They’re invisible, unpredictable and everywhere.
Most are harmless — some even helpful — but a few are the stuff of nightmares. These creepy microbes infect, invade and control their hosts, earning them a well-deserved place in the hall of scientific horrors. Here, in no particular order, are some of the spookiest pathogens known to science.
Flesh-eating bacteria
The name speaks for itself. These terrifying bacteria cause necrotizing fasciitis, a serious disease that spreads rapidly from the onset. Staph bacteria, Vibrio vulnificus and methicillin-resistant Staphylococcus aureus, or MRSA, are the cause of most cases. Symptoms include dark red or purple discoloration of the skin, swelling, severe pain, fever and vomiting. Despite being called “flesh-eating bacteria,” the bacteria do not actually consume human tissue. Instead, they produce toxins that lead to tissue death. If they enter the bloodstream, the mechanisms that help you fight an infection will react in a dangerous way that leads to organ failure, tissue damage and, in some cases, death.
Brain-colonizing fungus
Meet Cryptococcus neoformans, a tiny fungus that can enter the bloodstream after being inhaled. It bypasses the body’s defenses to infect the brain in individuals with compromised immune systems. If it succeeds, it can cause a life-threatening brain infection called cryptococcal meningitis, leading to headaches, confusion and hallucinations. In severe cases, the fungus forms clusters of cells that grow in the brain tissue. Found in soil and pigeon droppings, the idea of an organism colonizing your mind is enough to make anyone’s skin crawl.
Brain-eating amoeba
If there’s one microscopic pathogen that earns its horror-movie reputation, it’s the brain-eating amoeba. Officially known as Naegleria fowleri, this single-celled organism lives in warm freshwater lakes, rivers and hot springs. When contaminated water enters the nose, it can travel up the nerve responsible for the sense of smell and straight into the brain. There, it destroys brain tissue with startling speed, causing a rare but almost always fatal infection called primary amebic meningoencephalitis. Some people have antibodies to the amoeba, indicating that they’ve been infected and survived. Nevertheless, the fatality rate is higher than 97%, even with treatment. Terrifying.
Haunted horned rabbit virus
We may be closer to real-life jackalopes than previously thought. If you’ve ever seen a rabbit with what looks like horns sprouting from its head, you’re not imagining things. The cottontail rabbit papillomavirus is one of the first DNA viruses ever shown to cause cancer. This pathogen infects rabbits and hares, producing horn-like tumors that can grow large enough to hinder eating or even lead to death.
Parasitic zombie fungus
Make way for Cordyceps. If you like apocalyptic zombie entertainment, you’re probably already familiar with this famous fungus. Don’t worry, it can’t hurt people. Insects, on the other hand, have reason for concern. Cordyceps is a fungal genus comprising more than 260 species, many of which take over and control insects. When the fungus attacks a host, its root-like structure invades and eventually replaces the host tissue, causing elongated mushrooms to grow out of the host in cylindrical shapes.
Swiss-cheese brain disease
This last one isn’t a virus, bacterium, fungi or parasite — it’s a protein. A prion is an infectious, misfolded protein that causes irreversible brain damage and death. As prions encounter new proteins, they trigger the same misfolding, resulting in a terminal condition known as spongiform encephalopathy. Over time, this infection essentially turns your brain into Swiss cheese. Prions are nearly impossible to eradicate from an environment. In fact, infected brains that have been sitting in formaldehyde for decades can still transmit the disease. After all, it’s hard to kill what’s not alive in the first place.
It turns out you don’t need a haunted house to find horror, just a microscope. These pathogens lurk in the soil, water and the air we breathe, acting as proof that the natural world is just as strange — and sometimes stranger — than fiction.
Written by: Sydney Burge