Mary Mallon, known as "Typhoid Mary", was an asymptomatic carrier of "Salmonella" "enterica", the causative agent of typhoid fever. She worked as a cook for several families in New York City at the beginning of the twentieth century and she also cooked for the soldiers. Several cases of typhoid fever in members of those families were traced to her by the Health Department. It appeared that she "carried" the infectious agent without becoming sick. At the time, there was no way of eradicating the disease.