Chapter Content
Okay, so, like, have you ever thought too much about all the tiny little creatures, like, you know, microorganisms, that are all around us? I mean, it's probably not the best habit to get into, right? Apparently, Louis Pasteur, you know, the famous chemist and microbiologist, was, like, super careful about them. He'd, like, inspect every dish with a magnifying glass before eating it. Can you imagine? I bet he didn't get invited to dinner parties too often.
But seriously, you don't have to, like, totally freak out about bacteria, because, I mean, they're everywhere, right? You're covered in them, like, more than you can imagine. Even if you're healthy and, you know, pretty clean, there are, like, a trillion bacteria just munching away on your skin. I'm talking, like, a hundred thousand per square centimeter. They're eating, like, ten billion flakes of dead skin that you shed every day, plus all that, like, tasty oil and minerals coming out of your pores. You're basically, like, a warm, mobile buffet for them. And, you know, in return, they give you body odor. Thanks, guys.
And that's just the ones on your skin! There are, like, trillions more crawling around in your gut, up your nose, stuck to your eyelashes, swimming on your eyeballs, drilling into your gums. Your digestive system alone is home to, like, a hundred trillion bacteria, and at least 400 different kinds! Some break down sugars, some deal with starch, some, like, attack other bacteria. And a lot of them, like, don't seem to do anything in particular, like this one called *Enterobacter sakazakii*. They just seem to like hanging out with you. Each of us is made of, like, a hundred trillion cells, but we're hosting, like, ten times that many bacterial cells. So, yeah, bacteria are a big part of us. Of course, from their point of view, we're just a small part of them, I guess.
We humans, we're, like, big and smart, and we make antibiotics and stuff, so it's easy to think we're going to wipe out bacteria, right? But, like, don't believe it. They might not build cities or have a crazy social life, but they'll probably be here when the sun explodes, you know? This is their planet. We're just here because they let us be.
Seriously, don't forget, bacteria lived for billions of years before we even showed up. And we wouldn't last a day without them. They process our waste, make it useful again, nothing would decompose without them munching away, you know? They purify our water, they make our soil fertile, they synthesize vitamins in our guts, they turn what we eat into useful sugars, and they fight off any bad bacteria that sneak in.
And, like, we totally depend on bacteria to take nitrogen from the air and turn it into nucleotides and amino acids that we can actually use. I mean, that's pretty amazing, right? Apparently, to do that industrially, like, to make fertilizer, you have to heat stuff up to, like, 500 degrees Celsius and squeeze it to 300 times the normal atmospheric pressure. But bacteria, they just do it, like, casually, you know? So, yeah, thank goodness for them, otherwise, bigger life forms just wouldn't survive. And, like, most importantly, they're constantly providing the air we breathe and keeping the atmosphere stable. Bacteria, including, like, modern cyanobacteria, provide most of the oxygen on Earth, you know? Algae and other microorganisms in the ocean, they pump out, like, 150 billion cubic kilometers of that stuff every year.
And, like, bacteria reproduce like crazy. The fast ones can make a new generation in, like, less than ten minutes. There's this nasty one called *Clostridium perfringens* that causes gangrene, and it can reproduce in, like, nine minutes. At that rate, theoretically, one bacterium could produce more offspring than there are protons in the universe in just two days! This one biochemist, Christian de Duve, said that, given enough nutrients, one bacterial cell could produce, like, 280 trillion individuals in a day! Meanwhile, a human cell can only divide about once in the same amount of time.
And, like, every million cell divisions or so, you get a mutant, right? Usually, that's bad news for the mutant, but every once in a while, a new bacterium happens to have some advantage, like, say, resistance to antibiotics. And, like, with that, another scarier advantage can quickly arise. Bacteria can share information, you know? Any bacterium can get pieces of genetic code from any other. It's like, all bacteria are swimming in the same gene pool, basically. A change that happens in one area can quickly spread to another. It's as if humans could, like, get the genetic code to grow wings or walk on the ceiling from an insect. Genetically, it means bacteria have become a kind of super-organism, small and scattered, but, like, unstoppable, you know?
No matter what you spit, drip, or spill, bacteria can probably live and reproduce on it. You just give them a little moisture, like, wipe a counter with a damp cloth, and they'll, like, bloom out of nowhere. They can eat away at wood, the glue in wallpaper, the metal in paint. Scientists in Australia found this bacterium called *Acidithiobacillus ferrooxidans* that lives in sulfuric acid so concentrated it could dissolve metal, and it, like, needs the acid to survive! And they've found this bacterium called *Deinococcus radiodurans* that, like, chills out in the waste tanks of nuclear reactors, eating plutonium and other leftovers. Some bacteria even break down chemicals that we don't even think they get any benefit from.
And, like, they find bacteria in boiling mud pots and caustic soda pools, deep inside rocks, at the bottom of the ocean, in hidden pools of ice water in Antarctica's McMurdo Dry Valleys, and eleven kilometers deep in the Pacific Ocean where the pressure is a thousand times higher than at the surface. Some of these things seem, like, impossible to kill. Apparently, *Deinococcus radiodurans* is, like, almost immune to radiation. If you blast its DNA with radiation, the pieces almost instantly reassemble, "like the scattered limbs of an undead man in a horror movie."
And, like, maybe the toughest of all is streptococcus, which survived for two years on the moon inside the sealed lens of a camera and, like, still came back to life. So, yeah, there's really, like, hardly any environment where bacteria can't survive. Someone said that, like, when they lower probes into superheated vents at the bottom of the ocean, when the probes are, like, melting, there are still bacteria there.
Back in the 1920s, two scientists at the University of Chicago claimed they'd isolated bacteria from oil wells, like, 600 meters deep. People thought that was, like, totally ridiculous, nothing could live that deep. They thought their samples must have been contaminated. But now we know there are tons of microorganisms living deep inside the Earth, and a lot of them have nothing to do with the organic world we know. They eat rocks, or rather, stuff in rocks, like iron, sulfur, manganese. And they breathe weird stuff too, like iron, chromium, cobalt, even uranium. And that process, it might have helped to concentrate gold, copper, and other valuable metals, and probably helps with the storage of oil and natural gas. Some people even think they created the Earth's crust by, like, slowly gnawing away at things.
Some scientists think there might be, like, a hundred trillion tons of bacteria living under our feet, in this place they call the "subsurface lithoautotrophic microbial ecosystem" or SLiME. This one guy, Thomas Gold, estimated that if you took all the bacteria out of the Earth and piled them on the surface, they'd bury the planet, like, 15 meters deep, or, like, four stories high. So, if that's right, there might be more life under the Earth than on top of it, you know?
Deep down in the Earth, microorganisms are, like, tiny and lazy. The most active ones might divide less than once a century, some might divide less than once every 500 years. It's like, the key to longevity is just doing nothing. When things get really bad, bacteria just shut down all their systems and wait for better times. In 1997, scientists managed to reactivate some anthrax cells that had been dormant in a museum for, like, 80 years. When they opened a 118-year-old can of food and a 166-year-old bottle of beer, some of the microorganisms just woke up! And in 1996, scientists in Russia claimed they revived bacteria that had been frozen in Siberian permafrost for three million years! But the record for endurance is held by this guy Russell Vreeland, who claimed in 2000 that he woke up 250-million-year-old bacteria that had been trapped in salt deposits in New Mexico. If that's true, then those microorganisms are older than the continents, you know?
People were, like, understandably skeptical about that report. A lot of biochemists think that bacterial components would degrade and lose their function over such a long time unless the bacteria woke up every once in a while. But even if they do wake up, they probably wouldn't have enough energy stored to last that long. And other scientists think the samples might have been contaminated. In 2001, a team in Israel argued that the 250-million-year-old bacteria were almost identical to a modern bacterium found in the Dead Sea. There were only, like, two different gene sequences, and they were only slightly different.
So, these Israeli researchers were, like, should we really believe that *Bacillus permians* accumulated the amount of genetic change in 250 million years that can be achieved in a laboratory in just three to seven days? And Vreeland's response was that bacteria evolve faster in the lab than they do in the wild. So, yeah. Maybe.
Up until, like, the space age, most textbooks only divided the biological world into two groups, plants and animals, which is, like, kinda crazy, right? Microorganisms hardly got any attention. Amoebas were considered primitive animals, algae were considered primitive plants, and bacteria were often lumped in with plants, even though everyone knew they weren't plants. Back in the late 19th century, this German naturalist proposed that bacteria should be in their own separate group, which he called "monera." But that idea wasn't accepted by biologists until the 1960s, and even then, only by some of them. Apparently, this dictionary from 1969 didn't even recognize the name.
And the traditional classification system didn't really work for a lot of the microorganisms in the visible world either, like, right? Fungi, you know, mushrooms, molds, yeasts, they were almost always considered plants, but they really didn't have much in common with plants at all. Structurally, they had more in common with animals because they build their cells out of chitin, which is the stuff that makes insect shells and mammal claws. And fungi don't photosynthesize like plants, so they don't have chlorophyll, so they're not green, right? Instead, they just eat stuff, like, anything. Fungi can corrode the sulfur in concrete walls or the rotting stuff between your toes. Plants can't do that, you know? The only plant-like thing they have is roots.
And the classification system worked even less for this particular group of microorganisms that used to be called slime molds, but now they're called myxomycetes. And their obscurity has probably something to do with the name, right? If it sounded a little bit more exciting, they'd probably get more attention, because they're one of the most interesting microorganisms in nature, right? When times are good, they exist independently as single cells, like amoebas, but when conditions get tough, they crawl together to a central location and, like, magically turn into a slug. It's not a pretty slug, and it doesn't move very far, usually just from the bottom to the top of a pile of leaves, but over millions of years, it's probably been one of the most amazing tricks in the universe, right?
And it doesn't end there. Once the slug gets to a better location, it transforms itself again, into a plant-like form. Through some amazing and orderly process, the cells change shape, like a little marching band, and put out a stalk with a bud on top called a "fruiting body." Inside the fruiting body are millions of spores. When the time is right, those spores go off in the wind to become single-celled microorganisms and repeat the process.
For years, these slime molds were called protists by zoologists and fungi by mycologists, even though everyone kind of knew they didn't really belong to either group. And when they invented genetic testing, people were surprised to find that they were so different, so weird, and not directly related to anything else in nature, sometimes not even related to each other.
So, in 1969, this ecologist named R.H. Whittaker proposed to divide life into five main parts, or "kingdoms," which were animals, plants, fungi, protists, and monera, to sort out the increasingly inadequate classification system. Protists were originally suggested by a biologist named John Hogg to describe anything that wasn't plant or animal.
And while Whittaker's new plan was a big improvement, the meaning of protists was still not really defined. Some people used the name to refer to large, single-celled microorganisms, but some used it as a biological junk drawer, putting anything that didn't fit anywhere else in it, including slime molds, amoebas, and even algae, you know? Someone calculated that it included as many as 200,000 different organisms. That's a lot of junk.
Ironically, just as Whittaker's five-kingdom classification system was starting to get written into textbooks, this guy was about to make a discovery that would challenge everything. His name was Carl Woese, and since the 1960s, he had been quietly studying the genetic coherence of bacteria. In the early years, it was a really difficult process. Studying one bacterium could take a year. According to Woese, there were only about 500 known bacteria at that time, which is fewer kinds than you have in your mouth, you know? Today, that number is about ten times that, although it's still much less than the 26,900 kinds of algae, 70,000 kinds of fungi, and 30,800 kinds of amoebas, which are all recorded in the chronicles of biology.
The total number of bacteria isn't just low because people didn't pay attention to them, though. Separating and studying bacteria can be really difficult. Only about one percent of them can be reproduced through cultivation. Considering their strong adaptability in the natural environment, it's really weird that they don't seem to like living in petri dishes. If you drop bacteria on an agar culture, most of them will just lie there, no matter how much you fuss over them. So, any bacteria that reproduce in the lab are really just the exception, and those are the ones that microbiologists study. Woese said it was "like learning about animals by visiting a zoo."
But thanks to the discovery of genes, Woese could study microorganisms from another angle. And he realized that the microbial world could be divided into even more fundamental parts, that a lot of small organisms that looked like bacteria and acted like bacteria were actually something else entirely, something that had separated from bacteria a long time ago. Woese called these microorganisms archaea.
Now, the characteristics that separate archaea from bacteria would only excite biologists, you know? Most of them are in the different lipids or in the lack of something called peptidoglycan. But really, that makes all the difference. Archaea are more different from bacteria than you and I are different from crabs or spiders. Woese had discovered an unknown basic kind of life by himself. It was higher than the level of "kingdoms," in a place that was respectfully called the top of the world of life.
In 1976, he redrew the tree of life, including not five, but 23 main "divisions," surprising the world, or at least the small part of it that cared. He put these divisions under three new main categories that he called "domains," bacteria, archaea, and eukaryotes. So, the new arrangement was like this: Bacteria: cyanobacteria, purple bacteria, gram-positive bacteria, green non-sulfur bacteria. Archaea: halophilic archaea. Eukaryotes: microsporidia, trichomonas, flagellates, amoebas, slime molds, ciliates, plants, fungi, and animals.
Woese's new classification system didn't really cause a sensation in the world of biology. Some people dismissed his system, thinking it was too partial to microorganisms. And many people just didn't pay any attention. Woese "was extremely disappointed," apparently. But slowly, his new plan started to be accepted by microbiologists. It took a lot longer for botanists and zoologists to see the benefits. And the reason is easy to understand. In Woese's model, the plant and animal kingdoms were hung on a few little branches on the outermost edge of a branch on the main eukaryotic branch. Besides that, everything else was single-celled.
"These people have always been classifying things according to what they look like," Woese said. "The idea of classifying things according to molecular sequences is hard for many people to accept." Basically, if they didn't see it, they didn't like it. So, they stuck to the more ordinary five-kingdom classification system. Woese called that system "not very useful" and "completely misleading." "Like physics before," Woese wrote, "biology had developed to a level where the relevant objects and interactions often can't be seen through direct observation."
Back in 1998, this guy, Ernst Mayr, even declared that life should only be divided into two big categories, or "empires." Mayr said that Woese's discoveries were interesting, but wrong, and pointed out that "Woese wasn't trained as a biologist and is unfamiliar with classification principles, which is natural." For an outstanding scientist to say that was almost like saying that someone didn't know what they were talking about.
Basically, Mayr's point was that Woese's arrangement messed up the balance of the tree of life. He said that the microbial world was made of only a few thousand, and archaea had only 175 named samples, "but there probably weren't many more than that." And the eukaryotic kingdom, the complex organisms with nuclei, had millions. So, to maintain the "balance principle," Mayr thought that simple microorganisms should be put in one group called "prokaryotes" and that more complex life should be put in "eukaryotes" and given the same importance as the prokaryotes. In other words, he wanted to stick to the old classification system. The difference between simple and complex cells was the "major breakthrough in the biological world."
If we learned anything from Woese's new arrangement, it was that life really is diverse and that most of it is single-celled microorganisms that we don't really know about. It's natural to think that evolution is a long process of constant improvement, moving toward bigger, more complex things, like us. But we're just flattering ourselves. Most of the time, actual differences in evolution have always been small. It's just a fluke that we big guys came along. It's just a secondary part of the story. Out of the 23 main life forms, only three are big enough to see, plants, animals, and fungi. And even among them, some types are really small. Woese said that even if you added up all of the biomass of plants, microorganisms account for at least 80%, and maybe more. The world belongs to really small organisms, and it always has.
So, at some point, you're bound to ask, why do microorganisms try to hurt us so often? What does it benefit them to give us fevers, chills, sores, or finally, death? After all, a dead host probably can't provide a long-term and suitable environment, right?
First, we should remember that most microorganisms are harmless to human health, or even beneficial. The most infectious organism on Earth, a bacterium called *Wolbachia*, doesn't hurt humans at all, or any other vertebrates, right? But if you're a shrimp, worm, or fruit fly, you'd wish you'd never been born. One study says that only about one in every 1,000 microorganisms is pathogenic to humans, you know? That doesn't mean that the rest of them can't do bad stuff, but it makes it ok to think of them that way, right? Even though most organisms are harmless, microorganisms are still the third biggest killer in the western world, right? Even though they don't kill us, they still make us regret coming into this world.
It kind of benefits microorganisms to make their hosts uncomfortable. Sickness can often help spread bacteria. Vomiting, sneezing, and diarrhea are good ways for bacteria to leave one host and move into another, you know? And the best way is to get a moving third party to help. Infectious microorganisms like mosquitoes, because the mosquito's stinger can send them right into the bloodstream, and they can get to work before the victim's defense system can figure out what's attacking them. So, a lot of important diseases, like malaria, yellow fever, dengue fever, encephalitis, all start with mosquito bites. Luckily for us, the mediator of AIDS, HIV, isn't one of them, at least not yet. The mosquitoes metabolize the HIV sucked during the bite. If that virus figures out how to beat that, then we'll be in real trouble.
However, it's wrong to get too logical about it, because microorganisms aren't particularly crafty entities, you know? They don't care what they do to you, just like you don't care what your shampoo is doing to the millions of microorganisms you kill when you shower, right? For a pathogenic bacteria, it's also important to consider its own continued welfare when it completely destroys you, right? If they don't move to another host before they kill you, they're likely to die themselves. Jared Diamond points out that there are "many diseases that were terribly common and then disappeared as mysteriously as they appeared." He used the example of sweating sickness, which spread through England between 1485 and 1552, killing thousands of people, and then killing itself. Being too efficient isn't good for any infectious bacteria.
A lot of diseases aren't caused by what microorganisms do to you, but by what your body wants to do to the microorganisms. Sometimes, your immune system destroys cells or damages important tissues in order to get rid of pathogens. So, when you're sick, you're often feeling the reaction from your own immune system and not just the pathogens. Sickness is a noticeable reaction to infection. Sick people stay in bed, so they threaten fewer people.
Because there are so many things out there that can hurt you, your body has all kinds of different white blood cells, about ten million, each of them with the job of recognizing and destroying a certain kind of invader. It's impossible and inefficient to constantly have ten million standing armies, so each kind of white blood cell only keeps a few guards on duty. Once a certain infectious mediator shows up, the guards recognize it and send out a request for help. When your body is making that help, that's when you feel uncomfortable. And when that team finally goes to battle, recovery starts.
White blood cells are relentless and will chase every pathogen that's found until they're all gone. So, invaders use two basic strategies to avoid destruction, you know? They either attack quickly and move to a new host, like the common infectious diseases of the common cold, or they disguise themselves, so that white blood cells can't identify them, like HIV. That virus can harmlessly hide in the cell nucleus for years without being found, and then suddenly attack.
There are some weird things about infection, you know? Like, sometimes totally harmless microorganisms get into a part of your body where they aren't supposed to be, and "just go crazy." "This happens a lot in car accidents, when people get internal injuries," apparently. "Usually harmless microorganisms in the stomach will get into other parts of the body, like the blood flow, and do serious damage."
Right now, the scariest kind of uncontrollable bacterial disease is necrotizing fasciitis. Bacteria eat the internal tissue and leave a toxic, pasty waste product, basically eating the patient from the inside out. At first, the patient just feels a little bit uncomfortable, usually a rash and a hotness in the skin. But then it gets worse really quickly. And then you find that the patient is being completely eaten. The only treatment is complete surgical removal. About 70% of patients die, and many of the survivors are badly disfigured in the end, right? It's caused by the common *Streptococcus* bacteria family, which usually just causes strep throat. But sometimes, for an unknown reason, those bacteria will crawl into the wall of the throat and into the body itself, and cause the worst damage. They can totally resist antibiotics. This happens about 1,000 times in America, and nobody can say whether things will get worse.
It's the same thing with meningitis, you know? At least 10% of young people, and maybe 30% of teenagers, carry deadly meningococcus, but it lives in their throat, totally harmlessly. Very occasionally, about one in every 100,000 people will get it into their blood and get sick. In the worst case, they can die in 12 hours, it's that fast.
We could be more successful in the fight against bacteria if we didn't use our best weapon, antibiotics, so carelessly. It's important to realize that about 70% of the antibiotics used in the developed world are used in animal feed, just to make the animals grow faster or to prevent infection. So, bacteria have all the opportunities to become resistant to medicine, you know? And they take those opportunities with everything they've got, right?
In 1952, penicillin could totally fight all kinds of staphylococcus, so much so that the U.S. Surgeon General dared to say in the early 1960s that it was time to end the age of infectious diseases. He even said that the U.S. had mostly gotten rid of infectious diseases. But even when he said that, about 90% of those bacteria had already become resistant to penicillin. And pretty soon, a new kind of staph started to show up in hospitals. There was only one antibiotic, vancomycin, that could fight it, you know? But a hospital in Tokyo reported that staph had a new type that resisted that medicine too. And in a few months, that staph had spread to six other Japanese hospitals. All over the world, microorganisms are starting to win this war. In the U.S. hospitals alone, about 14,000 people die every year from infections that they got there. So it's no surprise that if drug companies had to choose between a two-week antibiotic course or a lifetime antidepressant, they'd choose the latter. Even though there are a few that have been strengthened a little, the pharmaceutical industry hasn't given us a completely new antibiotic since the 1970s.
And our carelessness is even more surprising when you realize that a lot of other diseases are probably caused by bacteria. The process of discovery started back in 1983. This doctor found that a lot of stomach cancer and most stomach ulcers are caused by a bacterium called *Helicobacter pylori*. Even though his results were easy to identify, people didn't accept that idea for over ten years because it was so radical. Finally, in 1994, the U.S. National Institute of Health accepted the idea.
Since then, there have been more studies that show that a lot of other diseases, like heart disease, asthma, arthritis, multiple sclerosis, some kinds of mental illness, cancer, maybe even diabetes, are or may be caused by bacteria. So, the days when we need an effective antibiotic that we don't have may be coming soon.
The fact that bacteria themselves can get sick is a little bit of comfort. They can sometimes be infected by a virus called bacteriophage. A virus is a weird and nasty thing, "a piece of nucleic acid surrounded by bad news." Viruses are smaller and simpler than bacteria, and they aren't living things themselves. In isolation, viruses are neutral and harmless, but if they get into a proper host, they suddenly get busy and have life, you know? There are about 5,000 known viruses, and they cause us to get hundreds of diseases, from influenza and the common cold to really harmful diseases: smallpox, rabies, yellow fever, ebola, and AIDS.
Viruses loot genetic material from living cells to make more viruses, and they grow a lot. They reproduce like crazy and then desperately look for more cells to invade. Since they aren't living things, they can stay really simple. A lot of viruses, including HIV, only have ten or fewer genes, and even the simplest bacteria have thousands. They're small, you can't see them in an ordinary microscope. And scientists didn't see them until they invented the electron microscope in 1943. But they can cause a lot of damage. It's estimated that smallpox killed three million people in the 20th century alone.
Viruses also have the amazing ability to show up suddenly in some new form in the world, and then disappear as quickly as they came. A good example is this weird sleep disease that people started getting in Europe and America in 1916, which was later called sleeping sickness. The patient would fall asleep and not wake up, right? They could be easily woken up, and they could eat or go to the bathroom, and they could answer questions, knowing who they were and where they were, but they always looked kind of indifferent. And once you let them rest, they'd fall asleep again for a long time. Some stayed that way for months and then died. And only a few survived and regained consciousness, but they weren't full of energy anymore. They were lifeless, like dead volcanoes. The disease killed about five million people in ten years, and then it quietly went away. But it didn't get a lot of attention, because there was another more terrible epidemic spreading around the world.
Sometimes the illness was called the "pig flu," and sometimes it was called the "Spanish flu," but it was really bad. The First World War killed 21 million people in four years, and the pig flu killed that many in its first four months, you know? And in World War I, about 80% of American deaths weren't from enemy fire, but from influenza, and some troops had death rates as high as 80%.
In the spring, the pig flu showed up with ordinary symptoms of a common cold, but in the following months, somehow the disease got a lot worse, right? It got to be really bad. Only about a fifth of the people had mild symptoms, but the rest got really sick and many of them died. Some people fell in a few hours, others only made it a few days.
The first American deaths were in Boston sailors. The epidemic quickly spread around the country. Schools were closed, public entertainment was shut down, and people wore masks, but it didn't do a lot of good, right? That spring, over 54,000 Americans died of the flu. There were 220,000 deaths in Britain. Nobody knows how many died globally because the Third World wasn't keeping the best records, but it was at least 20 million, probably 50 million, maybe 100 million, you know?
To develop a vaccine, medical authorities tested on volunteers in a military prison on Deer Island in Boston Harbor. If the prisoners could survive a bunch of tests, they would be pardoned. And the tests were horrible. First, the prisoners were injected with tissue from the lungs of the dead, and then their eyes, noses, and mouths were sprayed with aerosols. If they still didn't fall, then excretions from patients were smeared in their throats. If all else failed, they had to sit with their mouths open while people who were seriously sick coughed in their face.
Out of a total of 300, an amazing number, doctors chose 62 men for the tests. Nobody got the flu. Not one, right? The only one that got sick was the doctor, and he died quickly. That was probably because the flu had already been through the prison, and the prisoners had gotten a natural immunity from that attack, you know?
People don't know a lot about the 1918 flu, or anything at all. It's a mystery why it burst out suddenly in so many places with oceans, mountains, and other natural barriers. Viruses can only survive a few hours outside of a host, so how could it have appeared in Madrid, Bombay, and Philadelphia at the same time?
The answer might be that people carried it, and they only had mild or no symptoms, you know? Even during a normal outbreak, about 10% of people have the flu without even knowing it because they don't feel uncomfortable. Since they're always moving, they're probably the biggest carriers of the disease.
That might explain how widespread the 1918 outbreak was, but it still doesn't explain why the flu was laying dormant for months and then hit hard around the world at almost the same time. It's even more of a mystery that it hurt young people the most. Usually, kids and old people are the most likely to get the flu, but in the 1918 outbreak, the people who died were mainly in their 20s, 30s, and 40s. Old people might have been exposed to the disease earlier, so they had some immunity, but nobody knows why children and teenagers weren't affected, you know? And the biggest mystery is why the 1918 flu was so deadly when most flus aren't that bad. We still don't know.
Some viruses show up every now and then. This nasty Russian virus showed up at different times over large areas, but we still don't know where it went between outbreaks, you know? Some people think that the virus is hidden in beasts without people realizing it and then they reach out to a new generation of people. Nobody can say that pig flu won't show up again.
Even if pig flu doesn't show up, it's likely that other flus will. Horrible new viruses are constantly being made. Ebola, Lassa fever, and Marburg are always showing up and disappearing again, but nobody knows where they're hiding, or if they're just waiting for the chance to break out in a really bad way, you know? It's already clear that AIDS has been around longer than anyone thought. Researchers found that a sailor who died in 1959 was actually sick with AIDS. But for whatever reason, that disease was mostly dormant for the next 20 years.
It's a miracle that other diseases haven't gotten so bad. Lassa fever wasn't discovered until 1969 in West Africa. It's a deadly disease that people don't know a lot about, you know? In 1969, a doctor at a Yale lab in Connecticut got sick while studying Lassa fever, but he lived, right? But then even more surprisingly, a technician at a nearby lab, who hadn't had direct contact with the virus, got the disease, and she died.
Luckily that outbreak ended there, but we can't count on always being so lucky, right? Our lifestyle brings on infectious diseases. Air travel makes it easier to spread disease germs all over the world. An Ebola disease germ can leave Benin in Africa one day and end up in New York, Hamburg, or Nairobi in Kenya, or all three places, you know? And that also means that medical authorities need to be really familiar with every kind of disease everywhere, but that's impossible, right? In 1990, a guy from Chicago was exposed to Lassa fever while visiting his hometown in Nigeria, but he didn't show symptoms until he came back to the U.S. He died undiagnosed in a Chicago hospital. Nobody took preventive measures while treating him because nobody knew that he had one of the most deadly and contagious diseases in the world, you know? Miraculously, nobody else got the infection. We might not be so lucky next time.
So, yeah, maybe we should go back to talking about the world of visible life, right?