Did you know, our hands are responsible for 80% of germs that cause illness?
This is why hand hygiene is such a big deal. You carry millions of microbes on your hands. Most are harmless, but you can pick up some that cause illnesses, such as colds, flu, and diarrhoea.
When we forget to sanitise or wash our hands, we can spread these germs to other people, or give them to ourselves by touching our eyes, mouths, noses or cuts on our bodies.
We can also pick up germs from objects, such as doorknobs and stair railings, touched by other people who aren't good hand washers. Think about all the things you touch each day and how many people may have touched them before you.
What do germs do?
Once germs invade our bodies, they snuggle in for a long stay. They gobble up nutrients and energy, and can produce toxins, which are proteins that are actually like poisons. Those toxins can cause symptoms of common infections, like fevers, sniffles, rashes, coughing, vomiting, and diarrhoea.
How do doctors figure out what germs are doing? They take a closer look. By looking at samples of blood, urine, and other fluids under a microscope or sending these samples to a laboratory for more tests, doctors can tell which germs are living in your body and how they are making you sick.
What Types of Germs Are There?
Germs are found all over the world, in all kinds of places. The four major types of germs are: bacteria, viruses, fungi, and protozoa. They can invade plants, animals, and people, and sometimes they make us sick.
Bacteria are single celled creatures that need nutrient from their environment in order to live. In some cases that environment is a human body. Bacteria can reproduce outside of the body or within the body as they cause infections. Some infections that bacteria can cause include ear infections, sore throats (tonsillitis or strep throat), cavities, and pneumonia.
But not all bacteria are bad. Some bacteria are good for our bodies — they help keep things in balance. Good bacteria live in our intestines and help us use the nutrients in the food we eat and make waste from what's left over. We couldn't make the most of a healthy meal without these important helper germs! Some bacteria are also used by scientists in labs to produce medicines and vaccines.
Viruses are a lot tinier than even single celled bacteria. They need to be inside living cells to grow and reproduce. Most viruses can't survive very long if they're not inside a living thing like a plant, animal, or person. Whatever a virus lives in is called its host. When viruses get inside people's bodies, they can spread and make people sick. Viruses cause chickenpox, measles, flu, and many other diseases. Because some viruses can live for a short time on something like a doorknob or countertop, be sure to wash your hands regularly!
Fungi are multi-celled plant-like organisms. Unlike other plants, fungi cannot make their own food from soil, water, and air. Instead, fungi get their nutrition from plants, people, and animals. They love to live in damp, warm places, and many fungi are not dangerous in healthy people. An example of something caused by fungi is athlete's foot, that itchy rash between their toes.
Protozoa are one-cell organisms that love moisture and often spread diseases through water. Some protozoa cause intestinal infections that lead to diarrhoea, nausea, and belly pain.
Most lethal bugs of all:
Nature sure has created some tiny monsters when it comes to microbes. These bugs make us throw up, ooze pus, bleed out of our eyes and cough up blood. But which take top honours (or dishonours) for being the most lethal of all?
1: Worst Flu Season – ever?
Did you know that in 1918, the flu killed between 20 and 50 million people? That year, World War I was raging so the effects of the flu virus sort of got overshadowed by the bigger, more obvious effects of bullets and bombs.
Researchers still aren’t sure why the 1918 flu virus was so deadly. Victims of the flu that year died in a gruesome way, the virus causing so much fluid to build up in their lungs so rapidly that it was like drowning.
If higher estimates of how many people died from the 1918 flu are true, then the 1918 flu is the deadliest microbe ever in a single year. Thank goodness we haven’t seen a flu bug that deadly again—but will we someday?
2: The Plague
The 1918 flu virus and HIV are the biggest killers of modern times. But back in the 14th century, the bacterium that causes bubonic plague, or the Black Death as it was also known, was the worst bug of all. In just a few years, from 1347 to 1351, the plague killed off about 75,000,000 people worldwide, including one-third of the entire population of Europe at that time. It spread through Asia, Italy, North Africa, Spain, Normandy, Switzerland, and eastward into Hungary. After a brief break, it crossed into England, Scotland, and then to Norway, Sweden, Denmark, Iceland and Greenland.
There are two main forms of the disease. In the bubonic form, the bacteria cause painful swellings as large as an orange to form in the armpits, neck and groin. These swellings, or buboes, often burst open, oozing blood and pus. Blood vessels leak blood that puddles under the skin, giving the skin a blackened look. That’s why the disease became known as the Black Death. At least half of its victims die within a week. The pneumonic form of plague causes victims to sweat heavily and cough up blood that starts filling their lungs. Almost no one survived it during the plague years.
Yersinia pestis is the deadliest microbe we’ve ever known, although HIV might catch up to it. Yersinia pestis is still around in the world. Fortunately, with bacteria-killing antibiotics and measures to control the pests—rats and mice—that spread the bacteria, we’ve managed to conquer this killer.
3: Ebola, the Bloody Virus
Some of you might have thought of the Ebola virus as the scariest, deadliest microbe you’ve ever heard of. Those of you who did so have probably seen the movie Outbreak or read The Hot Zone, which spotlighted this grisly virus.
Ebola is definitely a nasty killer. It is part of a group of viruses that, among other effects on the body, cause the blood to stop clotting. Victims begin oozing blood from their mouths, noses, internal organs, even their eyes. It kills up to almost 90% of those who get infected.
With that kind of death rate, Ebola would be the deadliest microbe of all if it was more common. Fortunately, infections by this virus are pretty rare. There have only been seven outbreaks in humans. It has killed just over 800 people since the first outbreak in the Democratic Republic of the Congo (formerly called Zaire) in 1976.
While outbreaks of this virus are rare and relatively small, Ebola is still one mean microbe.