I attended medical school during the early days of the HIV pandemic. HIV transformed the subspecialty of infectious disease and hospital care, introducing the concept of “universal precautions”. Essentially we assume everyone is a potential vector and behave accordingly.
Over the years other infectious organisms became prominent in hospitals, such as antibiotic resistance bacterial strains and C. dif. Respiratory viral epidemics became more common as well. Each time new protocols were put in place to reduce the spread of infection around the hospital, and each time those new measures were here to stay. Now, when I am covering the consult service and have to roam around the hospital seeing patients, you have to look above the door to see what restrictions are in place. About half the time I have to gown and glove to enter the patient’s room.
During the recent COVID pandemic other precautions were put in place – universal masking with extra precautions for those known to have COVID, such as N-95 masks, gown, glove, and face shield. I knew these new measures would never go away, even once the pandemic of officially over. But did these measures actually work to prevent the spread of COVID in health care settings?
Spoiler alert – yes, absolutely. Anecdotally the effect was profound. On average I tend to get 2-3 respiratory infections per year (a bit more when I had kids in school living at home). Such infections are an occupational hazard but also just a life hazard, unless you live and work in a remote area. But during the COVID pandemic, with universal masking and other precautions, I went two and a half years without a sniffle. Within a week of universal mandatory masking being lifted from the hospital where I work being lifted, I got my first cold since the start of the pandemic.
As impressive as this is, this is SBM and we don’t rely on anecdotes alone. There is plenty of objective data to show that masking and social distancing work to prevent respiratory viruses. One of the most impressive is the flu data. When the COVID shutdown began, that abruptly ended the 2019-2020 flu season. During the height of the pandemic, flu cases in the US dropped from an annual average of about 35 million cases to only 9 million cases in 2021-2022. There are no estimates for 2020-2021 because there were so few cases. In 2022-2023 the flu was back up to 31 million cases. This result is unambiguous.
What about for COVID itself? This is a new virus with a single pandemic, so we don’t have the kind of data that we have for recurrent flu seasons. We need to make more sophisticated epidemiological comparisons to see how specific measures worked. Just such an analysis was recently published in the journal Clinical Infectious Diseases. Here is what they did:
We performed retrospective cross-sectional analyses of viral genomics from all available SARS-CoV-2 viral samples collected at UC San Diego Health and social network analysis using the electronic medical record to derive temporospatial overlap of infections among related viromes and supplemented with contact tracing data.
This is a uniquely powerful analysis because of the combination of techniques they used. They relied mostly on genomic analysis – studying the specific genetic variants of the specific strain of the virus that individuals were infected with as a way of reverse engineering the spread of the virus. However, during the first Omicron wave the virus strains that were spreading were too similar to rely entirely on this method. So they supplemented with contact tracing.
What they found was that the COVID virus spread very little within patient care settings even during the height of the pandemic. When the virus did spread it did so outside of patient care settings – so in the cafeteria, not in the patient room.
This strongly suggests that the measures put into place to prevent the spread of SARS-CoV-2 during patient care were very effective. This strengthens the case for what I assumed would happen anyway – keeping these measures even outside the context of a pandemic.
In the past year many health care systems (such as my own hospital) relaxed the mandatory masking requirements in the patient care setting, but are now reinstituting some of them. For example, where I work healthcare workers are required to mask during all patient encounters, while patients are encouraged to mask if they do not have symptoms and required to mask if they do have symptoms.
When masking requirements were relaxed, we started to see the return of COVID transmissions. And now that flu season is upon us, we are again seeing the “tripledemic” of COVID, the flu, and RSV. There are also the usual regular cold viruses going around.
This is simply the world we now live in. Population sizes, concentration in cities, global travel, and increasing encroaching on wild spaces has created a perfect storm of infectious diseases. We simply need to recognize this new reality and up our game.
This may be a positive side effect of the COVID pandemic – at least we now have a “masking infrastructure” in place. People know how to access and use masks when appropriate. There is also more social pressure not to go out into the public when one is sick, coughing and sneezing. Hand hygiene is also important. And for hospitals, infectious precautions have ratcheted up another couple of notches, and perhaps we should not ever relax them.
The political nonsense around masking also needs to end. Masks are not a political statement. They are an effective and essential measure of limiting the spread of respiratory viruses in a world increasingly plagued by them. And it’s only going to get worse.
