Not touching face may help cut flu risk

Monday December 3 2012

“Want to avoid flu? Stop touching your face!”, reports the Daily Mail. The paper says that researchers have “found that we ‘inoculate’ ourselves with bacteria and viruses by touching our mouths and noses with our hands after brushing contaminated surfaces”. (The paper is using ‘inoculate’ to refer to catching, or becoming infected by, a bacteria or virus).

The study in question is reported briefly in a letter to a journal. It is already known that the viruses which cause colds and flu can live for hours on surfaces, and you can become infected by touching these contaminated surfaces and then your nose or mouth, and the study did not investigate this directly.

Instead it looked at how frequently randomly selected people in public places in Brazil and the US might potentially risk infection. The researchers found that they touched surfaces in these public spaces about 3.3 times each hour, and their mouth or nose about 3.6 times each hour. The researchers say that people are not likely to be able to wash their hands this frequently when they are out in public spaces. They suggest that this may mean that during outbreaks, additional public health messages are needed to inform people of the risk of touching contaminated public surfaces and then touching their faces.

The study does not challenge the fact that handwashing is a simple, effective way to reduce your risk of being infected with bacteria and viruses that can be transmitted by hand contact with contaminated surfaces, including the winter vomiting virus.

If you already have a cold, flu, or winter vomiting bug – please remember to wash your hands after touching potentially infected materials such as tissues to help prevent it spreading.

Where did the story come from?

The study was carried out by researchers from the US National Institutes of Health (NIH) and other institutions in the USA and Brazil. Two of the authors were funded by the NIH.

The study was published as a letter in the medical journal, Clinical Infectious Diseases.

Although this is a peer-reviewed journal, it is not clear whether letters are peer reviewed. Minimal details of the study were presented in the letter.

The Daily Mail suggested that the researchers had “found that we ‘inoculate’ ourselves with bacteria and viruses by touching our mouths and noses with our hands after brushing contaminated surfaces”. The study did not actually directly assess transmission of bacteria and viruses, but assessed opportunities for transmission arising from touching surfaces in public spaces and then the faces.

The Mail quotes from what the lead researcher told the MyHealthNewsDaily website two days previously.

However, the Mail usefully includes reassurance from the author of the study that, “while it [is] good to boost awareness, there [is] no need to be in a constant state of alert because the immune system offers good protection against disease”.

What kind of research was this?

This was a cross-sectional study looking at how often people touch their faces and mouths/noses. The researchers say that during pandemics and other public health emergencies, such as the swine flu (H1N1) pandemic in 2009, educating the public on how to avoid contamination is crucial for reducing the spread of infection.

They say that recommendations for frequent hand washing during the 2009 flu pandemic were based on the assumption that people can catch the virus by touching contaminated surfaces and then touching their mouth, nose or eyes.

The researchers wanted to see how frequently people put themselves at risk of transmission of viruses in this way in public spaces.

What did the research involve?

The researchers randomly selected 249 individuals in public places in Florianopolis in Brazil, and on the subway in Washington DC over a 66-hour period.

They observed the selected individuals to see how often they touched surfaces in these public spaces and also their mouth or nose.

No further details on the methods were provided in the letter.

What were the basic results?

The researchers found that people touched surfaces in these public spaces about 3.3 times each hour, and their mouth or nose about 3.6 times each hour.

How did the researchers interpret the results?

The researchers concluded that opportunities for hands to become contaminated in public spaces were frequent, and hand washing this frequently would not be feasible.

They suggested that there should be a shift in the focus of recommendations issued during pandemics and public health emergencies focusing on the following points:

  • getting people to better understand how they can pick up the viruses from touching common surfaces and then touching their faces
  • getting people to avoid touching their faces until after washing their hands
  • if they are infected, to avoid touching common surfaces so other people do not become contaminated


This brief report suggests that when people are in public spaces, there are frequent opportunities for their hands to be contaminated with flu and to spread this and other respiratory viruses.

Contamination can occur through contact with surfaces touched by infected people, and then transferred to their mouth or nose.

The authors’ study was only reported briefly in the journal, and it is not clear whether the people being observed knew they were being observed and the purpose of the study, which could have changed their behaviour.

The authors also did not test whether people’s hands had come into contact with flu viruses on the public surfaces, though their study does suggest that there is opportunity for them to do so.

Also, the study was carried out in Brazil and the US, and assessing people in different countries could have produced different results.

It is important to note that this study does not suggest that there is no point in washing your hands. This simple measure is known to be effective in reducing the transmission of bacteria and viruses.

The study does suggest that there are many opportunities for infection with viruses such as the influenza virus by making contact with surfaces in public areas, and then touching our faces, transferring the viruses to our nose and mouth.

Being aware of this possibility may help people to reduce their infection risk by avoiding touching their faces before washing their hands when out and about.

Analysis by Bazian
Edited by NHS Choices