Covid has reminded us that living is a delicate balance of harmony and disharmony with our environmental partners – most recently, viruses. It has only been a couple of decades since our last major epidemic, HIV, was untreated and unpreventable. But things have changed and while Covid is on the way to becoming the equivalent of a “viral flu”, a new contender Monkeypox, is spreading from Africa to the rest of the world.
Many of the new infectious diseases are attributed to increased human travel and mobility. That sounds likely, but there is simply no evidence to back up this claim.
What we do know is that microorganisms can cause illnesses, and humans and microorganisms have a complicated, symbiotic relationship – they love us, and we love them, until they infect us with disease. We have billions in our body and on our skin at any one time. Most of them live in harmony with us. However, once an infectious agent is at large, identifying paths of transmission in our environments and minimizing them becomes a major hurdle. Most people spend around 90% or more of their time indoors. Certain environments, such as hospitals, colleges and care facilities, are well known for harbouring biological contaminants and therefore have been at the forefront of enhanced preventive strategies.
But are our homes B&Bs for a range of infectious guests that we would rather not have?
Between 30% and 50% of all structures have damp conditions that may encourage the growth and build-up of biological pollutants. This percentage is likely to be higher in warm, moist climates.
Bacteria, such as legionella, enter through hot water and air conditioning services. Fungi, such as histoplasma and aspergillus, are found in mould. Concrete building material is the least likely to retain humidity, but how many residential buildings are made of concrete these days?
Fortunately, most viruses – such as Covid and HIV — don’t last very long outside the human body. Other biological species, such as fungi, can thrive on books, wood, paint, cooking oil, and stored foods. For those of us who love our domesticated pets, cats and dogs living in the indoors have 56 and 24 different species of bacteria respectively.
Of course, not all of us will get sick from these exposures, even in our own homes. Multiple outbreaks such as we have seen with Covid and now Monkeypox, have highlighted how infectious diseases transmission differs according to economic, environmental factors and sociological factors, not just biological ones. Unfortunately, research is sorely lacking on how infectious diseases are transmitted, which microorganisms are dangerous, and how we can prevent infections in our homes. We need researchers to turn their attention to preventing disease in our work and home environments.