Posted on: December 17, 2019 at 5:53 pm
Last updated: July 13, 2020 at 5:40 pm

Every year as the temperature begins to drop, discussion surrounding cold and flu season starts to rise.


Preventing the spread of germs is a constant battle from October to March, and there is one sentiment you hear echoing off the walls everywhere you go: wash your hands.

One science teacher decided to conduct an experiment to show her class just how disgusting germs are, and how important lathering up really is.


An Eye-Opening Experiment

Jaralee Annice Metcalf’s photos of a science project she did with her class have now gained over 59 thousand shares and over 8 thousand comments [1].

The experiment involved five pieces of ordinary white bread. One piece was touched with unwashed hands, one with sanitized hands, and one with hands washed with warm soapy water. There was a fourth, untouched slice as the control piece, and a fifth piece was rubbed on all of the chromebooks they had in the classroom [1].

The results were illuminating… and disgusting. Each of the pieces of bread (even the one touched with sanitized hands) grew significant amounts of mould over the course of three weeks except for one: the one touched with washed hands [1].
“If the bread had been exposed to air and moisture, the experiment may have gone faster,” Metcalf told “The breads that were very clearly exposed to different germs grew mold quicker. And ones touches by clean hands plus the soap and water ones were not exposed to the germs that cause the mold growth to quicken.” [1]

Flu Outbreak in the United States

Flu season starts in the United States in October and can continue as long as May. Although the flu virus does circulate year-round, flu activity tends to peak between December and February [2]. 


There are four types of influenza viruses: A, B, C, and D. The types that humans are concerned with are A and B, which are the ones that cause seasonal epidemics every winter [6]. Influenza C is usually just a mild respiratory illness that does not cause and epidemic, and D is predominantly found in cattle [6].

The flu can spread rapidly, and 2017-2018 flu season was one of the deadliest on record. The Centers for Disease Control and Prevention (CDC) estimated that more than 900 000 people were hospitalized and more than 80 000 people died from the flu that year [3].

The 2019-2020 flu season is already well underway, and so far the CDC estimates that there have been at least 2.6 million flu illnesses, 23 000 hospitalizations, and 1300 deaths due to the flu virus [4].

How Does the Flu Spread?

Most flu experts agree that the flu virus spreads mainly by droplets of water made when someone with the flu coughs, sneezes, or talks. These droplets make it into the mouths, noses, and can even be inhaled into the lungs of people nearby. You can also get the flu by touching a surface that has the flu virus on it, and then touching your mouth, nose, or eyes, however this is much less common [5].

The trouble with the flu is that you can spread the virus before you even realize you have it. While you are typically most contagious in the first three to four days after the flu starts, you may actually be able to infect others one day before symptoms develop, and five to seven days after you become sick [5].

Some people, especially children or people with weakened immune systems, can remain contagious beyond the seven-day mark [5].

How To Wash Your Hands Effectively

We’ve established that the number one way to prevent the spread of germs this cold and flu season is to wash your hands, but there is a right way and a wrong way to do it. The key is to be thorough:

  • Use soap and water.
  • Scrub for at least 20 seconds.
  • Wash before you eat or prepare food and after you use the bathroom or change a diaper.
  • If you’re taking care of someone who’s sick, wash your hands before and after being with them [7].

If you can’t get to a sink for whatever reason, using hand sanitizer is the next best thing, but as we learned from Metcalf’s experiment, it is not a substitute for proper hand-washing.

Five Ways to Prevent the Spread of the Cold and Flu

Besides hand-washing, there are other precautions you can take to help prevent the spread of germs this cold-and-flu season:

  1. Cover Your Nose and Mouth. Use the crook of your elbow or a tissue to cover your nose and mouth when you sneeze or cough. That way, you won’t end up with germs all over your hands that you can spread to others [8].
  2. Disinfect Surfaces. Germs can live on surfaces for hours, so commonly-used surfaces like tabletops, doorknobs, remote controls, and toys should be cleaned with a disinfecting spray or wipe frequently [8].
  3. Take Care of Yourself. Healthy habits will help you be more resilient to colds and flus. Eat plenty of fruits and vegetables, get good sleep, and try to reduce stress as much as possible. This will keep your immune system strong [8].
  4. Stay Home. If you are sick, stay home. Likewise, if your children are sick, keep them home from school. This will prevent you or them from spreading the virus to others [9].
  5. Get The Flu Shot. Flu shots not only protect you, but they protect others around you who may be more susceptible to the illness [10].

The Disgusting Truth

As Jaralee Annice Metcalf’s students demonstrated, germs are gross. Thankfully, as their experiment also showed, we can prevent the spread of germs by simply washing our hands. So this cold and flu season, remember to take the necessary steps to keep yourself, your families and your neighbours healthy and happy.

Brittany Hambleton
Team Writer
Brittany is a freelance writer and editor with a Bachelor of Science in Foods and Nutrition and a writer’s certificate from the University of Western Ontario. She enjoyed a stint as a personal trainer and is an avid runner. Brittany loves to combine running and traveling, and has run numerous races across North America and Europe. She also loves chocolate more than anything else… the darker, the better!

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