Outbreak | S1 E11 | Forensic Files | FULL EPISODE | Forensic Files

in 1985 121 people in South Dakota and Minnesota were struck with a mysterious illness there had been only one outbreak
like it and the last time it happened Medical detectives couldn't figure out the cause
[Music] [Music] Valley Springs South Dakota a tiny farming community of about 800 people
not far from the Minnesota border it's a community of farms and Suburban professionals many of whom work in the
nearby city of sou Falls people here are accustomed to hard work and the hard weather and aren't the
type to complain so when some residents began suffering from irregular heart rhythms fevers weight loss diarrhea
edginess and mysterious aches and pains they wondered if it was more than a coincidence I was just fidgety and
nervous and uh not all the time I guess that's what threw you off it had been that steady you couldn't have put up
with it heart would be you know you feel your pulse and it just pounding you could feel your heart pounding and you
achd your legs and arms hurt real bad and I started getting chills then I'd get hot flashes then I couldn't eat and
I'd be nauseated every everything was just happening really really fast at first doctors were confused about the
symptoms Jane nad's Doctor thought she was having a nervous breakdown and put her in the hospital I'd never you know
had any of this problem before with a mental problem so he put me on a mood elevator and about 8 hours later my
heart was 160 beats per minute and I just knew I was going to have a heart attack it felt like it was just flying
out of my yes 10 m down the road in lever Minnesota the stories were the same Tony dis Panet suffered heart
symptoms too and immediately went to the emergency room certain he was having a heart attack well about 3:00 in the
morning approximately three U I woke up with a a tightness in my chest like some it
did it felt like somebody was sitting on it test revealed it wasn't a heart attack but he spent three days in the
hospital as doctors tried to find out the cause some of the local Physicians thought it was the flu or a virus but
after weeks of suffering the residents started to compare notes there were folks that were sick and had been sick
for a long time and a couple were had gone close to death and they couldn't figure out what was wrong with them and
they didn't know if it was contagious if it was something in the water and they were all feeling these same symptoms and
then they were hearing of other people that were feeling these same symptoms when Richard Jacobson went to his doctor
he was told that his thyroid was malfunctioning and was sent to the area's leading thyroid specialist when
Jacobson called The Specialist he had just one question doc can you tell me why there's five people in my small town
with the same condition Dr Michael McMillan has been a thyroid specialist in South Dakota for the past 30 years at
first he thought Jacobson was exaggerating but just to make sure he decided to do a little of his own
investigating he went to the local hospital and looked through the x-rays and medical records of some recent
patients he discovered something alarming there had been an increase in the number of patients with thyroid type
complaints but there was a problem because in every x-ray the thyroids were perfectly normal the thyroid is a small
butterfly-shaped gland at the base of the neck which produces hormones that control both metabolism and growth an
overactive thyroid floods the body with hormones disrupting the entire nervous system causing symptoms such as heart
fluctuations weight loss diarrhea nervousness muscle aches and pains Dr McMillan searched the medical
journals for Clues trying to find out what could be causing an outbreak of thyroid problems in the area and I came
across a title that said first ever epidemic of Silent thyroiditis York Nebraska well York Nebraska is about 120
mil south of here the outbreak in York Nebraska happened just one year earlier residents complained of the same
symptoms heart problems fevers fatigue loss of appetite and weight loss so many people were ill it threatened the
economy of the small farming Community doctors from the Centers for Disease Control in Atlanta were called
in to investigate but just as they arrived the outbreak of Silent thyroiditis Ended as mysteriously as it
had begun the residents recovered and the cause of the York outbreak was never discovered Dr McMillan immediately
called the CDC to let them know it was happening again Dr Michael McAn I'm trying to get a hold of Dr Dan fishine I
was knew that it was going to happen again because I knew the one thing we all admitted is even the people who
thought it was a virus we didn't know what virus we didn't know what it was caused by so I knew that was going to
happen uh again and so I was uh not quite expecting but certainly was not surprised as the CDC prepared to
investigate this outbreak the number of cases was Rising even if it just spread to through Falls with all the people
here let alone Minneapolis or Detroit or something we would have a major medical
catastrophe on our hands investigators needed to find the cause of the outbreak before thousands
were affected in June of 1985 there were 50 cases of the mysterious thyroid outbreak con
concentrated in two nearby towns lever Minnesota and Valley Springs South Dakota the Cent for Disease Control in
Atlanta was called in to investigate certainly one of the most puzzling things about the outbreak is we didn't
know what it was due to um and this made it incredibly difficult uh was it in the
air was it in the water was it in the food there there was just no way to know investigators needed to know as much
about the outbreak as possible it was striking both men and women equally all age groups were affected there appeared
to be no occupational Association and no work site or School clusters entire families were affected was it possible
that the outbreak was being spread person to person everyone suspected of having the
disease was given a blood test and interviewed about where or how they might have contracted it you talk to
patients and you hope that by doing unstructured interviews you'll get some ideas one of the questions that I
thought was kind of cute that the epidemiologist asked everybody was what do you think causes
this and the most frequent response there had been a lot of tornadoes in this area the year before
the most frequent response was I guess those tornadoes stirred up some chemicals and that got got into our
water supply but in order to determine what was causing the outbreak investigators
first had to figure out what the problem was blood tests revealed that all of the
victims had an excess of thyroid hormone in their system in some cases the levels
were 8 and 10 times above normal tests of the drinking water did not reveal anything which could have caused the
outbreak Dr Lewis Braverman is the country's leading expert in thyroid disease diseases he was asked to examine
some of the sick patients in South Dakota we then went out to a small community called Beaver Creek if I
recall and went into one household where there were four generations in the house who had all of
the signs and symptoms of thyrotoxicosis and none of them from a four-year-old child to an 85 or 90y old
great grandfather had an enlarged thyroid since the thyroid glands of these victims weren't enlarged they had
no idea what was causing these symptoms in the past enlarged thyroid glands were so common in this part of
the country it was known as the goer belt a goer is the term for an enlarged thyroid this part of the country is
called the goer belt because there was iodine deficiency here uh there's no iodine in the soil uh there's nobody
eating seafood and so people used to get large iodine deficient goers the condition was so common that in 1922 the
Mayo brothers opened the Mayo Clinic in nearby Rochester Minnesota offering safe
affordable surgery to alleviate the huge number of thyroid problems in the region
over the years as diets improved the thyroid problems went away but this outbreak was different all of the
patients had normal thyroids and for some patients the condition was serious one of the cases was a patient I had
seen in the Intensive Care Unit here in the hospital and it was an older lady who whose heart had suddenly started
beating irregularly and she'd gone into heart failure to find out if this was indeed a virus Health officials decided
to take throat and feal specimens for an analysis but all of the tests were negative then Dr McMillan noticed
something interesting the geographic location of many of the victims here was a community of Valley
Springs and then 3 miles across the highway was a community of garritson which was almost the same size there
were nine people in Valley Springs with the disease and nobody in garon with the
disease how could those two communities what what was what was the difference in
fact the epicenter of the outbreak was L Minnesota and there were no cases west of Valley Springs but that changed when
a resident of Sue Falls called Dr McMillan to say that she was suffering from the thyroid disease her name Ronda
pesy her parents owned a grocery store in Valley Springs where she occasionally purchased her groceries Dr McMillan
drove out to visit her parents Larry and Margaret long and to to take a look around their store the Longs did not
have thyrotoxicosis but their daughter did Dr McMillan wanted to know why when Dr McMillan learned that the
daughter of a grocery store owner developed thyroid toxicosis yet her parents did not he decided to
investigate the grocery store owned by Larry and Margaret long had a special y item extra lean ground beef Dr McMillan
asked the Longs how often they ate the ground beef themselves they laughed and said never it was such a popular item
they were always sold out it was a great meat it was uh it was running about 90%
lean but the long said their daughter might have taken some with her on her last
visit on a hunch McMillan took a sample for analysis by now there were more than 100 cases of
the mysterious thyroid outbreak and for some the symptoms were troubling when I had that thyroid scan a couple gals that
work in the hospital they thought I had cancer is what they told me they told me
this personally that we thought you were dying of cancer CU I'd look so bad when
I went for this thyroid scan then of course the world's greatest endocrinologists were called in and uh
and uh we had I remember the meeting with them and we laid out out all the data told everything and they sat there
and Shrugged their shoulders and said we don't know what this is the only thing they knew was that patients had eight or
10 times the normal amount of thyroid hormone in their bloodstream causing heart problems fatigue muscle aches and
pain investigators finally got a break when they heard of an entire family with thyrotoxicosis it was a large extended
family all of whom had confirmed cases of the thyroid condition all except one it must have been eight or 10 people we
bled everybody in the family did their blood test and everybody had elevated thyroid function tests except one person
and that was a teenager but how was the teenager different from the other family
members who got sick the father told investigators he worked at the local meat packing plant and regularly brought
ground beef home for his family it was the same plant which supplied the Long's grocery store with
their specialty hamburger the extra lean ground beef samples of the hamburger were collected for analysis and taken to
a local pathologist using a cryostat a portion of the hamburger was frozen in a matter of seconds we convert the tissue
really into a block of ice that makes the tissue firm enough that we can cut thin sections stain them look at them
under the microscope and make a diagnosis under a microscope the pathologist noticed something unusual something not
normally seen in ground beef bits of animal thyroid mixed into the ground meat animal thyroid contains extremely
high levels of thyroid hormones was it possible that this was causing the outbreak of
thyrotoxicosis in in the two small communities to find out doctors conducted an experiment one can say well just because
you find it in the hamburger how do you know that when the people eat the hamburger that they're really absorbing
the thyroid hormones so our next step was to feed the ground beef from Minnesota to rats one group of rats were
fed the raw hamburger collected in Minnesota and for comparison another group was fed raw Burger purchased near
the laboratory in Worster Massachusetts the rats which ate the Minnesota Burger exhibited all the signs of thyroid
problems these rats were wild rats I mean they were very jittery nervous and this is compared to the rather tranquil
normal behavior of the rats fed the Worcester hamburger so that there's no question that these rats were if one
could use the Expression clinically thyrotoxic but residents of Valley Springs and Lou weren't eating raw
hamburger and cooking the meat usually kills all bacteria and microorganisms most of us eat cooked
hamburger and as a matter of fact people in the midwest tend to cook their hamburgers much more so than we do in
the Northeast investigators next step to do some tests on humans they also wanted
to know how an entire family developed thyrotoxicosis while their young son did not when investigators from the CDC
found a large extended family who all suffered from thyroid problems except their young son they wanted to know
why interviews with the family revealed that the boy didn't eat meat except for an occasional pepperoni pizza I hate
meat I like this oh and he's my son this was an important Discovery the next step
to confirm that the tainted hamburger created elevated thyroid hormone levels in humans as it did with the rats even
after it was cooked so that we did uh obtain four young Physicians uh to participate in the study and what we did
was essentially bring them in in the morning fasting uh Drew their blood and fed them an extremely well-cooked half
pound hamburger uh which they enjoyed immensely since the was smothered in onions and on toast so that it was a
very tasty uh breakfast the meat used in the experiment was the same that was sold in the local stores it came from
this local slaughtering house in L Minnesota but how was the local meat being contaminated Public Health
officials inspected the local meat packing plant and learned something interesting the plant had been a kosher
killing plant up until a few years earlier when animals are killed kosher they're actually bled to death and the
thyroid gland it has a real intense blood supply and it's really red except that if you bled the animal to death
then it would look white and it would look completely different and when the thyroid gland changed color it was
easier for the but to see and remove the animal thyroid was then sold to drug companies all of the meat packing
companies would carefully dissect the thyroids out and sell them to the drug company so they could make thyroid
extract U to treat other people but two things happened first this Meat Plant discontinued its kosher killing
production and with the development of synthetic hormones drug companies no longer purchased the animal thyroids
from slaughter houses the result since the animal thyroid wasn't sold to the drug companies it was included along
with the rest of the nect trim from the animal's gullet and inadvertently passed
along for human consumption the gullet basically is this part of the cow's neck and the muscles that are trim that are
lowfat are these muscles here the the sternomastoid muscles on humans the thyroid gland sits right under those
muscles and if someone is not pain P attention as they're trimming it's very easy to clip off a bit of thyroid gland
as they take off the muscle when the animal's thyroid gland was mixed in with other ground meat for hamburger it
caused the highly elevated levels of thyroid hormones in those who ate it the Meat Plant was producing the
equivalent of 3600 hamburger patties each day but as soon as the problem was discovered they immediately Rec called
the beef and instituted safeguards to prevent the problem from recurring well it was almost like the Eureka type thing
we were we were really quite thrilled we thought that we had at that point in time discovered the cause of this
epidemic and uh was something relatively simple a simple solution to a complicated
problem after 7 months of Investigation the cause of the outbreak was finally discovered
and investigators believe that the tainted meat also was the cause of the outbreak in York Nebraska the year
before shortly after this outbreak the US Department of Agriculture instituted strict guidelines for the trimming of
meat from neck muscles and declared the thyroid gland was to be considered unfit
for human consumption but the residents of Valley Springs and L don't care much about their place in medical history and
they aren't the type to hold a grudge 121 residents develop thyrotoxicosis and all recovered
fortunately there were no fatalities it's become one of cdc's major teaching cases because it illustrates all sorts
of things that are really not usually encountered but are very important lessons for young
epidemiologists the outbreak was halted promptly thanks to skill in intuition and a little bit of
luck all are important ingredients in a successful medical investigation [Music]
a [Music]

In 1985, 121 people in South Dakota and Minnesota were struck by a mysterious illness.

Brief Summary

In 1985, a thyroid illness outbreak in South Dakota and Minnesota was traced to contaminated ground beef, affecting 121 residents.

Key points

Mysterious Illness Strikes. In 1985, 121 people in South Dakota and Minnesota fell ill with a mysterious condition.
Thyroid Outbreak Investigation. Doctors discover an alarming increase in thyroid complaints among residents.
Ground Beef Contamination. Investigators find animal thyroid mixed into ground beef, leading to elevated thyroid hormone levels.
CDC's Major Teaching Case. The outbreak serves as a crucial lesson for epidemiologists on the importance of thorough investigation.

Episode highlights

Episode quotes

I just knew I was going to have a heart attack.

A resident describes the panic of their symptoms.

2:27WatchMar 6, 2025

Tension

75/ 100High tension

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