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Season 13 | Episode 3

Patient Zero - Updated

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Mexico City train passengers wearing surgical masks (Eneas De Troya/flickr/CC-BY-2.0)

The greatest mysteries have a shadowy figure at the center—someone who sets things in motion and holds the key to how the story unfolds—Patient Zero. This hour, Radiolab hunts for Patient Zeroes of all kinds and considers the course of an ongoing outbreak.

We start with the story of perhaps the most iconic Patient Zero of all time: Typhoid Mary. Then, we dive into a molecular detective story to pinpoint the beginning of the AIDS epidemic, and we re-imagine the moment the virus that caused the global pandemic sprang to life. After that, we update the show with a quick look at the very current Ebola outbreak in west Africa. In the end, we're left wondering if you can trace the spread of an idea the way you can trace the spread of a disease and find ourselves faced with competing claims about the origin of the high five.


Kathy Gregory, Beatrice Hahn, M.D., Greg Harrell-Edge, Jonnie Hughes, Judith Walzer Leavitt, Jon Mooallem, David Quammen, David Rosner, Nolan Smith, Nathan Wolfe and Carl Zimmer

Patient Zero Extra: Ebola

Robert Krulwich and our Senior Editor Soren Wheeler call up David Quammen to get a scientific perspective on the current Ebola outbreak.

Comments [6]

Comments [34]

Shannon from Orlando

Now that Gaëtan Dugas has been officially exonerated as Patient Zero in the American HIV/AIDS epidemic...any plans to do an update x2?

Oct. 27 2016 09:25 AM
yaeko from california

Valuable comments . I was fascinated by the information . Does someone know where I could get a fillable Mosaic 1 Grammar Answer Key copy to type on ?

Oct. 18 2016 11:52 PM

An update on the story about the origin of HIV in the US,

Mar. 04 2016 10:01 AM

The theme of this story is similar to Stigler's Law of Eponymy ('s_law_of_eponymy), that no scientific law is actually named after its original discoverer.'s_law lists several examples.

Nov. 28 2015 06:22 PM
Leah from South Africa

Another great podcast, Sawbones, did an episode on Typhoid Mary. Was really interesting, too! If anyone is interested, find it here:

Jul. 24 2015 07:51 AM
Toni L. Gatsby from NY

All diseases begin somewhere. Everyone of our bodies have dormant diseases inside of them, which when active can harm many and even kill. When sharing about the diseases and giving them a face, they are truly interesting, but frightening. The term "patient zero" is very common and it is associated with many epidemics we face. One case that many are familiar with is Mary Mallon. While she was cooking for families, she was the first to be infected with Typhoid, which was a common epidemic like Ebola or Swim Flu are today. By all the technological advancements we have created, scientists and doctors are working to find exactly where these dormant diseases are, and how we can stop them from becoming active.

Apr. 13 2015 09:13 PM
Mia Belanger from oviedo, FL

This was an interesting NPR. I didn't realize the finding of AIDS and HIV happened this way. The beginning of this story is unexpected, beginning with a female chef. This disease started in Africa and came to the U.S. in the 1960s. The disease switched from animals to humans in the early 1900s. Scientist were able to trace back this disease to chimpanzees in Western/Central Africa. The HIV in these monkeys is the most similar to the one contagious to humans.

Apr. 06 2015 02:43 PM
Zak Hassouneh from Earth

This NPR was very interesting to listen to. The term "patient zero" is very common and it is associated with every epidemic we face. We wonder where this new, harmful disease came from and who was the person spreading it to everyone else. It is often very hard to find the origin of diseases. A typical case most have heard about is Mary Mallon. She was cooking for familes and was the first to be infected with Typhoid. Now a common epidemic is Ebola or Swim Flu. We look for these causing agents so we can try to pinpoint where the disease, virus, bacteria came from and try to stop it from spreading. By finding where it comes from we then can see what might be able to fight against it and make antibiotics.

Feb. 02 2015 10:38 PM
Alice H. Nash

Science never fails to amaze me! I thought this was a great podcast. Epidemiology is one of the most interesting and important topics in the world right now. We have to learn from the past to protect the people of the future!

Jan. 26 2015 09:35 PM
Anna Chaucer

This podcast was great! Viruses and how they cause epidemics really fascinates me, and this podcast allowed me to learn so much about it. I also definitely think of the story of Typhoid Mary differently now.

Jan. 26 2015 03:36 PM
Alice Z. Lovecraft from FLORIDA

It's crazy to think that all these diseases started somewhere. That in someone's body there was a mutation of some normal germ that turned into something terrifying. Once you put a face on it, it gives it a different feeling. These stories were so fascinating and scary. When I was five my mom used to tell me a revised story of typhoid Marry to ensure that I would wash my hands. In middle school I saw a documentary on what life was like for her at the facility they kept her at and on the patients. It was creepy. Knowing that this happened not too long ago scares the poop out of me. It is nice to know that we have made so many advancements to take care of stuff like this.

Jan. 25 2015 05:54 PM
Elie S. Totsky from Orlando, FL

I think this was very interesting as this has used modern historical documents. I think this helps to make sure an incident as such will never happen again.

Jan. 19 2015 10:26 PM
Melanie from Canada

Patient Zero (the original) was the first podcast I had heard from you guys. I think it was on Upworthy around this time last year. It was such a well done piece that I have since listened to all your podcasts available on Stitcher. You guys are incredible. The way you tell a story blows my mind. Please, don't ever stop.


Jan. 18 2015 09:41 PM
Rudyard L. Kevoac from Florida

"future incidents in the future"

Jan. 16 2015 03:14 PM
Rudyard L. Kevoac from Florida

Patient Zero was a pretty interesting interesting report. It seems that modern historical texts slide over the Typhoid Mary incident, which is unfortunate, since it so clearly represented the development of the era. Additional analysis of the event can hopefully give modern historians greater insight into scientific/demographic intersections, and prevent future incidents in the future.

Jan. 16 2015 03:14 PM
Rudyard L. Kevoac from Florida

Patient Zero was a pretty interesting interesting report. It seems that modern historical texts slide over the Typhoid Mary incident, which is unfortunate, since it so clearly represented the development of the era. Additional analysis of the event can hopefully give modern historians greater insight into scientific/demographic intersections, and prevent future incidents in the future.

Jan. 16 2015 03:13 PM
Alex Sims from earth

This podcast was very interesting. We have all heard about "patient zero." In any infectious disease scientists have to look for the origin or starting point of where the disease is coming from. The first type of diasease they discuss is the Mary Mallon case. She was the origin for Typhon and had no symptoms but she was infecting people she was cooking for. This is a very common case people have heard about because it was one of the first documented patient zeros cases. I find this all very interesting because I myself have learned a lot about diseases and viruses. A lot of these diseases derive from animals whether it be from pig feises or bush meat. They get in contact with humans and start spreading rapidly. Scientists don't have medicene for these strange diseases because they have never had to come in contact but they can be very deadly. That is way the patient zero is so vital, so that they can track where these things orignate from and how to possiibly stop or cure the disease.

Jan. 12 2015 07:17 PM
Anna Morrison from Florida, USA

This podcast was very interesting because although most of us have been familiar with the story of Typhoid Mary, however, the real story is actually much different than what we study in elementary school. It's very interesting because Mary Mallon was the first healthy carrier of an infectious disease, and it is quite fascinating watching this type of patient being discovered over the years with different diseases, such as HIV (carriers can be asymptomatic for years while transmitting it to many different sexual partners), mononucleosis (or mono, which can be transmitted unknowingly after the patient has been ill), and most recently, ebola, which can be transmitted shortly before (and after, if the patient survives) they are symptomatic. Exiling these patients is probably, honestly, the best and safest method of exterminating it, but unfortunately, it can definitely be considered as unconstitutional or against human rights. Hopefully these other diseases can be eradicated like typhoid was without taking drastic measures.

Jan. 12 2015 06:33 PM
Baran from Maastricht, Netherlands

Can somebody tell me the name of the song that plays in the end?

Jan. 10 2015 12:32 PM
Will Wyatt from Flower Mound, TX

What were all the books listed at the end of the podcast? I thought there'd be links to them here on the website.

Dec. 26 2014 07:19 PM
Jim from Bellevue, WA

I think there was an obvious mistake in reporting the patient zero story. It was so obvious that it wasn't even mentioned. The strains of this all came from the male side of both chimps and men, and could only mutate through the male species. Where's the story about the woman with HIV?

Dec. 16 2014 05:13 AM
Joel from SF, CA

Gimme Some Skin, My Friend:

Dec. 12 2014 04:51 PM
Amirhossein from Tehran, IR

I really liked that part on mutation of HIV virus and how it passed through so much to actually kill a guy and…
Which arose this question for me that if the occurrence of such thing is so improbable, so what is this? ... Is it god’s way to punish all the homosexuals for being that way or it’s a gift from him that hey… watch over such diseases which led to sth like monitoring over “viral chatter”. Or it’s just the nature’s way to cleanse itself form the worst thing that ever happened to it, or it’s just another happening in a blue moon

Nov. 24 2014 11:29 AM
David from Oakland, CA

Apropos of your Ebola discussion, and how it'll find ways to last longer than a few days, new discoveries suggest it lives much longer in semen -- so it's now designing itself not to just kill, but to live and spread.

Nov. 19 2014 01:18 AM
Merlin from The Netherlands

First time listening to the podcast,
and loving it straight away !!!

Greetings from the Netherlands...

Nov. 18 2014 05:39 PM
John from Columbus, OH

Is that John Zorn playing during one of the high five segments?

Nov. 17 2014 11:20 AM
Kristjana from Iceland

Hello radiolab
Thank you for a fantastic show. Please stop sending me re-runs instead of new podcast. I would rather have none then the re-runs.
Best regards

Nov. 17 2014 07:05 AM

I have for some time found Mary Mallon the victim, her tale and not reality. Mary was knowingly poisoning her patron's from start in Ireland. Poison/flee then poison/flee was her pattern. While Mary clearly did not care that the next century would be spent on fruitless looks at asymptomatic carriers, Mary did know she was poisoning her patrons. As to when Mary learned her own feces gave her destructive powers and as to what that psychiatric pathology was is unimportant. A person's love of cooking for others' pleasure is in stark contrast to the harm she knew she caused. Mary's letters and cries for sympathies and her claims of victimization were probably the cries of the the guilty who derive perverse pleasure from injuring and killing others. Both of which she knew she was doing. Of course these claims of vicitimization are worth expressing but the backstory makes more sense, as societally disquieting as it may be. Even upon years of isolation and claims of victimization, Mary went on to do this time and time again under another name - ultimately caught doing so in a hospital. Mary was most likely and even more simply - poisoning her patrons with her feces.

Nov. 16 2014 10:22 AM
Nick from Normal

The update is in the 44th minute.

Nov. 16 2014 02:09 AM
Buddy Koerner from Vermont

First, I agree with Spillover - minute mark would be good for new content. Or an update with only the new stuff.

either way thanks for the update!


wow mollie. I dont think there is anything worse then a mega grammar nazi such as yourself. except real nazis maybe. boo-erns.

Nov. 14 2014 09:25 PM

Wow. Great episode. I have never heard someone go all the way back to "chimp zero." I don't think Gaetan Dugas is off the hook given that he was such a catalyst but clearly not patient zero.

Nov. 14 2014 07:33 PM
wilmot from Spillover

thanks for update. very interesting. not to be too "bad grammar alert" about it all, but it would be nice for regular podcast listeners to give us a minute mark to facilitate quickly finding the new material. thanks again for the show.

Nov. 14 2014 03:25 PM
Meir from america

Excellent reporting. As for Mollie's comment...Really??? Sit back and enjoy Radiolab.

Nov. 14 2014 01:24 PM
Mollie from Waldorf, MD

Oh No!!! Bad grammar alert!!!!! I'm intrigued, listening along...when I think I heard....went back to confirm it..."Her and her colleagues...." at 28:35 minutes. Really?? My ears cringed, I had to stop to recuperate...
Sorry, but no amount of amazing reporting, which this is, can make up for poor grammar for my ears!

Nov. 14 2014 12:31 PM

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