We all remember when Martin Shkreli, CEO of Turing Pharmaceuticals raised the price of Daraphim from twenty dollars a tablet to seven hundred and fifty dollars a tablet. Shkreli's defense was that the drug is used very rarely, and he had to charge a lot to make a profit. To editorialize, it almost seemed like Shkreli was excusing his actions because "only 300 people in the country have this disease," this disease being toxoplasmosis.

He's not wrong, toxoplasmosis is very uncommon. It's almost exclusively contracted by people with severely weakened immune systems, such as those suffering from end-stage AIDS, chemotherapy, and people who have recently received organ transplants.