Supplemental File S2: Typhoid Mary case
The Case of Typhoid Mary
In the early 1900s, Mary Mallon worked as a cook in New York. At that time, she was known for her peach melba; today she is best known for her ability to spread typhoid fever. Known as “Typhoid Mary”, she has been credited with starting seven epidemics and infecting more than 50 people within a 10 year period. In 1907, she was sentenced to live in an isolated cottage on Brother Island, New York. In 1910, she was released after agreeing to not work as a cook again. However, Mary did take more cooking jobs and continued to cause outbreaks of typhoid including one in a hospital that infected 25 people and killed two. She was tracked down in 1915 while she was working under an assumed name. She was returned to Brother Island and lived out her remaining 23 years in relative isolation. Mary died in 1938 at the age of 69.
In the United States today, there are approximately 5700 cases of typhoid/year; most of these are acquired during international travel. In contrast, typhoid remains a significant health concern in the developing world where about 21 million people/year are affected. The etiologic agent of typhoid is Salmonella enterica subtype Typhi (S. Typhi). Found only in humans, S. Typhi is a Gram-negative motile rod. After ingestion of contaminated food or water, S. Typhi survives passage through the stomach to reach the intestines and establish infection. Infected people carry S. Typhi in their blood and intestine; it is shed via feces. S. Typhi is transmitted to a susceptible host by ingestion of contaminated food or water. Mary Mallon was a lifelong carrier of S. Typhi. While she reported never having typhoid, she shed S. Typhi in her feces until she died.
Approximately 1-2 weeks after ingestion symptoms will appear. During the 1st week, the symptoms are somewhat general--headache, fever, general malaise. Definitive diagnosis can be made by testing blood or stool for S. Typhi. During this stage, patients may feel exhausted and experience a loss of appetite. During the second week, the fever may rise to 104∘F. Patients may experience delirium and about 10% of patients develop a rose-colored rash. The abdomen may become distended; diarrhea or constipation is associated with this stage of infection. Without treatment, the infection will grow more severe and can lead to intestinal perforation and hemorrhage; death occurs in about 20% of cases. Typhoid can be treated with antibiotics and there is a vaccine available. Typhoid can be treated with antibiotics; without treatments, the illness can last 3-4 weeks and death may occur.
Image credits:
General Research Division, The New York Public Library. "Typhoid Mary." New York Public Library Digital Collections. Accessed June 5, 2015.
S. Typhi image: Public Health Image Library #16877
1) Mary Mallon caused 7 epidemics during her lifetime. What is an epidemic? How does it differ from a pandemic or endemic disease?
2) In this case, what was the reservoir of disease?
3) Mary’s job as a cook facilitated transmission of the typhoid to others. The transmission of typhoid via food represents what mode of transmission? What would be the portal of entry? What was the portal of exit?
4) S. typhi produces a variety of adhesins including multiple types of fimbriae. Why are adhesins important in pathogenesis?
5) What is the relationship between the terms pathogenicity and virulence?
6) Like all pathogens, S. typhi produces a variety of virulence factors during infection. What are virulence factors? Provide 2 general examples of virulence factors.
7)Draw a graph showing the course of the disease and the relative number of S. typhi over time. Label the five stages of the disease on your graph. Hint: the case provides you information about the progression of the disease—use this to guide you!
After listening to the RadioLab story and reading the NY Times article, answer the following:
8) Describe George Soper’s approach in determining the cause of the typhoid outbreaks. A flow chart of his steps might be an effective way to approach this.
9) What type of epidemiological study was Soper conducting?
10) How does the work that Soper was doing differ from etiology?
11) Based on the RadioLab piece, you know that Mary was not the only person that was identified as a carrier in New York. So why was Mary the only one quarantined on Brother Island? Why is she the only one that we talk about today? Judith Leavitt, author of Typhoid Mary and guest in the RadioLab piece, thinks that there was prejudice against Mary for being Irish and a woman, and also for being a domestic servant, not having a family, not being considered a "bread earner," having a temper, and not believing in her carrier status. What do you think? Pay attention to the historical context—we are talking about events that occurred in the early 1900’s, not the present day.
Sources:
Leavitt, J.W. 1996.Typhoid Mary: Captive to the Public's Health. Beacon Press, Boston, MA.
Bourdain, A. 2001. Typhoid Mary: An Urban Historical. Bloomsbury, New York, NY.