nanometers, making it smaller than viruses, and easily capable of passing the blood-brain barrier.
Silver is used to maintain the purity of drinking water on the Russian Space Station Mir, as the Russians aren't under the authority of the FDA, which itself is highly influenced by large pharmaceutical corporations. Ironically, Colloidal Silver of inferior grades were approved by the FDA and manufactured for clinical use until 1978. The FDA and Big Pharma are trying to shut down manufacturer of Colloidal Silver for the very reason it's capable of curing this otherwise untreatable disease - that CS kills all sorts of amoeba, and unregulated, could affect the ecology of otherwise stagnant water and have enlisted the help of the EPA towards that end.
The means by which colloidal silver works is that it "sticks" to the active sites of the enzymes that pathogens use to breach cell membranes, not *killing* the amoeba/viruses per se, but rendering them incapable of infecting cells. This is illustrated in Figure 3 of the linked article on Nanosilver Hydrosols and HIV-1. Note the before and after pictures - the bright spots are where the HIV-1 viruses' cell membrane breaching enzymes are located.