Why we are working up a lather over hand washing.

Since the global outbreak of the Corona Virus pandemic, washing your hands has been a core focus for the prevention of transmission and infection by the virus. As we unknowingly touch our face hundreds of times a day, we allow viruses and bacteria direct access to our infection pathways. Why is hand washing so vitally important for killing the virus? How does it prevent you from picking it up and becoming infected or from a person spreading the virus when they unknowingly have it?

The History of Hand Washing

While hand washing has been drilled into us over the past few months in light of the Corona Virus outbreak, it has been a central point of health, hygiene maintenance and social behaviour for many years. Hand washing dates back thousands of years, traditionally for ceremonial and religious purposes.

However, the discovery of the direct link between hand washing with soap and infection was only made in 1846 by Hungarian doctor, Ignaz Semmelweis.

The doctor had observed different death rates of mothers in two maternity wards, and considered this due to doctors in one maternity ward performing autopsies then transporting infectious bacteria from the dead to the mothers. The doctor implemented hand washing practices in this ward and saw the death rate fall drastically.

Years later in Italy, Florence Nightingale also implemented hand washing practices in an attempt to combat infections in the war hospital in which she worked. This initiative also achieved a clear reduction in infection rates. Upon returning to the United Kingdom, Nightingale promoted hand washing in hospitals and in homes.

However, despite the foundational work of Semmelweis and Nightingale, hand washing was not widely accepted and commonly implemented for another 40 years, by which time understanding of bacteria had developed and cholera, tuberculosis, diphtheria and typhoid had been identified. By the 1890s, hand washing was required by all doctors and was recommended as common practice for people generally. People understood that disease was passed on by touch, and widespread health campaigns were put in place to make hand washing common practice.

Today, hand washing with soap is universally recognised as an easy, cheap and effective way of preventing the spread of disease.

Why is soap so important and how does soap work?

Why is it that simply washing your hands with soap is so effective at preventing infection? How does soap kill viruses and bacteria?

Now we are going to get into a bit of science. Soap is made up of pin-shaped molecules with a head which attracts water (hydrophilic) and a tail that repels water (hydrophobic), but that attracts oils and fats. Many viruses have a fatty outer layer, or membrane, which are hydrophobic. When you wash your hands, the tail ends of the soap molecules try to repel or evade the water, and are attracted to the fatty membrane of bacteria and viruses that might be on your hands. In doing so, the hydrophobic tails of the soap molecules incorporate themselves into the fatty membrane of the bacteria or virus and break them apart. This disrupts the functionality of the bacteria or virus and kills it.

How you should wash your hands.

As we touch the world around us and our own faces constantly, for hand washing to be effective we need to wash our hands frequently and thoroughly with soap. Use a generous amount of soap, scrub your palms and the back of your hands, rub between your fingers and around your thumbs, and scratch with your nails. Rinse your hands thoroughly and dry with a clean towel. Posters and visual reminders can also encourage people to wash their hands when they might be tempted to skip it. Where you don’t have access to soap and water, which works to both kill and wash the virus away, hand sanitiser that is at least 60% alcohol will also kill bacteria and viruses and help to prevent their spread.