Hand Disinfectant and COVID-19 – a lay summary
We have known since the mid-19th Century that washing hands can save lives. That was when the Hungarian physician Ignaz Semmelweis showed that when he introduced regular handwashing in his obstetric ward, mortality from infection fell by 90% in two years. Could handwashing have the same effect on COVID-19?
- Effective handwashing should include every part of the fingers and hands, including the thumbs, the backs of hands and fingers, between the fingers, and the wrists. Liquid soap or antiseptic detergent should be used. Afterwards, the hands should be rinsed under running tap water and dried with paper towels.
- Coronaviruses have a viral envelope, which means they could be vulnerable to surface-active agents such as soap, and also to alcohol.
- In the laboratory, the effectiveness of hand sanitizing products has been measured by looking at how many of the virus are left on the skin after use. The studies have been conducted with SARS-CoV-1 – the coronavirus which was responsible for outbreaks of SARS (severe acute respiratory syndrome) between 2002 and 2004. These studies found that several hand-rub products with an alcohol content of at least 75% removed 99.99% of the virus from the hands; 70% alcohol removed more than 99.9%. It seems likely they would have a similar effect on the related virus SARS-CoV-2, which causes COVID-19.
- Real-life studies have looked at whether handwashing actually reduces person-to-person spread of respiratory viruses. Results from these support the claim that frequent handwashing halves the spread of respiratory infections.
- The highest quality trials suggest that spread of respiratory virus can be prevented by hygienic measures, such as handwashing, especially around younger children.
Taken together, the evidence supports the view that frequent and careful handwashing will reduce the chances of catching COVID-19.
Mandy Payne, 7 April 2020
This is a lay summary of a report repared for the Oxford COVID-19 Evidence Service of the Oxford Centre for Evidence Based Medicine, Nuffield Department of Primary Care Health Sciences, University of Oxford by Robin Ferner, and posted on 17th March 2020.
Disclaimer: the article has not been peer-reviewed; it should not replace individual clinical judgement and the sources cited in the original report should be checked. The views expressed in this commentary represent an interpretation by HealthWatch and do not necessarily represent those of Oxford CEBM, the NHS, the NIHR, or the Department of Health and Social Care. The views are not a substitute for professional medical advice.