Back in March, shortly after our country started going on lockdown and into quarantines due to COVID-19, I wrote a blog reassuring hog producers that they have already been practicing most of the measures being preached to stop the spread of this human coronavirus. Only thing is, producers have long been implementing these practices to keep their livestock safe.
I wrote, "Hog producers have long been flattening the curve in efforts to keep their herd and the U.S. swine population free from various pathogens and viruses. Herd isolation and biosecurity are methods practiced or at least attempted on U.S. pig farms. So, expanding these practices to their family life is nothing new."
Years of research in the swine industry have shown the effectiveness of ventilation and filtration in keeping hogs healthy and reducing the spread of pathogens from farm-to-farm.
Meanwhile, businesses and schools have been shut down to prevent the spread of COVID-19. Businesses have been slow to reopen, and some have struggled to stay open, as breaks of viral infections among workers and customers have reappeared.
State and federal officials struggle with the decision of reopening schools this fall, and if/when they do start up, what will the delivery of education look like? Will it be in-person, all distance learning or a hybrid of the two? Time will tell.
One again, the hog industry may hold a possible solution to getting businesses and schools opened and running smoothly and safely.
The University of Minnesota today posted a report of work done by researchers in the school's College of Science and Engineering analyzing how the coronavirus spreads indoors.
"Mechanical engineering associate professor Jiarong Hong and assistant professor Suo Yang modeled the airborne virus transmission through aerosols, which are ejected from our mouths when we exhale or speak. The researchers found that when an infected person does this, the SARS CoV-2 virus hitches a ride on those aerosols as they land on nearby surfaces or are inhaled by another person," the U of Minn. report says.
"Using precise experimental measurements of aerosols released by eight asymptomatic individuals with COVID-19, the researchers were able to numerically model the external flow of the virus through the air in three interior spaces — an elevator, a classroom and a supermarket. Then, they compared how the virus faired among different levels of ventilation and with different spacing among the rooms' occupants," the report goes on to say.
Hong says in the report, "In general, this is the first quantitative risk assessment of the spatial variation of risks in indoor environments. You see a lot of people talking about what the risks are of staying in confined spaces, but nobody gives a quantitative number. I think the major contribution we've made is combining very accurate measurements and computational fluid dynamics simulation to provide a very quantitative estimate of the risks."
"The researchers found that in indoor spaces, good ventilation will filter some of the virus out of the air, but may leave more viral particles on surfaces. In the classroom setting, after running a 50-minute simulation with an asymptomatic teacher consistently talking, the researchers found that only 10% of the aerosols were filtered out. The majority of the particles were instead deposited on the walls," the report says.
The U of Minn. research models may present opportunities, at least for classroom situations, to take a look at classroom design in location relation to the source of ventilation. Air vents cannot be easily moved, but moving the main source of aerosol production (the teacher) may help in creating a healthy classroom. According to the report, "The virus aerosols spread significantly less throughout the room when the teacher — who is likely doing the most talking — was placed directly under an air vent. This insight could inform how classrooms are arranged and disinfected, and also help places like theaters and concert venues reopen with the proper precautions."
The U of Minn. researchers have joined a task force of international experts to determine how much of the coronavirus is needed to be infectious, as well as being able to "provide science-driven policy that will help mitigate the COVID-19 pandemic."
Once again, approaches researchers on the animal side have determined that when implemented, help to keep the U.S. swine population healthy, may also work in protecting humans. To twist a phrase, what's good for the pig is apparently good for the people.