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Aug 11, 2021

Airborne infections in history and today – an interview with Dr. Jon Edman Wallér

More and more people are aware on how the air affects us and our surroundings, and due to the pandemic, the quality of the air is in focus. Many questions are raised, but surprisingly few answers are available. This article explains the lack of knowledge among professionals and provides an in-depth understanding of how clinical learnings evolve through generations.

It has been known for a long time that the right humidity and the right indoor climate have a positive effect on us, both in terms of health but also in terms of energy level, performance, and well-being. In addition, the environment must be safe. Following the recent learnings on infection prevention, and the discussion about airborne transmissions and droplet infections, more and more people are considering this as a new and important subject. But have we not known this for centuries?

Dr. Jon Edman Wallér, Resident physician in Clinical microbiology and infection control, wrote an article* about how diseases are transmitted through the air, and how discussions have taken place over the past 2000 years. This is something that we at Avidicare noticed and wanted to know more about.

After giving an inspirational lecture on the Master’s program in Infection Protection and Control at Gothenburg University, Jon immersed further into airborne infection and how it has been handled historically. The result was a different approach to a topic now discussed by all, and one that gave deeper insights also into how clinical learnings evolve through generations. It became an article published in Läkartidningen (Swedish Medical Association monthly paper) that has been widely read.

Dr. Jon Edman Wallér

In his article, Jon mentions that people have historically believed in the idea of the Miasma – diseases arise through bad air from rotting carcasses and stagnant water, which in turn disrupts the balance of body fluids. It was not until the middle of the 19th century that this ancient idea gained competition when mankind began to understand the connection between microorganisms (such as bacteria) and diseases. 

It became obvious that these microorganisms that were found on clothes, instruments and surfaces had to be removed. Unfortunately, an unintended consequence became that airborne infection was almost rejected, because it was too close to the old idea of the Miasma. And moreover, if the air was a major pathway of infections, it may overshadow the importance of the hands-on methods that had to be introduced to fight contact infection. 

Jon recognizes the way of thinking, when you talk about airborne infection it leads to feelings of discomfort and that it is difficult to protect yourself against. An airborne infection will be difficult to handle, and with the higher standard of proof that an infection is airborne, there will be different standards depending on the route of infection. 

As a basic assumption, you see an infection as a contact infection, and to re-classify it as an airborne infection calls for strong evidence. Historically, it has been hard to classify both tuberculosis and measles as airborne infections, which by now have been shown to be so beyond any reasonable doubt.

We ask Jon how he is reasoning about airborne infection, and he thinks that the concept itself is a bit difficult. “You have to define the boundaries so that it is clear what you are talking about. The limit between an airborne infection and a droplet infection is vague, and not completely clear. It must also be taken into account that all airborne infections are not only transmitted from person to person but can be transmitted via water pipes and mold spores. Surgical infections thru the air are also an indirect infection, from skin to air to wounds for example. At the same time, the droplets in the air are still droplets.”

Speaking of surgeries; When it comes to fomites and indirect contact infection in the operating room, Jon thinks that OR teams have excellent know-how, that sterility is important and that the operating staff has control over the degrees of cleanliness. 

However, outside the operating room there are often lower levels of hygiene, which becomes a concern when relocating various minor orthopedic, eye and skin procedures to reception rooms or non-operating rooms. When you also have energy saving requirements that lower the airflow of the ventilation, the risk of infections increases.

With an increasing number of infections, the use of antibiotics also increases. Jon says that antibiotic resistance is a part of his everyday life, both as a doctor and as an infection preventionist. “We live on borrowed time if we do not come up with a new radical way to treat infections.”

The argument that antibiotics and antibiotic prophylaxis prevent or cure any infections is not something that is applicable on implant surgery, where an infection is not something that is easily remedied with an antibiotic regimen. If you look at infection prevention in a larger perspective, you should prioritize to slow down the development of resistance through good hygienic routines, thus avoiding any contamination from the beginning. In the short-term perspective however, all antibiotic treatments that cure are a benefit. 

We should also note that the bacteria that cause infection are a very small part of the entire bacterial population. Still, they are the bacteria that you worry about the most. Persons admitted to a hospital, for example long-term treatment or ICU, have their original bacterial flora partly replaced by bacteria that are coming from the hospital environment, which unfortunately have a broader resistance. Major problems can arise with far too generous use of antibiotics in the hospital as well as from inadequate hygiene routines. Then the resistant strains thrive and colonize in patients but also in staff. It is not only at the moment of surgery that one should have the right preventive measures, but all routines within the care are important.

“We live on borrowed time if we do not come up with a new radical way to treat infections.”

— Dr. Jon Edman Wallér

When building, or renovating, a hospital, there are always different interests and cost aspects to take into account. What is clear is that there is a direct relationship between bacteria in the air and the risk of infections. Charnley **, and Lidwell *** have early on shown that this is the case, but re-doing those studies is not feasible due to the large number of patients needed. There is also the ethical question of who should be operated on in dirty air and who should get the ultra-clean air? Jon says: “From my experience, it seems reasonable to promote high air purity”.

In recent years, the Infection Prevention and Control Teams have been involved early in the construction processes, in order to provide its input to good care from a hygiene perspective. When old premises are rebuilt and replaced, it is important to build modern and innovative technical solutions that will last for care for many decades. Projects need to be staffed with persons who have a holistic approach to advocate for hygiene at all levels, and who can review current routines and how they can be improved.

Following the pandemic and looking ahead, Jon believes that infection prevention and control will be valued higher and given more resources, and that everybody realizes the importance of hygiene in a modern way. In annual reviews of hygiene routines, some departments have the right conditions, while other departments lack routines. These differences became crystal clear during the pandemic where successful departments had well-established routines and could quickly adapt and manage the adjustment and requirements due to the pandemic. It became an eye opener for everyone to have such routines in place, and that areas of care and reserve stocks must be expanded. You need some margins to be able to provide good care even under extreme pressure.

With today’s hygiene routines, there are different measures in case of droplet infection or in case of airborne infection. As a doctor, you are forced to decide on one or the other, based on different criteria. Scientifically, Jon believes that we need to understand that it is a sliding scale where both must be addressed. There will be a continued debate and questions about what risks that are acceptable when faced with both a droplet and airborne aerosol-based infection. Still, it remains clear that good air quality has a preventive impact on infection risks, regardless of whether it is classified as airborne or as a droplet infection. 

We thank Dr. Jon Edman Wallér, for an interesting and well written article, and for generously answering our questions.  

* Läkartidningen

** Charnley

*** Lidwell