3 Deadly Diseases You’ve Probably Never Heard Of

By Adem Lewis / in , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , /

Every year, millions of people are infected
with diseases you’ve probably never heard of. There’s tons of media coverage about things
like malaria, Zika, and HIV — all of which pose serious threats to public health. But there are many more diseases out there
that are just as deadly — yet not as infamous. They’re called neglected tropical diseases,
or NTDs, because historically they haven’t been paid as much attention as other diseases,
and they mainly affect people in tropical areas. But these days, global healthcare initiatives
are paying attention to them — working to find ways to prevent and treat these diseases. The deadliest NTD — caused by the second-deadliest
parasite in the world, after malaria’s — is schistosomiasis, also known as snail fever. It’s caused by a parasitic worm, called
schistosoma, that’s transmitted through water that’s been contaminated with the
parasite’s eggs. The parasites use certain kinds of snails
in the water as hosts, to grow and multiply. Eventually, the parasites’ larvae are released
into the water, and that’s when anyone who comes in contact with the water is at risk,
because the larvae can burrow through the skin. Infected people often don’t have symptoms
for the first month or two, though they can sometimes end up with a rash or other symptoms
like fever, aches, and a cough. Symptoms are much more common later on, once
the larvae have grown into adults and laid eggs. That’s when the infection is considered
chronic. But the symptoms of chronic schistosomiasis
aren’t caused by the full-grown worms — the worms can actually incorporate proteins from
the host to trick the immune system into ignoring them. It’s the eggs that cause an incredibly strong
immune response, which can strike almost anywhere: the intestines, the lungs, the bloodstream,
even the brain. So schistosomiasis can cause all kinds of
symptoms, from diarrhea to wheezing to seizures. More than 200 million people have schistosomiasis
right now, and about 200,000 people die from it every year. The main way to treat it is to prevent it:
if people are regularly given a drug called praziquantel, even if they don’t have the
disease, they’re less likely to develop a severe infection later on. But the best way to protect people in the
long term is to make sure communities have access to sanitation and safe drinking water,
to stop the parasite from spreading. Another neglected tropical disease is Chagas
disease. It’s most prevalent in Central and South
America, where about 8 million people have the infection, and about 10,000 die from it
every year. Chagas is caused by a parasite called Trypanosoma
cruzi, a single-celled protozoan. The parasite spreads through the feces of
infected insects, often known as kissing bugs. Usually, the parasite enters the body through
mucous membranes — like in the eyes and mouth — or through broken skin, when someone
scratches a kissing bug bite. The best time to treat the disease is just
a few days after infection, but most people don’t show any symptoms for weeks. And even in those who do, the symptoms are
pretty mild and nonspecific — like fever, a rash, and diarrhea. And then something frightening happens: After
this initial phase, Chagas infection usually goes dormant — for years. After as much as a decade or two, about 30%
of infected people then develop chronic, life-threatening symptoms — including swelling of the heart,
or the intestinal tract. So, prevention and early detection are very
important here. But as with other NTDs, it often affects people
who don’t have easy access to healthcare. Fortunately, efforts are underway to help
those at risk, mainly with the help of insecticides. If you kill the bugs, they can’t spread
the disease. Then there’s African trypanosomiasis, otherwise
known as African sleeping sickness, which affects parts of sub-Saharan Africa. Like Chagas, this disease is caused by parasites
carried by insects — in this case, by the bite of the tsetse fly. In the first phase of sleeping sickness, the
parasite reaches the peripheral nervous system — the nerves that aren’t part of the brain
or spinal cord. Here, symptoms include things like fever,
joint pain, and itching, which can be caused by lots of different things. So — again like Chagas — sleeping sickness
is hard to diagnose at first. But symptoms become more severe when the parasite
invades the central nervous system — the brain and spinal cord. Then, it can cause convulsions, confusion,
and the symptom that gives the disease its name: uncontrollable sleepiness. If left untreated, sleeping sickness can be
fatal. But it is treatable with combined medications,
even in the second stage. And initiatives to treat sleeping sickness
have become more and more successful in recent decades. In 1995, there were an estimated 300,000 new
cases of African sleeping sickness. But since then, health organizations have
been working on testing people for the disease and getting treatment to those who need it. They’ve also been using insecticides to
kill tsetse flies. By 2014, there were fewer than 15,000 new
cases of sleeping sickness. There are lots of other NTDs out there as
well. But they aren’t being neglected anymore,
either, and that’s making a big difference. Thanks for watching this episode of SciShow,
which was brought to you and sponsored by Bill Gates. Visit GatesNotes.com to learn more about neglected
tropical diseases and how people around the world are working to fight them — like the
Uniting to Combat NTDs Coalition, which recently set the world record for the most medication
donated in 24 hours, with more than 200 million doses donated to prevent and treat NTDs.

100 thoughts on “3 Deadly Diseases You’ve Probably Never Heard Of

  1. The two first ones are quite known in Brazil, schistosomiasis = "esquistossomose" or "xistose" and chagas is just "doença de chagas". We study them at elementary school, how they are transmitted and how to prevent them.

  2. When people say Vegan Gains' wife isn't doing anything, but he's actually made this video happen. Thanks, Bill Gates.

  3. +scishow wow you broke tsetse fly with that pronunciation, but your American.
    I'll forgive you…

    You don't know how to clap you tung.

  4. I went into this feeling confident, thinking I'd be knowledgeable enough to go "Ha! I have heard of these!" when I heard them.

    ….And now I pay for my arrogance because I had no idea about the first one…

  5. This is an inaccurate description of the sleeping sickness. (ie: insomnia and periods of manic activity are part of the symptoms)

  6. Have you heard about the vaccine for schistosomiasis patented kind of recently? The researchers are still working on it, but it might have a lot of potential.

  7. Huh, as a brazilian I never knew they were neglected on american media. Those are pretty mainstream diseases here, if you've been through high school. Makes sense they wouldn't be well known up there though.

  8. I see that no one here is complaining about how much Hank is moving his hands and head/gesturing….curious.

  9. Why is Israel allowed to develop disease weapons, that's just one of evil programs, do one on operation talpiot, or technion. Use of banned weapons on civilians in own country, arming, protecting, and treating ISIS. Science should be used to help folks, not destroy lives and cause misery and death, these diseases could be wiped out like others. Interesting.

  10. When speaking about Sleeping Sickness, it would have been nice if you mentioned the other huge deleterious effect it has on people in Africa: it heavily affects livestock, meaning that conventional agriculture is very hard on them. Most people have to plow their land by hand because they can't keep oxen alive long enough to be useful.

  11. I have actually heard of all of these diseases!!!! Although I'm not sure if that's because I enjoy freaking myself out with having tropical diseases despite the fact I live nowhere near the tropics or because my roommate was pre-med….

  12. Why are there so many horrible diseases in the tropics compared to the more temperate regions of the world? It ain't fair!

  13. i new about the kissing bug and the sleeping sickness, not the first one though i wonder what the world be like if nobody ever had a disease ?

  14. thx for this ha bisky vid and the whole just not getting NTDs tell that to your brother who got one it doesnt work like that but i am not remotely worried about them its like worrying about dengue and doing something stupid and poisoning yourself with bug spray chemicals over something that is extremely unlikely to happen if you avoid places you arent supposed to go to you will be fine

    allie wes trippy didnt quite understand the curse of the volcanoes she was on the places that are so called cursed just means its very likely you will get sick there and its unknown why well we know why thats where the misquotes with dengue congregate

    if there is a story about why you shouldnt be somewhere listen to that warning it doesnt nessisarily mean you will get sick if you trespass but there is probably a chance you will get hurt or sick

  15. its partly thanks to WHO, MSF, Bayer and sanofi-aventis who contributed for the reduction of cases of sleeping sickness and chagas disease, Bayer and sanofi-aventis donated medicines and money to WHO and MSF, they even open the patent for the eflornithine(the medicine used to cure the sleeping sickness)for WHo so that they can find other pharmaceutical companies willing to make it and sell it at a low price….

  16. My university is doing research on schistosomiasis vaccines, where one can be infected by just a few male parasites so they can't reproduce. The reward for participating is quite high so I'm considering it.

  17. Chagas sounds right out of plague inc. The symptoms were pretty mild so I never paid attention to them. Then, suddenly, everyone's organ's failed.

  18. I had no idea that Chagas wasn't well known worldwide. In Brazil it's a really scary disease, especially because you could have been infected and have no idea.

  19. If your boy Bill has got your back financially then I don't think there's a need for a patreon. But I understand that's what's hip now.

  20. Schistosomiasis can also be caught by eating meat that's contaminated right? And not fully cooking it? We learn that in school here in Brazil, and I remember being quite afraid as a kid, specially at Chagas disease, my family has a farm and I was always afraid that I would be bitten by the bug and would get it…

  21. Another important way to combat Schistosomiasis is to be sure that you only buy farmed cichlids for your aquariums. Some species of cichlids eat the snails that carry the schistosomes, so when their numbers in the lake go down, the snail and worm populations go up. More cichlids in the lake also mean more tourists in the area to see the pretty fishies, bringing more money that they spend with the people who live there. More money means better access to necessities like medicine to treat people who are already sick and less need for a quick financial fix- like fishing cichlids out of the lake to sell to fancy westerners who like pretty aquariums.

  22. 99 dislikes and 9k likes 3 things 1 that's the best like to dislike ratio I've seen 2 both nines 3 pls don't dislike just don't

  23. Sooooooooo……. I'm beginning to think there is a reason why we don't discuss these. 🤢 I can't handle this much anxiety and I'll probably never visit a rainforest in my lifetime 😫

  24. Hey, awesome video but I thought I'd just let you know you pronounced "tsetse" wrong. The first 'e'-sound is a short 'e' not an 'ee'. ( if I'm explaining it right.. just Google it)

  25. My great Grandmother died from chagas and my grandmother is currently battling with it. Its weird because we are brazilian but my grandmother caught the disease here in Texas.

  26. It is unbelievable to me how many of the people on this planet do not have access to clean drinking water and do not even know about hand washing and basic hygiene. 🙁

  27. Currently completing a laboratory program, and to my surprise I know all of these. All of these diseases are terrible and mostly caused by lack of sanitation. Living in the US makes these diseases rare, but I would love to see them in action and find a smarter way of treating them in other parts of the world.

  28. This reminds me of the Hey Arnold movie where his parents presumably died trying to save a mysterious people with a mysterious sleeping disease that was even killing off fauna like butterflies. 90's cartoons were savage.

  29. I feel like a video about the evolutionary advantage/reason behind sicknesses and ailments killing the thing they are "infesting" would be an interesting topic for a video. Anyone with me?

  30. I think I have African Sleeping Sickness, I can sleep where ever I want, whenever I want, and I'm always sleepy, though I'm not a teenanger anymore.

  31. just wait… after most of them have been killed, the tsetse fly will be recognised as an important part of some ecosystem.

  32. You know you are from a third world country when all those diseases were part of the basic high school biology curriculum.

  33. Melarsoprol is used for 2nd stage sleeping sickness and nicknamed Arsenic in Antifreeze as it is made from Arsenic and is poisonous to begin with and kills about 5% of those who take it.. It also causes Encephalopathy in 5-10% of cases and in those it kills 40-50%!!It's some really nasty stuff but the only known cure for 2nd stage sleeping sickness!!!

  34. So this was sponsored by the same guy who wants to kill half of the human race with vaccines?
    I trully believe you and have trust in you guys! (sarcasm)

  35. Funny how Bill Gates or the Bill and Malinda Gates foundation is so interested in these tropical diseases. Perhaps anyone that reads this, should look into as to why. But be ware, the truth is shocking.

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