Germ Theory & Typhoid Mary

Becca: Welcome everyone! You’re listening to Unsavory. I'm Becca.

Sarah: And I'm Sarah.

S: When this episode comes out it will be Canadian Thanksgiving. So a Happy Thanksgiving to all of our Canadian listeners. Sarah, do you have any Thanksgiving plans?

Becca: boy, do we have an episode for you today. First, Sarah is going to share a bit about Germ Theory and then I am going to tell you about one of its most notable defiants: miss Mary Mallon AKA Typhoid Mary. You know those stories that just stick with you? This is one of those for me. I feel like it really has it all - historical references, disease, food, and one very devious woman. Anyways, we will get into it shortly.

At the intersection of true crime and food, it’s natural that food poisoning would come up pretty often, and so Becca and I have talked a lot about food poisoning on Unsavory before. We’ve talked about our own experiences with food poisoning and also we covered the Peanut Corporation of America peanut butter Salmonella outbreak that killed 9 people and there are many other mass food poisonings that we could and probably will cover one day. Even yesterday, I shared on our instagram that there are over 400 people currently sick with a salmonella outbreak of unknown origin in the US right now. And with all that food poisoning talk, I think most of our listeners probably already know that food poisoning is caused by some sort of contamination, most often biological contamination originating from humans, rodents, or microorganisms, and it is caused by bacteria, viruses or parasites typically transferred through saliva, blood, or feces and inadequate hygiene practices.

Food poisoning is still really common - it has actually decreased due to safety measures from COVID-19 - but still really common. The World Health Organization estimates that 1 in 10 people get sick and about half a million will lose their lives to food poisoning each year. So clearly food poisoning is still a huge public health concern, but it’s pretty incredible to think of how far food safety practices have come since the late 1800s. Only 150 years ago, people thought of wine and beer as "hygienic" beverages that protected them from water-borne diseases. 

So I’m going to tell you a little bit about the evolution of food safety. 

Up until the mid 1800’s, people didn’t know what germs were. They didn’t know about viruses and bacteria. They didn’t know why maggots showed up on dead bodies, and they didn’t know why food would spoil, or why wine would turn into vinegar. It’s interesting to think about because we know all about germs and how they are spread, but people really had no idea. 

Throughout history, people have blamed all sorts of things for causing disease - demons, ghosts, evil spirits, sins, spiritual blockages, and bad smells. There was even the theory of spontaneous generation, which claimed that some life forms, like rats, maggots, and flies, could arise spontaneously under certain circumstances. However, one of the biggest theories from the time of ancient Greece up until the mid-19th century, was called the Miasma theory. This theory proposed that all illnesses - from the common cold to cholera and malaria - came from clouds of dirty air called Miasma. This theory was first proposed by Hippocrates around 400BC and he wrote that "poisonous vapors" or "bad air" was the root cause of disease, and it makes logical sense, especially since many diseases are airborne, and a common symptom of being sick is coughing. So there is some logic there and the Miasma theory was supported by medical scientists up until the 19th century, but it wasn’t understood that there were microorganisms actually being transported through the air. Malaria actually gets it’s name from this theory - in Italian, mal means “bad” and aria means “air” - which represents miasma. Of course, now we know that Malaria is caused by a parasite that infects mosquitos, and has nothing to do with bad air. 

In the mid 1800s in England, there was a severe cholera outbreak that was ravaging the densely-populated working class neighbourhoods of London and this is the outbreak that really started to transition the prevailing paradigm from Miasma theory to germ theory. So, at the start of the cholera outbreak, people were actually taking many precautions to avoid bad air, avoiding the areas with an outbreak to prevent getting cholera. A bit about cholera - it’s a waterborne disease that causes diarrhea, and there was a cholera pandemic that ravaged the world from 1846-1860, and killed millions across the globe - Europe, the Americas, Asia, it was particularly bad in India and Russia - it was everywhere. The year 1853-1854 was particularly tough on London, England and over 23,000 people died, and there was a hotspot on Broad Street. One medical scientist, John Snow (did you watch GOT?), came forward with his theory that cholera was not spread by bad air but through water and food, and he proposed that there was a germ involved. John Snow went on to conduct a study and he actually identified the source of the outbreak as a popular public water pump in the Broad Street neighbourhood. Then he mapped all the cholera outbreaks in the area, and illustrated a connection between water quality at water pumps and cholera outbreaks, and his work would eventually be seen as a major event in the history of public health. 

And I say eventually because this groundbreaking work was largely brushed to the side. A leading epidemiologist at the time, William Farr, rejected John Snow’s hypothesis and in his annual report he stated that cholera was caused by Miasma as evidenced by an inverse relationship between cholera mortality and elevation above sea level. So, as you increased your elevation above sea level, by living on a hill or a mountain perhaps, your risk of dying from cholera went down. Now, I would say that’s probably because you’re less likely to be living in a poor, densely populated area of the city with access to cleaner water, and perhaps Mr. Farr had maybe not heard that correlation does not equal causation, but that was what he wrote and it confirmed the public’s belief that bad air was causing cholera. 

So John Snow’s work was kind of brushed off because the leading theory in medical science at the time was Miasma theory. I want to make a quick detour here to explain what theory means in science, because in casual conversation “theory” would be used to describe a hunch or a guess that’s not really based off of evidence but maybe just a casual observation or a feeling. In science, theory refers to a well-substantiated explanation of an aspect of the natural world that can incorporate laws, hypotheses and facts. And so when I say that Miasma theory was the leading theory, it wasn’t just a hunch, it was the scientifically accepted best explanation at the time. There were other theories, but this was the best one at the time. 

I wanted to make that distinction because I think it sets the stage for your story where you see how resistant people can be to a new theory. Like just imagine - we know and accept germ theory, cell theory, the theory of evolution because these theories explain things we know to be facts, and they allow scientists to predict what will happen in certain conditions. 

So just to be clear - a theory in science is quite evidence-based, not like a conspiracy theory for example, which is based on a hunch and not in evidence. But scientific theories can evolve. 

So - cholera outbreak, John Snow is a total hero but no one is listening and around this same time, some scientists are starting to pay attention to a new theory - germ theory. There isn’t a lot of evidence to support it yet though. Now, bringing it back to food, around the exact same time as the Cholera pandemic - a 33-year old French scientist named Louis Pasteur was being recruited to help France solve a problem they were having with alcohol. 

Louis pasteur was born in 1822 in France, and by the time he was 33 he was already a decorated scientist. He had done a bunch of work in crystallography and concluded that the asymmetry of molecules was a defining characteristic of life, and he had even started working on medical developments, such as creating a more stable form of quinine to treat fevers. He was approached by a local manufacturer of beet root alcohol and recruited to help figure out why this alcohol was going sour. Pasteur began looking at yeast under the microscope, and he realized that yeast was actually a living organism that was responsible for the fermentation process. He then began looking at spoiled alcohol that had gone sour, and realized that there was another rod-shaped organism in there - Mycoderma aceti - which is known as the “mother of vinegar”. 

The president of France at the time, Emperor Napolean III, recruited Pasteur to continue studying these “diseases of wine”, and that is where Pasteur discovered that microbes were causing the spoilage and heating the wine would kill the microbes that caused it spoil. He continued to experiment and found the exact time and temperature required to kill the harmful bacteria without changing the taste of the wine. 

How much wine do you think he drank during those experiments? 

It’s through those wine experiments that Louis Pasteur invented pasteurization, a process that is still used today and has saved countless lives from food and water borne illness. Tuberculosis actually used to be commonly carried in milk, but the pasteurization process kills the tuberculosis pathogen, and there is little to no risk of getting tuberculosis from pasteurized milk now - it’s no longer even listed on the CDCs list of food borne illnesses. But through the 1800s, it was known as the white plague so this process of pasteurization was incredible! It could make milk safe without impacting the nutrition. 

The first commercial milk pasteurizers were produced in 1882 and the first law requiring the pasteurization of milk was in Chicago in 1908. Although there was a lot of resistance and I think we could talk about that in another episode - I was going to get into the great raw milk debate in this episode, but I think that’s a great intro for another scandalous episode so I’m not going to comment on it here other than to say I am a proud drinker of pasteurized milk. 

One thing I find so interesting is just that the public and political resistance to scientific breakthroughs - like we’re seeing now with the vaccine -  is nothing new - it’s been there forever. People don’t like change, they don’t like things they don’t understand, and I know you’re going to talk about that too. 

Louis Pasteur’s work was a pivotal moment for the development of the germ theory of disease - because now there was documented proof and quality experimentation to show that there were actual microorganisms causing spoilage - and Pasteur went on to apply his work to the world of medicine and he actually invented the vaccine for chicken cholera, anthrax, and rabies. After Louis’s work, another scientist named Robert Koch went on to expand on the germ theory of disease and by the end of the 1880’s, the miasma theory was basically busted. Public health and medical science was fully transitioning to a generation of better hygiene to help prevent the spread of disease. And with that, I’m going to toss it to you to tell me one of my favourite stories of all time. 

Becca:
That was amazing, Sarah. I've always found Germ Theory so interesting, and that was the perfect segue into my part about typhoid and Typhoid Mary. Do you remember that terrible song called “Dirty Mary”? It would have come out during our first undergrad degrees - like 2010ish. Well ever since I started this research I've had it stuck in my head. And I even went to look to see if the lyrics were about Typhoid Mary and I can confirm that they are not. But I have to say I'm excited to get this story out of me and hopefully get this song out of my head as well. 

But before we get started some of the key references that I used include an amazing book by Anthony Bourdain, a paper by Marineli called “Mary Mallon and the history of typhoid fever” and the podcast This Podcast Will Kill You and their episode titled ‘There's Something About Mary’. I listened to the first half of the episode where they describe the epidemiology of typhoid, and I would highly recommend giving it a listen if you want to learn more about the history and onset of the disease.

Ok, so what exactly is typhoid? Typhoid or typhoid fever is a disease caused by the Salmonella Typhi bacteria. It is often grouped under the category of Enteric Fevers with another disease called paratyphoid fever, which is similar to regular typoid, but is typically less intense and with a shorter duration. Typhoid symptoms include fever, weakness, stomach pain, headache, diarrhea or constipation, cough, loss of appetite, or a rash - so basically all of the worst symptoms. In more severe and untreated cases internal bleeding and death are possible. Without treatment the instance of death is really high with a mortality between 10-30%; but with treatment it is only 1%, which does still seem high to me. The infection can last anywhere from a few days to a few months.

Typhoid bacteria is most often spread through food or water, and the culprit is almost always POO. So with food, it might be spread through unsanitary food handling practices - like not washing your hands. And with water, contamination might occur if the water ways aren’t properly disinfected prior to drinking. Because of this, it is often countries, cities, or areas without proper sanitation infrastructure that are affected by typhoid. So developing countries and lower income areas often suffer. And if we have learned anything from the water crisis in Flint Michigan, or that of the rural Indigenous communities in Canada, clean drinking water is still inaccessible to many in North America - and of course, across the globe. Even in a country where clean water is defined as a right in our charter, politics and racial segregation continue to play a huge role in the access and availability of this resource that we all need to live. 

But with that being said, typhoid specifically is more often found in parts of Asia, Africa, the Caribbean, Central and South America, as well as the Middle East. The WHO estimates that there are about 21 million cases of typhoid each year, and 222,000 associated deaths. And the majority of cases occur predominantly in South Asia. So in Canada there are only about 150 confirmed cases of typhoid each year, and in the US that number is around 400 a year, but the actual number is likely much higher (Government of Canada, n.d.). Most of these cases are reported by people who recently travelled to areas of the world where typhoid is more rampant (Centers for Disease Control and Prevention, 2020).

The reason this disease is so nutritionally relevant is that it really impacts the digestive system. After we consume the contaminated food or drink, the Salmonella typhi bacteria begin to invade these little lymph node-type follicles in the ileum, or the last part of the small intestine, called Peyer’s Patches. Since these patches are a part of the lymphatic system, they play a really important role in immune surveillance in our digestive tracts.

With most pathogens, the Peyer’s Patches will act as a first line of defence. They are full of white blood cells, which are key players in the body’s immune system. White blood cells trigger inflammation to help fight off infection and protect the area. There are two known disorders associated with Peyer’s Patch dysfunction - both Crohn’s disease and graft-versus-host disease, which is a condition that sometimes occurs after a stem cell transplant where the donor's stem cells attack the host's body. Both of these disorders result in digestive distress.

Anyways, the Salmonella typhi bacteria can live within our cells, and one of the first things they do is enter the white blood cells. Here they start to replicate and travel with the cells wherever they go (Jung, Hugot, & Barreau, 2010; This Podcast Will Kill You, 2020). And this is how it moves out of our digestive tract. So the bacteria attacks the sensor system designed to protect you, which is really scary.

So you know how I said that typhoid isn’t very common in North America. Well this hasn’t always been the case. Prior to Germ Theory and knowledge around public hygiene and sanitation, Typhoid really had its way with people. Between 1607 and 1624 it was responsible for the deaths of other 6,000 English settlers in Jamestown, Virginia. And during wartorn times, Typhoid fever really thrived, often killing more soldiers than combat itself. During the American Civil War in the late 1800’s, the unsanitary living conditions led to typhoid, which took the lives of over 80,000 soldiers. WAY before this, in 430 BC, it is said that the plague of Athens was actually the result of Typhoid Fever (Smith, 2021). So this disease has a history.

In 1872 a doctor named William Bud was able to demonstrate that typhoid was transmitted through human feces in drinking water. Despite the fact that many scientists contributed to the isolation of the bacterium, the genus “Salmonella” was named after an American pathologist and USDA research administrator: Daniel Elmer Salmon. After the discovery of the microorganism more knowledge was accumulated on Typhoid and a vaccine was developed. In 1896 it was approved for military use, which led to a huge improvement in the health of soldiers at war, and it was soon no longer a military problem.

During WWI, the majority of soldiers were inoculated and more soldiers were killed by combat than the disease. To put things in perspective, before the vaccination, typhoid would infect about 14,000 soldiers out of every 100,000. Following the rollout of the vaccine and during WWI, typhoid only killed 37 soldiers out of every 100,000 (Alder, 2016). So you could say that vaccines work.

At this point you may be wondering how this relates to a lady by the name of Typhoid Mary. And I’m going to tell you...right now. Mary Mallon was born in 1869 in Cookstown, Northern Ireland. She was tall, blond, with blue eyes and a rigid jawline. She emigrated to the US in 1883 to start a new life and she began picking up jobs cooking for wealthy families. The cook in a household was seen as the top of the hierarchy when it came to domestic service jobs. And Mary really thrived in that role. She was referred to as a “pretty good cook”, but tended to be “difficult to talk to”. Her signature dish was a homemade peach ice cream, which is an important detail to remember.

From 1900 to 1906 Mary cooked for at least six families. And in 1906 she began working for Charles Henry Warren, who was a wealthy banker in New York City at the time. During the summers the Warren family would summer in Oyster Bay, Long Island. From August 27th to September 3rd that year 5 of 11 people living in the Warren home started to feel ill and presented with typhoid fever. This included Warren’s two daughters, two maids, and the gardener.

The family was too ashamed to report their illness initially, since typhoid was generally a disease that thrived in unsanitary or overcrowded living conditions. And the Warren’s were extremely wealthy, with five large homes. Charles, the dad, was especially worried that if people caught wind of their family’s illness, that no one would want to rent the home during the next season. So he decided to hire a team of experts to prove that the disease had come from outside of the home.

Local health authorities assessed the drinking water and all milk products, since unpasteurized dairy was also a known source of typhoid contamination. But the results from this investigation were inconclusive. Warren then reached out to Dr. George Soper, a mutual friend and sanitary engineer. Dr. Soper was well known as a “doctor to sick cities” and even though this was a bit of an unusual request, he immediately agreed to the job. After reviewing the health authorities findings, he began to interview all the members of the home, as well as any visitors that had visited over the past 10 years. But he couldn’t link the typhoid to anyone that had interacted with the family. His findings also suggested that the bacteria had not come from contaminated water or milk in the home.

One thing that Dr. Soper uncovered was that earlier in August of that year, the Warren’s had hired a new cook. What was even more suspicious was that she had since gone missing. She left three weeks following the family’s initial typhoid diagnosis, with no formal resignation or indication of where she was going. This was the circumstantial evidence that Dr. Soper needed; and it was really his only evidence. So at that point he focused all of his efforts on finding Ms. Mary Mallon.

Soper went to the employment agency that she used and was able to get his hands on her employment history from the past 10 years. He reached out to many of her previous employers and you’ll never guess what he found…. In 100% of the homes that she had worked in, there had been a typhoid outbreak.

I am going to read you a quote from Soper’s investigation:

“Following her trail backward to cases in 1904, I found she had worked at the home of Henry Gilsey at Sands Point, Long Island, where four of seven servants suddenly got the disease. Going back still further, I found that five weeks after Mary had gone to cook at the summer home of J. Coleman Drayton at Dark Harbor, Maine, in 1902, seven out of nine persons in the house contracted typhoid, and so did a trained nurse and a woman who came to the house to work by the day. There had been an outbreak of the disease in New York in 1901, and I had reason to believe that Mary was behind this. In 1904, Tuxedo Park, the fashionable summer resort, was stricken ... and (I) discovered she had cooked there in that time.”

But there was still a 2-year gap in Mary’s employment timeline. Dr. Soper had been on this case for over 4 months at this point but he was becoming a bit obsessed. Where had she been those 2 years? And where was she hiding now? This whole thing became very “Catch Me If You Can”. 

What was then more commonly known as “Filth Theory” - which was the concept that disease came from filth; it had recently been replaced by “Germ Theory”, which as you mentioned is the idea that disease is the result of microorganisms or pathogens. Dr. Soper laid out the evidence he had - the Warren’s home was maintained and clean, there were no indications of contamination elsewhere, and even Mary Mallon was reported to have seemed healthy leading up to the typhoid outbreak. He started to wonder if it was possible that Mary had typhoid without being symptomatic. And that’s when he made a scientific discovery - the very first asymptomatic carrier of disease in the United States. Being an asymptomatic carrier essentially means you are infected with a pathogen, but don’t display any symptoms of the associated disease.

There was one other case of a typhoid carrier in Germany, and Dr. Soper started to focus his research there. Another doctor & bacteriologist - Dr. Robert Koch - had studied a baker who was spreading the bacteria to bakery patrons, despite having no symptoms herself. This woman had previously had typhoid, but had since fully recovered. Dr. Koch obtained and tested a fecal sample and found that it was crawling with typhoid bacteria. So by not properly washing her hands, she was spreading the infection to people eating her baked goods.

Dr. Soper’s American scientific breakthrough made him more desperate to find Mary. He knew this was going to make him famous. Since this was the early 20th century, the fatality rate for typhoid was over 10% and these findings had the potential to save lives. 

After many more months of interviewing witnesses and combing through reports, Dr. Soper received word that another wealthy family who lived on Park Avenue had an unexpected outbreak of typhoid fever. The daughter and the maid had fallen ill, and the daughter died soon after. The nurse who was caring for her then also began showing typhoid symptoms. One food item consistent from infected family to infected family was, unsurprisingly, peach ice cream. The raw peaches in the cool ice cream made for the perfect environment for Salmonella typhi to thrive. And if you mix in an asymptomatic carrier of the bacteria, you have a recipe for disaster.

Soper reached out to the family and found that a cook matching Mary Mallon’s description had recently been hired by the family. And it turned out that it was Mary working under an alias. About 3,000 people in New York had contracted typhoid that year, and Soper accused Mary as being the reason for the outbreak. He began stalking her, and tried to get samples of her urine, feces, and blood - which clearly upset Mary. He then reached out to the NY Department of Health and was given permission to bring her in for testing. She was apparently very uncooperative when they went to pick her up, which sounded more like an arrest. But as you probably suspected, her stool sample was positive for Salmonella typhi. 

Because there was no immunization until 1911, and no antibiotic treatment until 1948, authorities figured the only course of action to keep the public safe was to send Mary to quarantine on North Brother Island where there was an isolation hospital that was initially created to house Smallpox victims. It later expanded to basically imprison those with tuberculosis and typhoid as well. And a little side note - I found a source that says it’s now illegal to visit this island without a permit, which is apparently a bird sanctuary today.

In 1909, Mary tried to sue the New York Health Department for her unlawful confinement, but the suit was unsuccessful since the department claimed her confinement was protecting the general public. And this kinda lead to a divide in the community about whether or not she should be incarcerated since many believed it was a violation of her civil rights.

She was in the hospital for 2 years, where she was forced to give 163 stool samples; and 120 of them were positive for typhoid. They tried to remove her gallbladder, which is often where typhoid collonizes in asymptomatic carriers, and she rejected this surgery. Which makes me wonder if she was ever educated on what it meant to be a carrier. They also tried a bunch of treatments on her - like the use of laxatives and brewers yeast - but they were all unsuccessful.

In 1910, a new health commissioner was named and they promised to free Mary IF AND ONLY IF she would stop working as a cook. She agreed and was released back into the public. Except she had straight up lied and continued to work as a cook for unsuspecting employers under another name. This girl just loved her job.

Months later Mary Mallon, who was now going by “Mary Brown” was discovered again working as a cook at Sloane Maternity Hospital. So not only did she refuse to stop working, but she had plopped herself into a role working with a more vulnerable population. In a matter of a few weeks she had spread the infection to at least 25 people, two of whom died.

Mary was sent back to North Brother Island for violating the terms of her release. On Christmas in 1932 Mary had a stroke, leaving her paralyzed. Six years later, in 1938, she died of pneumonia at age 69. There is some conflicting information as to whether or not an autopsy was performed. But some sources say that one was done and she was shedding the bacteria through her gallstones, which made researchers wonder what would have happened had they removed her gallbladder. But others claim that no autopsy was done and that this is an urban legend...so it’s unclear whether that’s true. She was then at the St. Raymond’s Cemetery in the Bronx, where she remains today.

Dr. Soper published his findings on Mary in 1907, prior to her imprisonment, and later wrote a book in 1939 titled The Curious Case of Typhoid Mary. His investigation found that she was responsible for spreading typhoid to at least 122 people, resulting in five deaths (Bourdain, 2001; Marineli et al., 2013).

But was Mary a villain menacing the health and wellbeing of the public or was she a victim who had her civil liberties stripped away? While this story took place over 100 years ago, this conversation continues today with the onset and spread of COVID-19. And I think we really have to take a look at why Mary’s story is one that has been highlighted and criticized for over a century. Let’s start with the fact that she was an immigrant woman; she was a part of the “working class”, and was unmarried with no children. I think that her defiance against societal norms made her out to be more notorious than she actually was.

Nowhere in my research did I come across any information about efforts to educate Mary on her carrier status. And I can only imagine that she was terrified, and just trying to get by. Education is so important when it comes to disease transmission, public health, and safety. Misinformation or a lack of understanding can be deadly and typhoid Mary is the perfect example.