Following evolving evidence on the transmission of COVID-19, the World Health Organization (WHO) provided recommendations for the wearing of face masks by the general public. This is especially important where there is ongoing widespread transmission and physical distancing is difficult, such as in public transport, markets, and confined or crowded environments. In Nigeria, the Presidential Task Force on COVID-19 mandated the use of face masks or coverings in public spaces, on the 27th of April 2020.
The Nigeria Centre for Disease Control (NCDC) published advisories on the use of face masks and guidance on making cloth masks.
The use of face masks for COVID-19 prevention is important, as recent studies indicate that a significant proportion of people who have COVID-19 do not show symptoms (asymptomatic), and the virus can spread before these people know that they are sick (presymptomatic). SARS-CoV-2 which causes the coronavirus disease, can spread from person-to-person through respiratory droplets, often through speaking, coughing or sneezing. There is evidence that the correct use of face masks reduces the risk of COVID19 infection.
An increasing number of people in Nigeria are now using face shields, in the place of face masks, as they become more widely available. 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 mask or N95 mask by health workers for maximum protection during invasive procedures such as intubation.
There are no published studies on the effectiveness of face shields against COVID-19 in non-healthcare settings.
The NCDC offers the following guidance to Nigerians on the appropriate use of face masks and face shields:
1. Face masks are very important in helping to limit the spread of COVID-19, especially in situations where physical distancing may be difficult, such as on public transportation, markets and in areas where there is a significant amount of community transmission.
2. For effective protection, face shields are used in combination with an appropriate face mask in healthcare settings.
3. There is currently limited to no evidence on the effectiveness of face shields to prevent COVID-19 when used alone by the general public in nonhealthcare settings.
4. There is currently no guidance provided by the WHO or other relevant public health authority that recommends the use of face shields in non-healthcare settings to prevent COVID-19.
Given the limited evidence on the effectiveness of face shields in protecting people from COVID-19 infection in community settings, and the absence of recommendations on their use, by the WHO and other public health authorities, face shields alone should not be used in preventing the spread of the COVID-19 infection. When used, it should be done in combination with an appropriate face mask.
It is important to remember that currently, no single intervention even when properly used, provides complete protection from COVID-19 infection. 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/State Ministries of Health and the Nigeria Centre for Disease Control. This includes maintaining a distance of two metres between you and the next person, frequent handwashing with soap and running water or use of an alcohol-based hand sanitizer and avoiding public gatherings.
The NCDC will continue to update its recommendations as knowledge about COVID-19 evolves.
About the NCDC
The Nigeria Centre for Disease Control is the country’s national public health institute, with the mandate to lead the preparedness, detection and response to infectious disease outbreaks and public health emergencies. The Bill for an Act to establish NCDC was signed into law in November 2018, by President Muhammadu Buhari. The mission for the NCDC (2017-2021) is ‘To protect the health of Nigerians through evidence-based prevention, integrated disease surveillance and response activities, using a One Health approach, guided by research and led by a skilled workforce’.
