Handwashing six to 10 times a day is linked to a lower risk of seasonal coronavirus, supporting public health guidance around measures for the Covid-19 outbreak, research suggests.

Regular handwashing can reduce personal risk of getting an infection, a study which has not been peer-reviewed indicates.

Moderate-frequency handwashing was associated with a 36% reduction in the risk of coronavirus infection compared to those who washed their hands zero to five times per day.

Good hand hygiene should be practised at all times regardless of whether you show symptoms or not

For higher intensity handwashing there was no significant dose-response effect, the researchers say.

Sarah Beale from University College London’s (UCL) Institute of Health Informatics, and first author on the study, said: “Given that Covid-19 appears to demonstrate similar transmission mechanisms to seasonal coronaviruses, these findings support clear public health messaging around the protective effects of handwashing during the pandemic.

“It’s important to highlight that frequency of handwashing is only one aspect of hand hygiene.

“We also know that both longer duration of handwashing and the context of handwashing e.g. upon returning home or before eating – have been associated with lower overall risk of influenza or influenza-like-illness.

“Good hand hygiene should be practised at all times regardless of whether you show symptoms or not.

“This will help protect yourself and prevent unwittingly spreading the virus to others around you.”

The research, published in Wellcome Open Research draws on data from three successive winter cohorts (2006 to 2009) of the England-wide Flu Watch study.

For the study, 1,633 participants provided baseline estimates of hand hygiene behaviour and coronavirus infections were identified from nasal swabs.

Almost 80% of participants were aged over 16.

At the start of each season, participants were asked to estimate how many times they had washed their hands the previous day.

Frequency of daily handwashing was subsequently categorised as low, zero to five times daily, moderate, six to 10 times daily, or high, more than 10 times daily.

Ellen Fragaszy, UCL Institute of Health Informatics and the London School of Hygiene and Tropical Medicine, said: “Something as simple as washing our hands regularly can help us to keep the infection rate low and reduce transmissions.”

The authors write: “This is the first empirical evidence that regular handwashing can reduce personal risk of acquiring seasonal coronavirus infection.

“These findings support clear public health messaging around the protective effects of hand washing in the context of the current Covid-19 pandemic.”

The research was funded by The Medical Research Council and Wellcome Trust.