In the fall of 1940, the German army rounded up Jewish people in Warsaw, Poland, and restricted them to a scant 1.3 square mile area. This become known as the Warsaw Ghetto, where 400,000 people were forced to live in a density more than ten times that of New York City. How does one fight disease in such conditions?
German officials knew enough about the spread of typhus to know that by overcrowding, starving and depriving the Jewish residents of basic necessities, the ghetto would become a breeding ground for infection. Additional food supplies were blocked until May 1941, at which point rations provided by authorities amounted to no more than 200 calories per day, per person. The starvation made fighting any disease that did emerge near impossible, and louse vectors spread easily due to a lack of adequate sanitation and an abundance of hosts.
More than 100,000 Jews were infected by typhus and at least 25,000 died directly from it. But, just before the winter of 1941, as an epidemic in the ghetto was breaking out, something remarkable happened: cases dropped exponentially when they should have continued to rise.
A new study of data from health records, diaries, and other archives from the ghetto show how Jewish doctors led a public health campaign that used what little they had to combat typhus: information. That included not only managing the inhabitants of the ghetto, but also running a clandestine medical school and lying to the Germans. Read about the fight against typhus in the Warsaw Ghetto at Smithsonian.