Wash your hands ... and DRY THEM, too.

By Simon Shapiro

We're being bombarded with the very sensible advice to wash our hands constantly. It's the first line of defense against the COVID-19 virus. And it's critical to wash properly: enough soap and water, lots of friction, spend 20 - 30 seconds (sing 'Happy Birthday' twice through) etc. But even after a diligent washing, your hands are probably not perfectly clean. After a less-than-diligent washing, your hands are definitely not perfectly clean. Drying them properly should also be part of the routine, for three reasons:

1.  Drying your hands can remove some (or even most) of the residual bacteria and viruses.
2. Wet or damp hands provide an environment that's good for residual bacteria and viruses (and therefore bad for us).
3. Damp hands are more likely to transmit residual bacteria and viruses to other surfaces. 

In 2012 the Mayo Clinic published a survey of twelve studies looking at the effectiveness of different drying methods. Methods included cloth or paper towels, hot air dryers and jet dryers. (Jet dryers are the newer kind that use a strong, loud jet of unheated air).

Not all of the studies agreed with each other, but the overall conclusions are clear.

• Towels and jet dryers get hands 96% dry in ten seconds. Hot air dryers need 40 seconds to get to that level.
• We're usually in a hurry and don't take enough time to dry our hands. We spend 3-5 seconds on a towel and around 15 seconds on a hot air dryer. On average men are worse than women, and get to only 55% dryness on a hot air dryer; women average 68%. But both get to at least 90% using towels.
• All methods are very effective if used properly. 

  The takeaway advice is clear:

• Wash your hands frequently and carefully.
• Dry them thoroughly every time. 
• If you're using a multiple-use towel (as you likely are, at home), bear in mind that it's getting residual bacteria and viruses, so launder and change it frequently.

Virus VS Bacteria — Know your enemy

Viruses and bacteria are the typical things that make us sick. But what are they? The first thing to know is that you can’t see them without a microscope. The second thing to know is that they find a great home in our bodies, where they can grow, reproduce, and spread to new hosts. But in the process, most of them make us very, very sick. Bacteria rots our food, too.

What do viruses and bacteria look like?

Viruses are different from bacteria in many ways, and not all viruses look alike. Bacteria don’t all look the same either. Here are some things that make them different.

	Virus	Bacteria
Size	Smaller: 20–400 nm Need an electron microscope to see them	Larger: 200–1000 nm See them with a school microscope
Structure	Protein coat only, no cell	Single cell with a wall
Living/Non-Living	Between living and non-	Living organism
Reproduction	Forces host cell to reproduce its DNA	Reproduces on its own by splitting (fission)
Prevention	Fight with vaccines and hand washing	Fight with hand washing
Recovery from infection	Heal with antiviral medications	Heal with antibiotics

Images by Arek Socha from Pixabay.

How do you fight an infection of virus vs bacteria?

Viruses and bacteria that make a home in your body can make you sick. The solution for each is found right in the name: Anti-biotics fight the biotic, living bacteria. Anti-virals fight the viral infection caused by viruses. But not every virus and bacteria has a medicine to fight it.

An antibiotic cannot fight a virus, and vice versa.

Not all bacteria are killed by the same antibiotic medications.

Not all viruses are killed by the same antiviral medicines. Medicine has to be matched to the specific problem.

Amazing fact: Bacteria can catch a virus!

Some viruses can be prevented by taking a vaccine before you are exposed to the virus! Each vaccine fights a specific virus. Flu vaccines change every year to match the particular type of flu that is spreading that year, since flu (influenza) is a whole family of viruses. In Canada, most people take a group of vaccines when they are children, to prevent once-common deadly illnesses like chickenpox, measles, and mumps. When we travel to foreign places, we can take vaccines to prevent picking up viruses that are widespread there; hepatitis and malaria are common viruses that travellers get vaccinated against.

Animals get vaccinated against viruses such as rabies. Viruses and bacteria make animals sick too, but not always the same ones that make humans sick.

Your doctor will determine whether it is a virus or bacteria that is making you sick. Or it may be a different illness! They will prescribe the right medicine for the job, if that is an option.

Amazing fact: Some kinds of bacteria are good for you! Probiotics are an example of bacteria that are helpful in your stomach.

You and Your School Library Need These Books

by Helen Mason

I love reading Science books, especially those written for kids. That's because authors have to know a lot about their topic in order to distill the information into interesting and understandable communications that appeal to young readers. In the following titles, Jennifer Gardy and Tanya Lloyd Kyi make challenging scientific information readily available to young readers. These books should be in every elementary school library — and the collections of all teachers who hope to interest students in modern science.

It's Catching: The Infectious World of Germs and Microbes written by Jennifer Gardy and illustrated by Josh Holinaty (Owl Kids, 2014) uses a combination of text, visuals, and anecdotes to introduce readers to the many germs with which we share this planet.

The author, herself a disease detective, introduces past disease detectives, such as Antonie van Leeuwenhoek, the first person to see the microbial world. She explains that microbes exist both in the world around us and in our own bodies. Some of the details provide the necessary gross factor that kids love.

Without boring the reader, Grady outlines the difference between viruses, bacteria, fungi, and parasites. There's also a dangermeter for diseases that range from the common cold and influenza to malaria and ebola.

Discussing why doctors are so worried about parents who don't have their kids vaccinated against measles? Mention the 165 BCE measles plague that killed off about one-third of Rome's population. Have students of Irish descent? Suggest researching family trees to find out how many have ancestors who came to Canada following the 1845 Irish potato blight.

DNA Detective by Tanya Lloyd Kyi and illustrated by Lil Crump (Annick Press, 2015) is equally interesting. The intro draws kids right into the topic by showing a crime scene. Someone broke into a jewellery store and got away with valuable jewels. The perpetrator wore gloves. One was left at the scene. There are no other clues.

Readers will enjoy trying to pick the culprit from a list of suspects who include the store's manager, bookkeeper, custodian, and two cashiers, as well as three customers (two of them identical twin supermodels), a sales rep, a security guard, the owner of the store next door, and a convicted thief. They can follow the thinking processes of a young detective on her first case as she collects DNA evidence in an effort to identify the culprit. 

The author compares DNA identification to a high-tech fingerprint. Both can be inadvertently left behind and collected from crime scenes. The book includes profiles of past DNA rock stars, such as Gregor Mendel and Rosalind Franklin. A cartoon page or spread at the end of each section brings readers back to the crime in question. The detective outlines what she's learned. In most cases, readers can use this information to eliminate suspects. By the end, the detective — and readers — have their man — er, woman.

Books such as these provide excellent introductions to topics kids will continue to learn about throughout their student years — and likely their entire lives.