Expert urges caution on healthcare worker cloth mask use

Dwindling supplies of respirators and disposable surgical face masks during the coronavirus (COVID-19) pandemic has led some healthcare workers to seek alternatives such as cloth masks. Yet Professor Raina MacIntyre, a biosecurity expert from the University of New South Wales’ Kirby Institute, has urged caution. Workers should ensure they understand the current evidence and make an informed choice before choosing to work with inadequate personal protective equipment (PPE), while the sector should use evidence and provide clear guidance to workers, especially when alternatives are selected in situations where appropriate PPE are stretched or unavailable, Professor MacIntyre said.

Advice to industry

“These are desperate times,” Professor MacIntyre said, “and alternatives, and evidence to support them, are being sought.” But such alternatives need careful consideration, Professor MacIntyre has warned, making reference to her 2015 study, in which surgical masks are shown to be superior to cloth masks in protecting against infection. The study also found that cloth mask wearers had higher rates of infection than the standard practice control group of health workers, many of whom wore no mask. “The key point [the study] demonstrated is that cloth masks do not protect as well as surgical masks and may increase your risk if not washed and replaced daily,” Professor MacIntyre said.

“It is critical for hospitals and governments to plan and stockpile proper disposable products to protect healthcare workers in a crisis such as the one we are currently experiencing,” Professor MacIntyre said, also urging the medical research community and other industries to come together to support frontline healthcare workers at this time. “Many of us, including medical researchers, industry and other workplaces have PPE stocks that healthcare workers dealing with COVID-19 are in desperate need of,” Professor MacIntyre said. “We need to be nimble and pool all our available resources. Let’s donate what we have to frontline clinicians.”

Advice to workers

“I suggest that cloth masks only be used in the general community, and people should have at least two and cycle them, so that each one can be washed and dried daily after use,” Professor MacIntyre said. This is in line with current guidance from the Centers for Disease Control and Prevention, which describes surgical masks or N-95 respirators as “critical supplies that must continue to be reserved for healthcare workers and other medical first responders”. Any physical barrier over the mouth and nose should provide some protection against self-contamination with hands, Professor MacIntyre said, but will not protect as well as a respirator or surgical face mask.

Cloth masks performed poorly in Professor MacIntyre’s study as they were found to have poor filtration, and became damp and contaminated, creating an environment for infection. Correct use of cloth face masks involves daily washing and sterilisation; alternative options include re-use or extended use of disposable masks. Research is underway about sterilising disposable masks, but Professor MacIntyre cautions that this is also risky — a recent study revealing that SARS-CoV-2 was found on the outer surface of a mask seven days after contamination.

Professor MacIntyre suggested that workers could procure their own PPE if their employer is unable to provide it. A variety of re-usable masks, including industrial respirators, may be available online, which can be cleaned according to the manufacturer’s instructions. “It’s important to look for products that have certified respirator status, which can be identified on the packaging, but waiting times may be long and even these supplies are short,” Professor MacIntyre said.

Action for the future

Professor MacIntyre called for the health and safety of health workers to be prioritised — not only in the context of their critical role during COVID-19, but in society at large as well, now and into the future. “If a large proportion of doctors and nurses become sick, or even die, the ability to respond to the pandemic and to treat other serious illness will be compromised,” Professor MacIntyre said. “Moving forward, we really need to ensure that stockpiling of PPE is far better than it has been leading up to this crisis.”

The COVID-19 situation in Australia is changing rapidly. For the latest information visit www.australia.gov.au.

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