The mystery of typhoid fever was uncovered in Oyster Bay with a woman now known as Typhoid Mary.

According to historian Nicole Menchise, in the summer of 1906 a wealthy banker rented a home in Oyster Bay from the Thompson family. In August of that year, in a matter of a 10-day period, everyone in the house came down with typhoid fever. Everyone was treated and survived the deadly disease, but when the Thompsons returned to their home, they were concerned about what was brought into it.

Menchise says the Nassau County Department of Health investigated the outbreak, but found no cause. "But Mr Thompson was not ready to drop the case because it was his home and his reputation, and you can imagine what a stir that caused here in Oyster Bay," says Menchise.

Thompson then hired an infectious specialist, Dr. George Soper, who determined the outbreak might have been caused by a person, not a type of food. It was that outbreak in Oyster Bay that lead to the discovery that a person can be a carrier of a disease without showing any symptoms.

Soper then narrowed his search down and found that a cook in the home, Mary Mallon, was a carrier. She was arrested and placed under quarantine in a small cottage at Riverside Hospital, on an island off of Manhattan. Years later, she is released and promised never to cook for the public again. However, she was caught cooking at a hospital for women, where a massive outbreak occurred. According to Menchise, Mallon was arrested again and quarantined at Riverside until she died.

It is unknown how many people were infected and died because of Mallon. According to Menchise, at least three deaths have been linked to her, with estimates running as high as 50 cases.