A woman wearing a protective face mask walks on London Bridge in London, Britain, March 3, 2020. REUTERS/Henry Nicholls

LONDON (Reuters) - The British government launched a wide-ranging public health campaign on Wednesday in a bid to slow the spread of coronavirus, a day after warnings that as many as one in five employees could be off work at the peak of the outbreak.

The United Kingdom has so far had 51 confirmed cases of the virus, and Prime Minister Boris Johnson said it was highly likely the number would rise.

Adverts informing people on how to protect themselves will appear on social media, in newspapers, on television and on billboards.

They warn that some viruses can live on surfaces for hours and that people should wash their hands more regularly and for up to 20 seconds or use hand sanitizer.

The campaign suggests people should wash their hands when they come in from work, after blowing their nose, coughing or sneezing, and before they eat or handle food.

“We all have a role to play in stopping this disease and that’s what this expanded campaign is all about – making sure the public knows exactly what they should be doing,” said health minister Matt Hancock. “Washing hands regularly is the single most important thing that an individual can do.”

The adverts suggest people should carry tissues to use when coughing or sneezing before binning them.

Britain unveiled its “battle plan” to tackle the spread of coronavirus on Tuesday. It includes possible school closures, home working and cancelling large-scale gatherings to delay the peak of the outbreak.