There were various ways for a prisoner to be infected with the malaria pathogens. First, they could be bitten by an infected mosquito that had been bred in the laboratory of the experiment station. Second, cells from the salivary glands of infected mosquitos could be injected into or under the test subject’s skin. Third, test subjects could be injected with blood from other infected patients. This was the case for Anton Balcerek, who was injected with three cubic centimeters of blood from Felix Rurkiewicz. Rurkiewicz had received blood on January 3, 1945, from Josef Figiel, who in turn had been infected with the blood of a different prisoner on December 18, 1944. Doctors could use the malaria cards to trace long transmission paths via multiple people.