6 Dangerous Diseases Hiding in U.S. Backyards

microbes are invisible so it's easy to forget that they're all around us all the time they're in everything we eat and drink and on every surface that we touch a lot of microbes don't hurt us but there are some that really can and even deadly pathogens are closer than you might expect lurking in tiny rodents or a tacky decorative fountain right here in the United States there are a surprising amount of diseases hiding in your own backyard here are six of them chances are you've heard of the Black Death a plague of such epic proportions that it killed a third of Europe's population but what you might not know is your city of pestis the bacterium that caused the plague is far from gone adorable furry animals and their fleas carry Y pestis bacteria basically everywhere west of Texas in the continental United States and this bacteria can infect humans and inject our cells with deadly toxins starting with our immune systems in bubonic plague the bacteria multiply in lymph nodes making them swollen and painful this comes with fever headache and weakness once the infection gets into the bloodstream it becomes septicemia plague and if it migrates to the lungs that's pneumonic plague now it's hard to know how many critters are carrying this ancient terror but scientists often use coyotes as a sentinel species like the classic canary in the coalmine Sentinel species help predict risks to humans serving as an early warning of potential danger coyotes are scavengers that eat lots of small mammals both living and dead which are common carriers of the plague so testing them is at least helpful even if the data is not perfect a massive study took blood samples from over 17,000 coyotes from 2005 to 2009 and found that about 10% tested positive for exposure to plague coyotes that had been infected were found in virtually every state west of the hundredth Meridian which runs through the middle of North Dakota and Texas that seems pretty widespread but luckily human cases of the plague are pretty rare according to the CDC there have been an average of seven per year in the u.s. and since 1970 all but one reported case occurred in the West because Y pestis is a dangerous neighbor infection control programs target susceptible species like prairie dogs to protect them scientists engineered an oral vaccine out of a harmless virus by tacking on Y pestis antigens pieces of the bacterium that immune cells use to recognize the disease and fight back researchers added the vaccine to treats flavored like sweet potatoes or peanut butter which were a huge hit with wild prairie dogs in test runs in Colorado and Utah so hopefully these cheap and efficient medicinal snacks will help protect more prairie dogs and nearby humans in the future small rodents can also carry another ominous disease called the Sin Nombre virus or SNV it was first discovered in 1993 after a cluster of mysterious deaths in relatively young healthy people in the Four Corners region where Arizona New Mexico Colorado and Utah meet the virus was originally called the four-corners virus but residents objected to it and it was renamed the Sin Nombre virus which funnily enough means the nameless virus although scientists had known about hantavirus –is in other countries for many years SN V was the first of several so-called new world hantavirus as we discovered the early symptoms of infection could be mistaken for the flu fever chills and muscle aches but as the disease progresses it affects the lungs so patients drown in their own fluids it's not entirely clear what causes this effect but researchers think that the virus may send the body's immune cells into overdrive in the lungs causing inflammation that damages the tissue hantavirus infection is relatively rare on average 30 people a year infected in the US but it's quite deadly killing 35 to 50 percent of its victims we don't have a vaccine yet so supportive care is all doctors can do cases of snv have been reported from coast to coast and it's mostly carried by the deer mouse a creature that even the CDC calls a deceptively cute deer mice live pretty much everywhere in North America although they seem to be especially virus Laden west of the Mississippi River for example a study of nearly 2,000 deer mice in California found that about 12 percent had antibodies against SNV indicating that they had been exposed to the disease but they don't have obvious symptoms of sickness and we can get snv just by breathing and dust contaminated with they're infected poop fortunately as far as we know snv doesn't seem to spread from person to person so just be a little wary of wild mice and you should be fine plague bacteria and the Sin Nombre virus are often found in remote locations like big national parks where small furry critters thrive but nearly half of Americans who got tularemia between 2001 and 2010 lived in urban counties and it's not confined to western states either cases have been reported everywhere except Hawaii tularemia is caused by a bacterium called frances ella – Lorenz's this disease is pretty rare with only 200 to 300 cases a year in the US but it's incredibly dangerous inhaling as few as 10 microbes is enough to cause a full-blown infection and depending on the way the bacteria gets into your body the symptoms are different the bacteria tricked their way into human cells then go wild multiply and kill them and they can attack any combination of skin lymph glands eyes throat or lungs so it's often misdiagnosed which is bad news tularemia only responds to a few antibiotics so misdiagnosis can lead to improper treatment and more risk of death mortality rates are between 2 to 24 percent F – Lorenz s bacteria can be transmitted by ticks and deer flies but Americans have also caught tularemia from pet cats and hamsters in an outbreak of tularemia in Martha's Vineyard in 2000 mowing the lawn was even linked to the disease probably because they were chopping up dead infected rodents with the grass even though there's a vaccine for tularemia it's only partially effective for now researchers are still working on it in the meantime you can avoid the disease with some common sense watch out for ticks and don't handle wild animals and maybe this is a good excuse to put off mowing your lawn hypochondriacs beware you don't even have to leave your apartment to get Legionnaires disease cases were reported in every state in 2016 Legionnaires is caused by Legionella bacteria which usually lives in lakes and streams but occasionally this bacteria can get into man-made water systems growing out of control in cooling towers fountains and plumbing systems they even thrive without many nutrients and conform slimy clusters called biofilms that help them resist disinfectants this lets them grow better than other bacteria and man-made systems from there the bacteria can become airborne in tiny water droplets which can spell disaster for unlucky humans that inhale them Legionella takes hold in lung cells multiplying and killing them which causes fevers difficulty breathing lung failure and even death five to 25% of the time Legionella is specifically problematic in places like hospitals when people are already sick their immune systems can't fight back as well and there are higher mortality rates oddly Legionnaires disease seems to be on the rise in the United States rates of the disease have increased more than 400 percent since 2000 reaching over 6,000 cases in 2016 but the CDC stress is that this might be because of more awareness and reporting despite our best efforts Legionella keeps popping up in unexpected places including decorative fountains grocery store produce misters hot tubs and even potting soil thankfully many cases of Legionnaires disease respond to antibiotic treatments and there have been some efforts to develop a vaccine so just make sure the hot tubs are properly chlorinated before you soak cysticercosis is a parasitic infection that's caused by swallowing tapeworm eggs the eggs hatch in your small intestine and then burrow their way into other organs where they camp out and form cysts the severity of this infection can vary a lot cysts and muscle tissue may cause no symptoms or just a slightly sore lump but they can also form in the eyes brain and spinal cord which can be debilitating or deadly between 2003 and 2012 there were over 18,000 hospitalizations in 42 states for cysts in the brain called neurocysticercosis most were reported in California and Texas however it's hard to tell how many people got infected in this state where hospitalization happened or even the United States in general it can take months or even years after ingesting tapeworm eggs before any symptoms develop thankfully cysticercosis seems to have a relatively low mortality rate one study found that from 1990 to 2002 there were only 221 deaths and oddly in many says the cysts go away on their own which is good news because they're tricky to treat there are drugs that can help destroy cysts but the inflammatory response from that can be worse than the symptoms brain surgery to remove them is also risky so mostly washing your hands is a simple and important way to protect yourself the final disease on this list is the most rare there were only 34 cases reported in the u.s. between 2008 and 2017 but it's also the most dangerous with a mortality rate of 97% the critter to blame is the brain eating amoeba also called Naegleria fowleri this amoeba likes to live in warm freshwater and infection occurs when swimmers get water up their noses the amoeba Wiggles its way into the brain and releases molecules that destroy brain cells and cause severe swelling this usually deadly infection is called primary amebic meningoencephalitis because an fowleri infection is rare some people had assumed that the amoeba was fairly rare in the environment but that doesn't actually seem to be true originally we thought it thrived in southern states with reports of disease from California to Florida but more recently there have been cases as far north as Minnesota Plus researchers have found to the amoeba and recreational lakes in Arizona and reservoirs in Texas and even treated water systems in Louisiana in fact since 2008 four people have died in the u.s. because of contaminated tap water the biggest mystery is why hundreds of people can swim in an infected Lake and stay totally healthy while one unlucky person will contract the illness so it's hard to know what to do to stay safe because treatment options are scarce there's only one antimicrobial that may help infected patients the CDC recommends using boiled or distilled water for nasal rinses and limiting how much water goes up your nose while swimming in fresh water or you know you could just head to the ocean and fowleri can't survive in salt water although these diseases are definitely scary they're all pretty rare like if it's any comfort you're much more likely to die from lightning than from the plague but knowing what's out there we could all be a little more careful thanks for watching this episode of scishow which is produced by complexly if you want to learn more about the complex things that can affect human health in the unite States check out our sister channel healthcare triage at youtube.com slash healthcare triage


  1. are we not gonna even talk about rabies?? literally the deadliest virus to ever exist? that makes marberg look like a rhinovirus? like 99.9% mortality rate once symptomatic? theres only been like 3 or 4 reported cases in human history of someone being infected and living

  2. The ameoba is super common, infection is very rare though as the human is simply a mistaken food source for the ameoba, plus you have to get water VERY far up your nose in order to even pose a risk

  3. I don't understand.
    "Sin Nombre" translates to "Nameless" or "No Name".
    But the virus is named the "Sin Nombre Virus".
    So which is it? Is it nameless or not?

  4. The lake near where I grew up had Naegleria outbreaks every few years. For some reason the out breaks were more likely when the water level dropped and an invasive species of water plant would grow and almost choke out the lake. People learned to not swim when that plant was present.

  5. Oh, great, just started the video and so far BOTH of the first two diseases mentioned…are in my home state! Yikes.

  6. I just want to mention Creutzfeldt–Jakob disease, which is a prion. There are approximately 1 in a million cases globally per year and it can be acquired, be hereditary…or you just get it…for no reason, just, boom prion (Which is the most common way. 87% of cases are sporadic). It has a 90% Fatality rate within 6 months but a 100% fatality rate eventually, with degenerative conditions such as dementia, memory loss and personality changes along the way.

  7. Poor girl! She can barely finish a sentence without running out of breath! Maybe she is being forced to voice this video and is signaling for help with the implied "so there" after each fact. Bless her heart.

  8. "More likely to die from lightning than the plauge"

    Depends. I never go outside, so my chance of getting struck by lightning is zero!

  9. Go to salt marine water & find Vibrio Vulnificus, possibly the most virulent bacteria known, it explodes in high Iron environments, once it finds it's way into your blood system it can literally kill you in a few days due to Blood Sepsis (blood poisoning). Humans are not evolved for the water, do as I do and stay out of it, fresh or salty (I've Hemochromatosis, I'm particularly susceptible), we are not marine creatures.

  10. I knew it! I detest those produce misters because I figured they're probably not cleaned properly and just begging to spread Legionnaires' disease. Plus they make the lettuce sopping wet and icky.

  11. man, she perfectly hits the same 3 pitches when starting, mid explanation and at the very last word of a sentence. it's ridiculous XD

  12. It's importantto remember that Legionnaire's/Legionella is mostly dangerous to people with already compromised immune systems – smokers, old people, people who take autoimmune suppressants for conditions like Crohn's, or people with AIDS are some of the people most likely to get the disease. It's named after the outbreak where it was discovered, at a Legionnaire's Convention, and it does not transmit person-to-person frequently IIRC, especially since it has a hard time infecting people with healthy immune systems.

  13. please get someone else to voice these, no offense but the way she talks is really annoying… the girl from scishow space would be a much better fit!

  14. An excellent, carefully researched, and very refreshingly non sensationalist video, quite a rarity here among YouTube 'science videos'! However, although the role of potting soil as a source and 'culture medium' for Legionella was mentioned, recent research indicates that the importance of this material as a source for Legionella infections has been underestimated, and multiple outbreaks traceable to potting soils ('composts' in the UK) have occurred in recent years in the UK. The same sources listed, plus both freshwater and marine aquaria, and housing and holding facilities for fishes, amphibians, and aquatic reptiles are also sources of Human infection with opportunistic Mycobacterium infections. The cooling systems of water cooled welding and autoworker's equipment commonly become colonized by mycobacteria, and the aerosols generated by such colonized equipment frequently lead to sensitization and inflammatory responses among Humans using them for extended periods of time.

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