A blog post by an infectious disease professor who compiled easy to understand science on where and how coronavirus spreads has gone viral with over 8 million views since it was published 5 days ago.
Professor Erin Bromage from the University of Massachusetts Dartmouth wrote a blog post called, “The Risks — Know Them — Avoid Them“. It informs on how to weigh risks amid the re-opening of businesses and other places where people congregate as state leaders try to save the economy during an ongoing public health crisis.
Dr. Bromage put together information from various coronavirus studies and his own understanding of infectious disease — but he says he’s not an expert.
I am not holding myself out as an expert on this virus or epidemiology and I rely on the amazing scientists publishing and discussing their work for the material and data content of my posts. These scientists are the true rock-stars of the response to COVID-19. I just enjoy being able to translate their data and findings into prose that non-scientist lay people can more readily understand as we navigate through this pandemic.
The professor wrote that his background is actually in the “epidemiology of, and immunity to, infectious disease in animals,” but he said the classes he teaches usually focus on infection and immunity in humans.
Still, the information in his blog hit a nerve judging from the viral spread of his post.
Dr. Bromage Said Social Distancing Doesn’t Work Indoors if People Are in the Same Space for Hours
According to the professor, acquiring COVID-19 is all about exposure to the virus plus time, which is why most people get the virus from someone they live with. However, in the community, contact tracing studies have shown that the most common places people have been infected are workspaces, indoor restaurants, birthday parties/ funerals/weddings, face-to-face business networking events, indoor sports events, and places like choir spaces where singing expels more than usual respiratory droplets that can easily enter the bodies of others nearby.
Bromage writes, “while the exact number of people infected by respiratory droplets / respiratory exposure versus fomite transmission (door handles, shared water coolers, elevator buttons etc) is unknown, it serves to highlight that being in an enclosed space, sharing the same air for a prolonged period increases your chances of exposure and infection.
The blog post highlights stories of rampant spread discovered through contact tracing, including the plight of meatpacking workers who have been hit hard by the virus due to the close-quarters and poor ventilation that those employees traditionally work in.
“There are now outbreaks in 115 facilities across 23 states, 5000+ workers infected, with 20 dead,” Bromage wrote.
COVID-19 Transmission is Lowest in Open Spaces & Indoor Places with Good Ventilation
According to Bromage, “Social distancing rules are really to protect you with brief exposures or outdoor exposures. In these situations there is not enough time to achieve the infectious viral load when you are standing 6 feet apart or where wind and the infinite outdoor space for viral dilution reduces viral load.”
Bromage says so far the science seems to point toward outdoors and ventilated spaces as the safest places to be to avoid catching or spreading COVID019. “The effects of sunlight, heat, and humidity on viral survival, all serve to minimize the risk to everyone when outside,” he wrote.
A preprinted study out of China published in April found that out of thousands of cases of COVID-19 they traced, only one was found to have been transferred outdoors.
According to Bromage, the thing to keep in mind is “dose and time.” He writes that if a person walks by you outside, “you would have to be in their airstream for 5+ minutes for a chance of infection. While joggers may be releasing more virus due to deep breathing, remember the exposure time is also less due to their speed.”
The Professor Gives Tips on How to Assess an Environment Regarding Odds of Catching Coronavirus
According to Bromage, people can size up a situation and weigh the risks of potentially getting infected with COVID-19 as we move forward with re-opening various places where people congregate, pointing out that the grocery store isn’t the hotbed of COVID-19 that people think it is…unless you are an employee.
When assessing the risk of infection (via respiration) at the grocery store or mall, you need to consider the volume of the air space (very large), the number of people (restricted), how long people are spending in the store (workers – all day; customers – an hour). Taken together, for a person shopping: the low density, high air volume of the store, along with the restricted time you spend in the store, means that the opportunity to receive an infectious dose is low. But, for the store worker, the extended time they spend in the store provides a greater opportunity to receive the infectious dose and therefore the job becomes more risky.
As people return to work in any industry, there are things to consider to make an informed assessment of their risk. Bromage writes:
Basically, as the work closures are loosened, and we start to venture out more, possibly even resuming in-office activities, you need to look at your environment and make judgments. How many people are here, how much airflow is there around me, and how long will I be in this environment? If you are in an open floorplan office, you really need critically assess the risk (volume, people, and airflow). If you are in a job that requires face-to-face talking or even worse, yelling, you need to assess the risk.
Bromage also says that while his blog post focuses on the respiratory risks, surface risks are a risk too because coronavirus is known to live on surfaces for extended amounts of time, so the mantra of washing your hands and not touching your face are also very important to continue. He also suggests wearing masks, saying the risk for infection is still very significant.
“Even if you are gung-ho for reopening and resuming business as usual, do your part and wear a mask to reduce what you release into the environment. It will help everyone, including your own business,” Bromage writes.
Board Certified Emergency Medicine Doctor Shannon Sovndal told Heavy in a recent interview that while he sees the importance of getting the economy back on track and reopening, it’s important to take personal responsibility in not spreading the virus.
Sovndal pointed out that we don’t know enough about the virus and do not have good data due to a severe lack of testing, but we do know that universal precautions work in slowing the spread of viruses.
He said, “I don’t know what the virus does for sure yet because I don’t have the data. But I do know the universal precautions are wearing a mask, protecting your face…and I need to wash my hands frequently.”
The doctor said that even if we all do our part we will still have COVID-19 cases but it will be on a lesser scale, “We can get our economy back online — which I totally agree with does have ramifications as well…you have to look at the whole picture and you have to mitigate your risk where you can.”
Professor Bromage says something similar in his now-viral blog post, saying that he wrote it in an effort to give people information to work with as we try to go back to a semblance of pre-pandemic life.
“Throughout most of the country we are going to add fuel to the viral fire by reopening,” he writes. “It’s going to happen if I like it or not, so my goal here is to try to guide you away from situations of high risk.”