It all started with a man so desperate to escape forced labor in Nazi Germany in 1941 that he considered cutting off his own arm. Instead, on a whim, his doctor in Poland stuck a needle in his arm, the man tested positive for the oft-deadly typhus, and he was quarantined at home without ever falling ill. It was the first time Stasiek Matulewicz tried this on a patient, and he went on to share the exciting news with another physician, Eugene Slawomir Lazowski. As Mental Floss reports, the Polish doctors had discovered—and for years kept secret from everyone they knew, including Lazowski's own wife—that a bacterium suspension called Proteus OX19 used in labs to test for typhus would, when injected directly into a patient, provide a false positive. Blood results showed typhus, but the patient didn't have it.
Years later, from his new home in the US, Lazowski went on to write that he was "fighting for life." Having seen the elderly shot in the streets and babies thrown from prams and stomped to death in German-occupied Poland, he did what he could in other ways to save lives, including secretly treating Jewish patients and passing info on to an unseen co-conspirator, codenamed Pliszka. The contained series of typhus epidemics he'd staged near the southern Polish village of Stalowa Wola has been estimated to have saved as many as 8,000 lives. If true, his work surpassed that of Oskar Schindler, per Mental Floss. Years later, Lazowski told his wife—who he eventually found out was Pliszka—that he'd staged the outbreaks. When he returned to that pocket of Poland at the turn of the century, he was greeted with a ceremonious homecoming. "It was not real typhus," he had to explain to one man of the epidemics. "It was my typhus." Read the gripping story here. (Read more typhus stories.)