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