With the daily spike in the cases of the coronavirus, wearing of masks — in addition to other preventive measures like staying at home, hand washing and keeping social distance — might help to slow down the spread of Covid-19.
On Tuesday, the World Health Organisation (WHO) revised its stand on masks, acknowledging that wearing a medical mask is one of the prevention measures that can limit the spread of certain respiratory viral diseases, including Covid-19.
The revision came after months of dithering on the issue despite mounting evidence that countries that adopted the use of masks for everyone, such as China, Japan, Thailand, South Korea and Taiwan, have slowed down the lethal itinerary of Covid-19 as compared to the United States and Europe.
They recorded fewer infections and deaths.
Even before WHO's advisory, Health Cabinet Secretary had called on Kenyans to start wearing masks outdoors to stop the spread of the disease.
Barely an hour after the post was published on the organisation’s website, scientists criticised WHO for failing to acknowledge the role that people who do not show symptoms of the disease play in the transmission of Covid-19 and how masks can stop that.
Dr Eric Topol, a physician and a member of USA’s National Academy of Medicine tweeted: “The new WHO guidance on masks is very disappointing, ignoring the asymptomatic carrier rate (25% or higher) and not advising masks for all in public.”
The US federal Centres for Disease Control and Prevention (CDC) also warns that as many as 25 per cent of people infected with the new coronavirus may not show symptoms. The CDC has broadened its guidelines on who should wear masks.
A recent review in the medical journal Lancet noted: “As evidence suggests Covid-19 could be transmitted before symptom onset, community transmission might be reduced if everyone, including people who have been infected but are asymptomatic and contagious, wear face masks.”
The prophylactic use of masks also worked in the favour of the Asian countries in the 2003 Sars virus outbreak.
Dr Patrick Oyaro, an epidemiologist and a public health expert, explained how face masks prevent diseases.
He told the Nation that masks are “a physical barrier” which catch tiny organisms (microbes) that the sick person may expel to the environment. Masks also protect the healthy people from inhaling the germs in the environment.
The N95 masks and respirators have become popular. They draw their name from their ability to filter out 95 per cent of nearly all of bacteria, viruses, fungi and other microbes even in their tiniest form, as tiny as 0.3 microns wide.
More evidence is also coming that Covid-19 could be airborne, and that the mere act of talking and breathing releases these pathogenic germs to the air which one can breathe and get infected. Dr Jeremiah Chakaya told the Nation: “Any time someone who has a disease that has affected the lungs, such as Covid-19, there is a possibility that when they speak, sneeze or cough, they will release large and small droplets in the air.”
Another researcher, Dr Josh Santarpia who studies biological aerosols at the University of Nebraska Medical Center in the United States, found out that when a person stands by the bed of a patient, it does not matter whether the patient is speaking or not. The particles the patient emits as they breathe will be inhaled in by someone that is a metre and a half away from them, at the foot of their bed.
N95 masks are available in pharmacies for at least Sh200.
With costs a challenge, the CDC is also advising that people can sew their own masks because all one needs is a simple barrier to reduce the spread of coronavirus by blocking outgoing germs from coughs or sneezes of an infected person as well as well as protect people from incoming germs.
What is the best fabric for this? Speaking to the New York Times, Dr Yang Wang, who is an assistant professor of environmental engineering at Missouri University of Science and Technology, said the fabrics for homemade face masks need to be “efficient for removing particles, but you also need to breathe”.
Dr Wang’s research reported that four layers offered protection than two layers.
There is a proper way to dispose of the masks. Kenyatta National Hospital’s Elly Nyaim warned the wearer not to touch the outer front part of the masks.
Dr Nyaim said: “If it had trapped any pathogen there, then you touch it and then touch your face or clothes, you contaminate yourself.”