Contagious Cancer Is Spreading Through American Waters

Kind: captions Language: en Cancer. Few words inspire more fear. At best, it means a brutal fight for survival. At worst, a slow and painful death. But, there's always been one reassuring fact: cancer isn't contagious. It doesn't spread like a virus. It's caused by mutations that turn our own cells against us. Or at least, that's what we thought. Deep inside a North American reservoir, scientists noticed a mysterious disease spreading through the local catfish population. At first, it looked like an infection or a strange skin disorder. The truth was far more disturbing. At first glance, Lake Memphremagog looks just like another border lake. [music] The glacial lake stretches more than 30 miles into Quebec, with most of its water in Canada, even though most of its watershed lies in the United States. But, beneath the surface, Memphremagog was hiding a disturbing secret. In 2012, fishermen started to pull up fish covered in strange, raised, black bumps. The growth looked like the unmistakable sign of disease, raising fears that the fish might not even be safe to eat. Anglers stopped fishing the lake, and the biologists came flooding in. At first, the scientists focused their efforts on the more likely scenarios, the most obvious being pollution. Lake Memphremagog was known to be a heavily polluted lake. Not only did it have the regular sediment expected in a freshwater lake, but it was corrupted with accumulated phosphorus. It wasn't exactly a healthy environment for fish. Then came Hurricane Irene in 2011. It dumped heavy rainwater from around the region into the lake, causing major flooding and introducing foreign pollutants into it. And as the scientists investigated, the problem kept growing. By 2014, the mystery had turned into a plague. The number of fish with the strange black spots on their body was growing, >> [music] >> and so too was the size. Strangely, it only affected one species, the brown bullhead catfish. The lake was still considered overall safe to fish, but this had turned into a large-scale medical and scientific mystery. A polluted lake producing weird mutations. No one knew how bad it was going to get, especially once they discovered the truth. It would take over a decade and what the scientists discovered would create a panic. By 2026, the number of catfish that were manifesting these symptoms had risen to over a third. [music] The panic only increased when the cause of the strange lesions was revealed, skin cancer. Specifically, a type of melanoma found in fish including brown bullhead catfish. However, this condition was usually fairly rare. This was by far the highest prevalence of the disorder ever found in a fish population. They had the answer and now they needed the cause. A cancer plague changed the conversation. This isn't just a concern for fishermen anymore. Was there something in the water of Lake Memphremagog that was mutating these fish? The first suspect was the water itself. The pollution was well known, but the recent flooding and the higher levels of phosphorus could have accelerated the problem. If the water was becoming toxic to fish, how long until it became toxic to humans? The situation was reaching a crisis point. As the study of the catfish population continued, it became clear this was becoming an epidemic. The fish were displaying an infection rate that was only getting higher. Whatever this was, it was escalating fast. The phosphorus that was poisoning the lake was agricultural runoff, introducing a high level of organic toxins into the water. This meant the slurry in the lake started to produce a potential for novel infections like the one showing up in the fish. But melanoma wasn't new and typically it doesn't spread this fast. Now researchers shifted their focus from studying the lake's makeup to studying the fish that were carrying it. And it wasn't long before something bizarre emerged. They compared the cancer cells from the catfish with samples of healthy catfish DNA. While the DNA changed from sample to sample, the cancer cells didn't. No matter which catfish had the cancer, it didn't seem to be different in makeup. The catfish weren't developing the cancer, the cancer was finding each catfish. That's when scientists knew something truly strange was going on here. The disease was only found in the Vermont portion of Lake Memphremagog and Village Pond in New Hampshire. That meant the fishes behavior in this lake might provide a clue. Brown bullheads have a spawning season like most fish, and they tend to cluster together in the water at that time. This creates a situation where infection spread incredibly quickly, and they can poison a full population. The circumstances were right for a fast-spreading skin plague, but cancer isn't supposed to spread, or is it? Cancer isn't transmissible among humans, at least it never has been until now. It's typical in nature that the deadliest diseases aren't the most transmissible. Nature doesn't want to kill everyone off with a virus, it wants the virus to spread and evolve, but cancer works differently, turning the body's own cells against it and then crowding out the healthier cells. Cancer isn't an invasion, it's a civil war. We live in a more polluted world than ever before, and the types of pollutants we're surrounded by are more varied. Fossil fuels and energy byproducts are commonplace, and the current influx of data centers has many people worried that the increase in pollutants could wreak havoc on the immune system in unpredictable ways. So, any mutation in the way diseases function has people on high alert because this could be a crisis in the making. Now, scientists are looking toward the animal kingdom. The types of cancers humans get aren't transmissible, as they're entirely contained to the mutations of our own cells. But, those cells also exist in animals. >> [music] >> Because they interact with each other in ways that no human would ever think to, there's a level of exposure that can cause those cancer cells to leave the body and find hosts in other animals. In some cases, it can be life-threatening. Hamsters might seem like adorable pets, but they are known to be fairly combative with each other, as well as engaging in some disturbing behavior such as cannibalism. And that's the behavior that's introduced a plague into their community. Some Syrian hamsters are vulnerable to tumors, having unsightly growths over their bodies. When the other hamsters attack, or the hamster gnaws on its own tumors, the cancer has been seen to spread. This has been observed in laboratory populations so far, with the disease seeming to spread aggressively between hamster populations that are in close contact. But, the spread stops when they're separated. This kind of direct contact transmission of cancerous tumors is rare, but it's not unheard of. Even man's best friend isn't safe. Canine transmissible venereal tumor is a relatively minor cancer that forms on the genitalia of both male and female dogs. One of the strangest things about this cancer was that it seems to appear in only two places, the genitalia and the nose. That's because dogs were gnawing or sniffing at their tumor, thus picking up the cancer cells and causing an infection in that area, which can cause nosebleeds and other issues. This caused it to jump from dog to dog. [music] The result was an infection traveling from one dog's private parts to another dog's face. These transmissible cancers are all caused by one source, [music] but another case has biologists far more worried. All of these cases of cancer transmission happen when an animal bites another sick animal and willingly ingests the cancer, introducing it to its own bloodstream. But, in the case of much more primitive animals, there's an indication that cancer can be transmitted without direct body-to-body contact. This is common in mollusks because of the unique process that the body goes through when they die. Their death process releases a large amount of fluid from the hemolymphatic system, essentially their blood, and the rest of the mollusks are the targets. This phenomenon was first observed in soft-shell clams, where the population proved vulnerable to what was essentially a clam form of leukemia. But, shockingly, this wasn't just the nearby clam bed that was found to be infected. Clam beds hundreds of miles away had the same cancer. That meant the cancer was being spread on the tides and surviving long enough to infect other clams far away. This was the first concrete proof of a cancer that wasn't just transmissible, but able to transmit itself independently. Across the oceans, transmissible cancers have been found in marine bivalves. In the strangest case, the golden carpet shell clam was found to have a novel cancer for its species, and instead the cancer had first been detected in the pullet carpet shell, a bivalve of a completely different species. This was the first case detected of the free-flowing cancer jumping species through the ocean and infecting a totally different species. Now all eyes are on the waters of Lake Memphremagog. Scientists now knew that cancer jumping from one animal to another or even one species to another was possible. During spawning, the fish gathered in shallow water allowing physical contact that could transmit the tumor cells. The catfish are considered to be a barometer of water quality. Catfish in poor health means the water quality might be unsafe. So the first thought was an infection or maybe a virus, but once the result of melanoma came in, the mystery deepened. The condition is common among humans and it's generally a treatable cancer if found early, but it is heavily associated with sun damage. But brown bullhead catfish are bottom dwellers living their lives deep under the [music] water far away from the sun. Yet they weren't just getting melanoma, they were riddled with it. The researchers did a deep dive into the genetic code of the fish, not just the cancer cells. The initial working theory was the polluted water had led to mutations in the fish making them far more susceptible to cancerous growths. This would bypass the need for sun exposure to make melanoma more common and it would match up to other cases where the environment wreaked havoc on the immune system of the animal. As the lake was only getting more polluted, the frequency of the mutation would continue to increase. It was a good guess, but it was dead wrong. The scientists found out that the genetic code of the catfish was essentially normal. They had been exposed to plenty of pollution, sure, but it hadn't affected their genetic code. The individual flesh of the catfish away from the affected area was healthy. By contrast, [music] the DNA of the tumors was almost identical. Each catfish hadn't developed its own tumor. It was sharing a nasty, fast-growing melanoma that was [music] infecting all of them through unknown means. By this point, the infection rate was approaching 40%. [music] If up to 40% of people in a major city suddenly started developing unsightly skin growths, it would be impossible to avoid. Over one in every three people you meet would be carrying the plague on their face. And here, the fishermen were pulling in more and more fish with these strange growths every single day. But the source was in the water. As the researchers dug into the infected populations data, they noticed some unique statistics. For one thing, the cancer only seemed to occur in larger catfish that were of mating age. That backed up the theory that the spawning behavior, which involves close quarters mating, was a disease vector. Another important data point, and some good news for the fish, was that the cancer didn't seem to be a fast-developing one. The fish that were infected could live on for years with the unsightly tumors without it impacting their quality of life. But that may just be making the problem worse. The population of cancerous catfish is growing, and they keep on returning to the same spawning grounds of Lake Memphremagog every season. While they eventually depart, the cancer cells don't. Because if there's one thing the scientists want you to take away from the case, it's that these cancer cells aren't like the ones that develop in our own body. They are not fast-reproducing cells that turn the body against itself. They are self-sustaining cells that are looking for a new host, and the water is filling up with them. And they can wait. The current theory is that each season the fish [music] come to the lake spawning grounds where they shed skin cells into the water, and the cancer cells go with them. While the skin cells sink to the bottom, the cancer cells don't. They continue to exist in the water like a microscopic immortal jellyfish that just waits for a suitable host that it can burrow into, spreading over and over again. Because the cancer doesn't kill its host like some melanomas do, the next generation of hosts can continue the cycle. This has many laymen wondering, are we next? If a cancer is starting to become transmissible, people are naturally worried that the next mutation would be allowing it to jump from fish to person. After all, humans are drinking water from the lake, and some are eating the fish that come from it. The governments have said that the water is safe to drink, and they haven't issued a stop fishing order, although the infected brown bullhead are becoming persona non grata in the catch. All the scientists have said there's no risk of transmissible cancer to humans, and they're right, except in the most bizarre circumstances. While it's not a regular occurrence, there have been cases of cancer being transmitted from one person to another. The majority of the cases were due to organ transplants, where a cancerous organ or tissue was implanted in a healthy person. This meant the cancer cells were able to find a new host. This wasn't a natural occurrence, and it's led to better screening of donated organs for cancer and other diseases. Additionally, some cancers are caused by viruses like Kaposi's sarcoma, and those are harder to protect against. But one case showed just how bizarre the human body can be. When a man in Colombia died of a mysterious condition after coming into the hospital with infections comorbid with HIV, he was also found to be ravaged with cancer. >> [music] >> But the cancer wasn't normal human cells, and after years of investigation into his case, it was found that the cells belonged to the dwarf tapeworm. The tapeworms had developed cancer, and due to the man's seriously weakened immune system, they were able to infect him next. It was a bizarre medical mystery that was only able to happen because of how sick he was. So, the average person should be safe, for now. We're not going to catch cancer from a catfish. That much is clear. But the disturbing mutations within Lake Memphremagog point to a bigger concern. The slurry of phosphorus and agricultural waste within the lake has created an environment where an unknown transmissible cancer can flourish. It is threatening an entire population of fish, and spreading faster than it can be contained. Around the world, people are looking at the environment and wondering, are we just waiting for the next strange mutation caused by toxins to affect us? This cancer isn't likely to get us, but we all know how vulnerable we are to a novel virus. Check out New Evidence Reveals New Important Details About COVID-19 Origins for the Declassified Details on the virus that shut down the world, or click on this video instead.