While near-total lockdowns have been imposed in Italy, Spain, and now France, the World Health Organization's advice has remained unchanged since the start of the global outbreak: wash your hands, don't touch your face, and keep your distance.

The WHO says it is advisable to wear a protective mask in public if you suspect you are infected or someone you are caring for is, in which case the advice is to stay home whenever possible.

"There are limits to how a mask can protect you from being infected and we've said the most important thing everyone can do is wash your hands, keep your hands away from your face, observe very precise hygiene," said WHO's emergencies director Mike Ryan.

The advice is all the more urgent given the WHO's estimate that health workers worldwide will need at least 89 million masks every month to treat COVID-19 cases.

There are already shortages of masks for medical professionals around the world, a problem that could get worse as the pandemic drags on.

But the message about masks hasn't reached everyone.

"I'm surprised to see through the window in my ministry lots of people in the street wearing masks when that doesn't correspond to our recommendations," French health minister Olivier Veran said Monday.

Mariam, 35, told AFP that she was wearing a mask because she has an elderly mother.

"Just in case," said Mariam, who was also sporting latex gloves.

Mariam, who didn't want to give her last name, she said she got her mask from "a friend's mother who works in a hospital."

Contaminated masks

As well as hoovering up stocks sorely needed by medical professionals, experts say masks can give people who wear them a false sense of security.

For example, many people who wear them don't follow the official advice of washing their hands thoroughly first, ensuring it's air tight and not to touch it once it's on.

"People are always readjusting their masks and that has the potential to contaminate them," said France's head of health, Jerome Salomon.

"If someone has come across the virus, it's surely going to be on the mask."

Gloves, similarly, don't greatly heighten protection and could even end up making you sick.

"If people cannot stop touching their face, gloves will not serve a purpose," Amesh Adalja, from Johns Hopkins Center for Health Security, told AFP.

One 2015 study in the American Journal of Infection Control found that people touch their face on average 20 times an hour.

The novel coronavirus is transmitted via skin contact, transferring infected globules of mucus via the ears, eyes or nose.

"Gloves are not a substitute for washing your hands," said Adalja, adding that surgical gloves should only be used in a medical setting.

Plus, said Veran: "If you're wearing gloves you're not washing your hands."

For one Paris resident, Oriane, 32, this is not a problem.

"I wash my gloves," she said, gesturing to her bright blue surgical mitts.