Protective facial masks worn by many medical practitioners not safe, study finds
10th December 2020
KN95 masks distributed in SA fail the stipulated safety thresholds – Study finds
24th December 2020
Sunday Times – 20 December 2020 – 00:57 By Paul Ash, Naledi Shange, Tanya Farber and Nonkululeko Njilo
Image: 123rf/boumenjapet
Concern over new variant of Covid-19 as professional masks fail efficacy tests
As SA rides the tsunami of a second surge of Covid-19 and a new ultra-infectious variant, authorities have moved to tighten the licensing and regulation of face masks – after a study found that some KN95 masks distributed to health-care workers were not effective.
The South African Health Products Regulatory Authority (Sahpra) says the Special Investigating Unit (SIU) is probing six charges against companies supplying non-compliant masks.
This comes as the presence of a new variant of the virus – spreading fast and “making young and previously healthy people severely ill” – was announced by health minister Zweli Mkhize this week.
Scientists have raised concerns that the variant will put additional strain on hospitals “in the next weeks or even next few days”, leading to possible higher mortality rates.
Adding to the government’s concerns is the festive holiday season, with many people travelling across the country to visit family and friends, and increasing the risk of infection. This is despite the government closing beaches in the Eastern Cape, the Garden Route and on busy public holidays in KwaZulu-Natal.
Professor Tulio de Oliveira, head of the KwaZulu-Natal Research Innovation and Sequencing Platform (Krisp), which has conducted genomic sequencing on Covid-19, told the Sunday Times that “people should be very concerned as there is clear evidence that this lineage may be far more transmissible”.
“Our hospitals will get close to being overwhelmed in the next weeks or even next few days. Once our hospitals run out of beds, it will be very difficult to provide space in ICU and provide oxygen and ventilators. Then the excess deaths will be much higher this time around.”
It will be weeks or even months before genomic science proves whether this variant is either more or less lethal, but the sheer numbers of infections are already resulting in high mortality.
“Nelson Mandela Bay and Buffalo City are already seeing higher excess deaths. Mortality is increasing much faster than we expected,” said De Oliveira.
Wits University vaccinology professor Shabir Madhi, however, disagrees that the new variant is more transmissible, referring to an article in reputable science journal Nature showing that “there is no evidence at all that any new variant is more infectious than another”.
“It is less to do with the variant and more to do with people not adhering to non-pharmaceutical interventions,” he said.
The only explanation for more young people being affected this time around is “that they’re even less likely to stick to the non-pharmaceutical [interventions] and we’ve already seen this with clubs, bars and restaurants”, he said.
Professor Ian Sanne, like Madhi a member of the ministerial advisory committee, is also head and founder of Right to Care, a health organisation that responds to public health emergencies. He said he is “worried” because the variant that has become dominant has “increased binding affinity and higher viral loads”.
“Whether that goes with a less severe disease, we don’t know … but the case rates are on a very steep curve in the main provinces and the private sector is now at maximum capacity with full ICUs and high care, and even general wards are having to turn away elective procedures to accommodate new cases.”
He said public hospitals will reach capacity, and that Right to Care has recommended that surge capacity is increased within existing hospitals rather than by opening field hospitals as the latter require additional logistics, management and staffing.
“Our ICU colleagues are surprised by the number of admissions in the age group 15 to 25 and severity of presentations and their need for ventilation. We are no longer convinced that young people have any special protective mechanism or physiology. They are also prone to severe infections.”
However, despite calls by the government for people to stay home, the ANC is going forward with its 109th birthday celebration events in early January.
The party will host its supporters in various celebrations, with the main event in Limpopo, where President Cyril Ramaphosa will deliver the January 8 statement. The party has vowed to keep attendance numbers to a minimum, with only 100 at the event in Limpopo.
Meanwhile, the coalition tasked with testing Covid-19 personal protective equipment at the start of the pandemic said that only “a fraction” of the PPE that had arrived in SA then was tested. The coalition was made up of the South African Bureau of Standards (SABS), Business for SA and the National Regulator for Compulsory Specifications (NRCS).
Business for SA health working group chair Stavros Nicolai said the study, conducted by researchers at the University of Cape Town, had revealed “a microcosm of what’s actually gone on out there”.
“From late February and most of March, global supply chains were highly constrained,” Nicolai said. “As Chinese capacity recovered in May, a deluge of product began arriving in SA.”
He said none of the suppliers whose masks were tested in the UCT study had been passed by Business for SA.
Sahpra spokesperson Yuven Gounden told the Sunday Times this week: “Where there is strong evidence that the non-compliance was approved by the company knowingly, criminal charges will be laid.
“Sahpra has laid six charges against suppliers so far. These cases are under the jurisdiction of the SIU and therefore the names cannot be divulged.”
National health department spokesperson Popo Maja said compromising health-care workers’ safety was “not intentional”.
He said that though the study had used masks mainly from facilities in the public and private sectors in the Western Cape, “the researchers have now extended the opportunity to test masks in other areas, which we are working with them on”.
“At this stage we are not aware of unsafe masks in other provinces … the Western Cape department of health had already withdrawn the poor-quality masks when the researchers shared the results with them.”
The government, however, will be toughening its procurement methods to ensure they receive quality products in future.
He stressed that the national department did not purchase KN95 masks. “These masks are purchased by provincial health departments and in some cases directly by the health facility. Generally, KN95 must be evaluated and registered with Sahpra for medical use.”
The UCT study, published in the South African Medical Journal, tested 12 brands of KN95 masks that have been distributed to health-care facilities for frontline workers. It found that not one offered the same protection as the “gold standard” N95 face mask.
One of the authors of the UCT study, Keertan Dheda, who is the head of pulmonology at UCT’s medical school, said the KN95 standard was supposed to match the US N95 and the European FFP2 standard for filtration of particles and “leakage” from the side of the mask. In September, the US’s largest nonprofit patient safety organisation, ECRI, found that nearly 70% of KN95 masks did not meet US standards for filtration efficiency.
The UCT study found that only half of the masks tested met the filtration standard, but none of them passed the test for stopping inward leakage.
Part of the problem is that KN95 masks use ear-loops rather than head-straps, said professor Barry Schoub, who sits on the ministerial advisory committee on vaccines.
Nursing union Denosa slammed the health department for failing to take responsibility for the masks, saying it will take legal action if all KN95 masks are not immediately withdrawn.
Making sure your mask fits
Want to test your KN95 mask? All you need is a home aroma diffuser, widely available from about R200, and a large freezer bag.
Researchers from Cambridge University in the UK used the items to develop an inexpensive and reliable method for assessing the fit of masks that are designed to seal, such as N95, KN95, FFP2 and FFP3 models.
They said commercial testing equipment is not only expensive but has been in short supply during Covid-19, forcing many health-care institutions to abandon regular fit-testing for staff.
The new method uses cheaper versions of the apparatus in commercial kits: a testing solution, a diffuser to atomise it and a hood.
In a typical fit test, a user places the hood over their head while wearing a mask, and the solution – usually sweet or bitter – is aerosolised into the enclosure as a fine mist.
The fit of the mask is assessed by how well the user can taste the solution while nodding their head or speaking.
In the replacement device, the combination of an aroma diffuser and a freezer bag gives results comparable to commercial solutions.
“Our homemade replacement requires further testing for safety and efficacy: in particular, the use of a plastic bag to concentrate the vapour remains a safety concern,” said Eugenia O’Kelly of Cambridge University’s engineering department, first author of a study published in the journal Disaster Medicine & Public Health Preparedness.
“We were happy to find an inexpensive set-up to assess the fit of masks. Given the importance of masks in slowing the spread of Covid-19 and other airborne viruses, it’s essential that they fit properly, especially in health-care settings.”
– Dave Chambers
