Are We Like Typhoid Mary — The Notorious Asymptomatic Carrier?
Mary Mallon, one of the first named “healthy carriers” of an infectious disease, Salmonella typhi, better known as Typhoid, directly infected at least fifty people and killing three people. A healthy carrier, or asymptomatic carrier, is a person who does not show symptoms yet carries and may transmit a disease to others. Eighty-three years after her death, with the COVID-19 asymptomatic carriers contributing to the spread of the virus, the story of Mary relates to the “healthy carriers” of today.
Many parallels have been made between prior pandemics with the COVID-19 pandemic. But along with the parallels of death and uncertainty of a cure, is the parallel of how people like Mary responded to a call for containing the disease’s spread on a personal and community level. Mary had refused to change jobs or isolate herself until she was physically forced to by authorities. She worked as a domestic servant, cooking for wealthy families in New York City.
With health officials and infection specialists learning how to contain the pandemic today, that distinction is important in determining the right way to contain the spread so as to allow time to educate the public. With the understanding of how COVID-19 is spread to others, experts agree that the most consistent way to contain our current pandemic is to enforce a universal mask wearing and hygiene protocol.
People may be most infectious when symptoms are mildest or not present. There are many other viruses such as hepatitis and HIV, where a percentage of those infected show no signs of the virus. That asymptomatic carriers may unknowingly spread the infection, makes the virus both difficult to contain and to track. The fact that COVID-19 can spread so quickly by breathing and impacts so many aspects of our daily lives has made it more difficult to control.
Allison is a 43-year-old working mother of two children and lives in Hackensack, New Jersey, is of the group who believed she was an asymptomatic carrier and acted in the interest of her family and others. When her husband, Tim, fell ill in late March 2020, he was tested positive for COVID-19. Though she felt fine, Allison asked to be tested as well. In the early days of the pandemic, public knowledge and information changed daily, and resources for COVID-19 tests were limited, so health officials did not want to use the limited number of tests on those who did not show symptoms of fever, chest pain, or problems breathing.
Before Tim’s diagnosis, the family was very cautious about exposing themselves to the virus. They wore gloves, wiped down surfaces, and rarely went out. Though Allison didn’t have any symptoms, she continued with her regimen while Tim was recovering. Tim stayed in his bedroom while Allison put food outside the bedroom door for him to retrieve. She voluntarily self-isolated with her family for fourteen days and did not leave the apartment, ordering food by delivery instead.
Unlike Allison, when Mary Mallon was first discovered to be the person infecting those she served as a cook, she refused to be tested, but at the pressure of the police and the New York Department of Health, she was forced to give stool samples and then forced to quarantine on North Brother Island for two years. In 1910, after two years of confinement, a new health commissioner released Mary but made her promise not to work as a cook.
What was clear was that Mary had been advised she remained contagious, but what is not clear is whether she cared if she was a danger or if she just did not believe she had the disease because she had no symptoms. Judith Waltzer Leavitt, author of Typhoid Mary: Captive to the Public’s Health said Mary had denied ever being sick.
Mary’s story was so well known, even during her lifetime, she changed her last name so she could continue to work in food preparation. For reasons that have been speculated in novels and articles, Mary started working as a cook again. After that, she infected at least twenty-five more people, two of whom died. Authorities returned Mary to North Brother Island, where she was forcibly subjected to many tests for science, until she died in 1938. The ethics of how she was treated has been discussed and taught in public health and medical educational institutions for decades. At the time of her death, New York health officials identified at least four hundred other healthy carriers of Salmonella typhi, but no one else was forcibly confined or tested.
Different studies estimate the percentage of asymptomatic carriers of COVID-19 range from 18–50%. Authors of the studies and those who dispute how the conclusions in those studies are made have caused the wide discrepancy. Whether asymptomatic carriers of COVID-19 cause widespread infections is another point of contention.
And in those differences between interpretations of statistics and the widely varied physical effects of the virus lies the personal and ethical decisions of individuals who are infected yet don’t suffer from its symptoms.
In April 2020, Allison went to her doctor’s office for a routine physical. Her bloodwork showed she had the antibodies of COVID-19, meaning she had been recently infected with the virus. According to the Center For Disease Control, it can take one to three weeks after the infection for the body to make antibodies. Those who have evidence of a prior infection have some degree of protection against being re-infected with the virus. However, it is uncertain as to how long the protection may last. Those who have recovered from the infection can still shed viral material for up to three months, though the risk of passing the virus on to others is low.
A person with a result of positive antibodies could adjust their behavior as well. A National Cancer Institute says, “[S]ome people, upon learning they had a positive antibody test, might have behaved differently from people who were antibody-negative. If antibody-positive people believed they were protected during the period of study, they could have engaged in behaviors that could increase their likelihood of exposure to the virus, such as poor social distancing or failure to wear a mask in public places. If this occurred, the degree of protection inferred from this study might be an underestimate of the actual protection.”
In hindsight, Mary could have done other things to control the spread of Typhoid, such as washing her hands before preparing food. However, in the early 1900s, hygiene had not yet been connected with the spread of disease. If the health department told her she was infectious, what else did she need to convince her to do better? As a person who has to work, I understand Mary’s desire to continue working in the field in which she was most successful. But it ultimately comes down to a personal and ethical choice, one people make every day for various reasons.
Almost a century later, it seems we haven’t yet learned how to consistently handle these conflicts between personal well-being and that of the community. In the year before Mary was forced to quarantine, investigators believed Mary’s exposure ultimately infected at least three thousand New Yorkers of Typhoid, killing at least five people. Immunization against Salmonella typhi was not developed until 1911, and antibiotic treatment was not available until 1948.
When asked if she would get the vaccine, Allison said, “Antibodies last you so long. I will definitely get it.” Also, she wonders if she became infected again, would she be as lucky with another asymptomatic reaction. Seeing how much Tim suffered during his illness, she doesn’t want to be the cause of anyone else becoming infected, so she continues to limit her exposure to others.
