The Nigeria Centre for Disease Control, on Saturday, warned Nigerians that the use of face shields without an additional layer of face masks is not effective in Coronavirus (COVID-19) prevention.

The agency in a public advisory said while the use of face masks has been advised by the World Health Organisation following increasing transmission of COVID-19, many people have resulted in using face shields in its stead.

WHO had earlier provided a recommendation for the wearing of face masks by the general public especially in places where there is ongoing spread of the virus.

The agency said the usage of the face mask alone is not enough to curtail transmission of the virus. Other means such as physical distancing and frequent handwashing have been advocated to keep people safe from contracting the virus.

Advisory

There has been an increasing trend in the use of the face shield in place of the face masks, the agency said.

The NCDC said “following evolving evidence on the transmission of COVID-19, it has published a public health advisory on the appropriate use of face masks and face shields”.

The agency said the advisory became necessary “following increasing availability and usage of face shields, in the place of face masks, which is especially important where there is ongoing widespread transmission of COVID-19 and physical distancing is difficult.”

The use of face masks was recommended by WHO in places where the spread of the virus is ongoing and physical distancing is difficult to observe – such as markets, public transport and crowded places.

In Nigeria, the Presidential Task Force on COVID-19, on April 27, had mandated the use of face masks or covering in public spaces.

As of Friday, Nigeria has reported 23, 298 confirmed cases of COVID-19, with 554 deaths recorded in 35 states and the Federal Capital Territory.

‘Face shields not enough’

While discouraging the use of only face shields, NCDC said there is currently no guidance provided by WHO or other relevant public health authorities that recommends the use of face shields in non-healthcare settings to prevent COVID-19.

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It said given the limited evidence on the effectiveness of face shields in protecting people from COVID-19, they should not be used alone.

Face shields are generally used in health care settings by medical professionals to provide barrier protection to the facial area, including the eyes, nose and lips.

Even in healthcare settings, face shields are not meant to function as primary respiratory protection to prevent infection. Face shields are used in combination with surgical masks or N95 masks by health workers for maximum protection during invasive procedures such as intubation.

The Nigerian public health agency said there are no published studies on the effectiveness of face shields against COVID-19 in non-healthcare settings.

NCDC also said it is important to remember that currently, no single intervention even when properly used, provides complete protection from COVID-19 infections.

“Therefore, the use of face masks or face shields with face masks should be combined with other public health and social measures as announced by the federal/states ministry of health and NCDC.

“This includes maintaining distance of two metres between you and the next person, frequent hand washing with soap and running water or use an alcohol-based hand sanitizer and avoid public gatherings,” it stated.

NCDC said it will continue to update its recommendations as knowledge about COVID-19 evolves.