How Effective is Hand Washing in Killing Germs: The Case of COVID-19

Hand washing is a simple yet powerful tool to reduce the spread of germs, including the highly infectious SARS-CoV-2 (the virus responsible for the COVID-19 pandemic). It is important to understand how hand washing affects the number of germs and how it specifically impacts viruses such as the one causing the current global health crisis.

Introduction to Germs and Hand Hygiene

Hand washing is not just about killing germs; it is also about rinsing away them, which is equally crucial. When germs become trapped in dirt or other residues on the hands, the use of soap helps to dissolve the dirt and facilitates rinsing. This process aids in removing the germs effectively from the hands. It is important to note that while hand washing does kill a large number of germs, the primary goal is to rinse away the germs rather than relying solely on the killing action.

When it comes to the specific case of the coronavirus, hand washing is particularly effective. The COVID-19 virus is found to be a lipid virus, which means it has a lipid (fatty) membrane enveloping its protein structure. When this lipid membrane is exposed to soap and water, it dissolves. This dissolution process disrupts the structural integrity of the virus, causing the coronavirus to leak out its content and become inactive. As a result, the virus loses its ability to replicate and infect cells, effectively destroying its viability.

Quantifying the Germ Kill Rate

One might wonder, ‘what percentage of germs does hand washing kill?’ This question is often challenging because the number of germs can vary significantly depending on the initial contamination and the specific circumstances of the hand washing routine. However, it is well-established that hand washing can reduce the number of bacteria and viruses on the hands by 80% to 99%. For example, studies have shown that hand washing can eliminate up to 99.99% of common bacteria and up to 90% of viruses on the hands after a thorough washing with soap and water for at least 20 seconds.

Understanding the Impact of Soap and Water

Soap is effective in dissolving the protective lipid layer surrounding the coronavirus. This lipid layer plays a crucial role in protecting the virus from external environmental factors. By dissolving this layer, soap helps access the inner structure of the virus, which is sensitive to moisture and other environmental conditions. Once this lipid layer is disrupted, the virus loses its protective casing and becomes inactive. This process, coupled with the rinsing action provided by water, ensures that the germs are effectively removed from the hands.

Conclusion

Hand washing plays a vital role in reducing the spread of germs, including viruses like the SARS-CoV-2. While it is true that hand washing does not kill 100% of germs every time, its effectiveness comes from both the killing action and the rinsing away of germs. For the COVID-19 virus, the use of soap and water is particularly effective in destroying its lipid membrane, rendering it inactive. In summary, hand washing is a reliable and effective method for reducing the number of germs and preventing the spread of infectious diseases.

Keywords: hand washing, germ killing, COVID-19