The COVID-19 pandemic has focused the consciousness of the nation on disease transmission in ways no other virus has before in our lifetimes. To mitigate the spread, many of us worked from home, kept our kids home from school, and dined outside. In some cases, we are still wearing masks and social distancing even as the world begins a gradual return to normalcy. Last month, the U.S. marked 750,000 COVID-19 deaths. It's a grim milestone made even more tragic by the knowledge that many of these deaths were entirely preventable.
Against this backdrop, new science around disease transmission presents an opportunity to refocus our efforts on protecting people in indoor spaces from diseases of all kinds. While the COVID-19 tragedy has unfolded daily in newspapers and on television, other viruses and bacteria have ravaged our lives in less visible ways. The CDC estimates that the flu has resulted in 9 to 41 million illnesses and 12,000 to 52,000 deaths annually between 2010 and 2020. And hospitals -- institutions whose sole purpose is to heal -- sometimes make us sicker. Healthcare-associated infections account for an estimated 1.7 million infections and 99,000 deaths each year.
Viruses and bacteria are microscopic, they are everywhere. As a medical profession, we are using outdated thinking to fight them. The science now shows that people moving within a space can cause viruses and bacteria that we thought were only on surfaces to enter the air. They can dry and remain suspended in the air when this happens, increasing the likelihood that we'll breathe them in.
In a hospital setting, however, most infection control protocols focus on contact transmission. As its name implies, contact transmission refers to the spread of diseases through contact with infected surfaces. To mitigate this type of transmission, we wash our hands, aggressively clean surfaces, isolate sick patients, and wear personal protective equipment (PPE).
But the problem with these measures is they have limited ability to combat airborne pathogens, especially those that are the smallest and deadliest. In March 2018, we embarked on a 3-year journey to test a theory: that mitigating the airborne transmission of viruses and bacteria is just as important as, or more important than, measures to reduce contact transmission. St. Mary's Hospital for Children was the laboratory for this experiment. We had no idea at the time that we would soon find ourselves in the midst of a global pandemic.
Three years later, the results are in: the deployment of advanced air purification measures significantly contributed to a 45% reduction in healthcare-associated infections, according to the study recently published in the Journal of Hospital Infection. If we extrapolate those results nationally, it could mean 765,000 fewer hospital infections each year.
This study is novel. To our knowledge, it is one of the few studies -- perhaps the only study -- of an engineering solution to airborne disease transmission conducted in a real-world hospital setting with over 100,000 patient days. Many studies of indoor air quality are conducted in labs or rooms fabricated to mimic the real world. More real-world studies can only advance our knowledge of the most effective tools for air purification.
As promising as these results are for hospitals, they also provide a blueprint for reducing the airborne transmission of diseases in other indoor settings such as schools, restaurants, retail stores, office buildings, nursing homes, and more. Indeed, we focus most of our time on cleaning the world we can see, the surfaces we touch, and not nearly enough energy on the world we can't see -- the air we breathe.
Air quality demands more of our attention. The World Health Organization (WHO) recently tightened its guidance on air pollutants, citing clear evidence of the damage poor air quality inflicts on human health. The WHO makes the case that air pollutants need to be treated the same as other major health crises such as tobacco use and unhealthy diets. This is bad news for Americans who spend 90% of our time indoors where pollutants are two to five times more concentrated than outdoors.
While it is harder to tackle an invisible problem, we must trust the science and lean into technological advancements that can protect us. If one hospital in Queens is any indication, a new national focus on indoor air quality could put the current pandemic behind us and help prevent the next one -- all while making us healthier in general. That, you might say, is a breath of fresh air.
Mark Ereth, MD, MA, is an emeritus professor at the Mayo Clinic College of Medicine and Science and serves as the chief medical officer of SecureAire Technologies. Edwin Simpser, MD, is the president and chief executive officer of St. Mary's Healthcare System for Children in Queens, New York.