R-0 may be the most important scientific term you̵

7;ve never heard of when it comes to stopping the coronavirus pandemic.


Officials have been able to control COVID-19 transmission rates by introducing guidelines encouraging residents to eat and drink outside, exercise, and hang out with friends and loved ones from a safe distance.

But health experts fear cases could rise again as cooler temperatures in fall and winter force people back inside.

The nation’s leading expert on infectious diseases, Dr. Anthony Fauci, is also concerned that upcoming holiday celebrations could increase transmission rates and advised Americans not to skip big Thanksgiving plans.

Speaking to the CBS Evening News on Wednesday, Fauci warned against gathering with large groups of guests outside the city in an indoor area. “It’s unfortunate because this is such a sacred part of American tradition – the family that gathers around Thanksgiving,” he said. But that’s a risk. ”

Some experts suggest that indoor transmission fueled the summer surge in COVID-19 cases in the southern states as residents retreated to air-conditioned public places to escape the heat. The three most populous states – California, Texas, and Florida – each had more than 500,000 infections at the peak of the surge in August, according to Johns Hopkins.

“Public spaces are one of the places where there is likely to be the greatest risk and transmission,” said William Hanage, associate professor of epidemiology and faculty member at the Center for Communicable Disease Dynamics at Harvard TH Chan School of Healthcare.

What makes indoor gathering dangerous and how can you stay safe?

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New York City reached a recovery milestone on Wednesday as it allowed an indoor restaurant for the first time since March. (April, 30th)

AP domestic

“A minority of infections leads to the majority of transmission”

Dr. Lewis Nelson, professor and chair of emergency medicine at Rutgers New Jersey Medical School, said one of the main reasons for a higher risk of transmission indoors than outdoors is poor ventilation.

Natural air currents outside disperse virus particles faster and more effectively than inside. There is minimal to no air circulation indoors, so virus particles can remain in the air or fall on touch-sensitive surfaces.

“If I smoked a cigarette (inside) you’d see the smoke particles lingering,” he said. “While outdoors the smoke kind of leaves.”

In addition, indoor public spaces have more surfaces. When breath droplets or aerosol particles fall, they land on table tops, chairs, door handles and other objects that people frequently touch.

“Outdoors have fewer surfaces,” said Nelson. “Nobody touches the ground and then their eyes, nose or mouth.”

People are also closer indoors because they are bounded by walls. According to Hanage, bars are an important source of transmission in communities as people congregate there for long periods of time as judgment is compromised by the consumption of alcohol.

According to the U.S. Centers for Disease Control and Prevention, adults with confirmed COVID-19 had dinner at a restaurant twice as likely as those who tested negative in the 14 days prior to their illness.

Positive patients were also more likely to report going to a bar or coffee shop when analysis was limited to those who have not had close contact with people known to have the coronavirus.

“A minority of infections lead to much of the transmission,” he said. “Of course, when you’re in a bar, that cluster is much bigger as more people gather.”

How to increase airflow and ventilation indoors

Experts agree that increasing the airflow indoors is important to reduce the risk of transmission, as it will prevent virus particles from hanging in the air for too long.

The ventilation rate is the volume of outside air per unit of time and air exchange rateAccording to Shelly Miller, professor of mechanical engineering at the University of Colorado Boulder, the ventilation rate of a room is divided by the volume of that room.

Most air conditioning and heating systems direct about 20% of the fresh air into a building, while the remaining 80% is circulated for reasons of energy efficiency.

However, ventilation can be increased by opening a window and turning on a fan. Most portable air filters cannot filter out airborne virus particles, but they do facilitate the air circulation that spreads the virus. Air purifiers with HEPA filtration remove more than 99 percent of the particles in the air regardless of the particle size and facilitate air circulation.

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“If you can get rid of airborne viruses quickly, you reduce the risk of transmission,” Miller said.

While UVC devices are helpful for commercial buildings like offices and schools, experts recommend sticking to a simple fan or portable air filter for home use as some disinfection devices can be harmful if used improperly.

Another great way to reduce the risk of transmission is to limit the number of people in a room, which all contributes to better indoor air quality.

“Now if I reduce the number of students from 35 to 17, the ventilation will provide twice as much outside air per person and that’s great,” said Miller.

The construction consultancy BranchPattern has developed an online calculator that determines the risk of transmission by entering room characteristics such as heating, ventilation, the number and duration of the room in the room. The user can also add parameters such as wearing masks and wearable filters.

Back to basics: masks, social distancing, and hand hygiene

Experts say the best way to be safe indoors is to take three basic mitigation measures: masks, social distancing, and hand hygiene.

Hopefully, if you put all of these things together and put them into practice, it should slow down transfer rates, “Hanage said.

Masks are especially important. CDC Director Robert R. Redfield told a Senate committee in mid-September that a vaccine may not be available to the American public until the summer or fall of 2021 and that masks are “the most important and powerful public health tool we have” – possibly even more effective than a vaccine.

Dr. Sunil Sood, an infectious disease specialist at Northwell Health’s South Shore University Hospital in Bay Shore, New York, said guests should wear masks even when eating outside.

“It’s annoying … (but) you just have to do it,” he said. “The only time you should take your mask off is when you actually bite and chew.”


Here are 3 solutions to help you fix those pesky face mask problems.


This means that you keep the mask on while you chat with other guests, wait for food, and talk to your waiter.

Dr. Chad Asplund, professor of family medicine and orthopedics at Mayo Clinic, said those guidelines also apply to the gym.

He recommends always wearing a mask, machine-wiping, and hands washing. He also advises against using some fitness equipment such as yoga mats and blocks.

“When you do intervals, it becomes harder to wear a mask,” Asplund said. “You might want to get creative when you’re usually out and about because there are definitely times (when it’s crowded) before and after work.”

For social distancing, the Colorado Health Department has developed an online tool that calculates the risk of transmission based on the total area of ​​the room and the objects in the room to determine how many people can be there safely at the same time.

Keep an eye on the community’s transfer rates

While wearing masks, social distancing, hand hygiene, and increased airflow can reduce the risk of indoor transmission, these mitigation measures are not 100% effective, especially when transmission rates are high in the community.

Barry Bloom, research professor of public health and former dean of Harvard TH Chan School of Public Health, recommends residents keep an eye on transmission rates in their area to determine if it is safe to go into a public setting.

“When (the rates) are high, as is the case in many parts of the state, it is just asking for trouble,” he said.

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According to Bloom, this is happening in the UK, where the number of confirmed COVID-19 cases has more than tripled in the past three weeks and infection rates have increased across all age groups and regions.

British Prime Minister Boris Johnson unveiled a new system on Monday that included increasingly stringent measures to slow the spread of the virus three weeks after a nationwide program that banned gatherings of more than six people and called for pubs and restaurants to close early.

“It makes a big difference whether you are in a low-speed or high-speed environment in how much flexibility you have to stay safe,” said Bloom.

Featuring: Ramon Padilla, USA TODAY; Associated Press. Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.

US TODAY health and patient safety coverage is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide any editorial contributions.

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