Coronavirus (COVID-19) is an illness caused by a virus that can spread to person to person. The virus that causes COVID-19 is a new coronavirus, and health experts continue to learn about it every day. At University of Utah Health, doctors and faculty in the Division of Infectious Diseases are conducting their own research and studies to better understand the developing virus.
Sankar Swaminathan, MD, Chief of the Division of Infectious Diseases at University of Utah Health answered questions about COVID-19 and the shared the latest information about what's known about COVID-19 to date.
The World Health Organization (WHO) recently clarified comments on asymptomatic spread of COVID-19. What is known about asymptomatic transmission?
We are starting to realize that there are more people who may be infected with COVID-19 and shed the virus but do not exhibit any symptoms. The person may also be infected, have mild or cold-like symptoms, and not even recognize it as a problem. During that time, before and during those mild symptoms, they may be shedding the virus. We don't know the percentage of people who are infected that don't have symptoms or have mild symptoms because we generally don't test people who appear perfectly fine. Depending on the population, we think anywhere from 20% to 50% of infected people may only have mild or no symptoms.
What makes COVID-19 unique as a virus?
When SARS took place 15 years ago, there was limited transmission and much of it occurred from very sick people in the hospital. That's believed to be one of the differences between SARS and COVID-19. With COVID-19, there's more transmission in the community. One of the reasons this has been a worldwide pandemic with a lot of spread and disease is because transmission is easier—and it may be transmitted before people are sick.
There's been a recent rise in COVID-19 cases in Utah.
What does that mean?
The risk of getting infected appears to be increasing in the community. There have been a couple of outbreaks, such as at a meat-packing plant, which spikes the number of cases in just a few days. There is no question that, overall, our test percentage —the number of tests that are positive—has gone up to about 9%. The estimated reproduction rate—the number of new infections that one infected person can cause—is over 1%. Utah is the second- or third-highest in terms of that transmission measure.
The bright spot is there have not been a lot of hospitalizations. The number of hospitalizations isn't accelerating, and we're not predicted to exceed our hospital capacity anytime soon.
Why should people be more cautious now than at the start of the COVID-19 pandemic?
When the state moved from red to orange and orange to yellow, that was a societal decision to get back to work and keep the economy going. That does not mean the risk has decreased. In fact, the risk has increased. When the state moved from orange to yellow, restrictions were relaxed, and people were allowed to mingle and eat at a place outside. This also means the rate of transmitting disease goes up. We should be much more careful as we transition from orange to yellow; that includes wearing masks and frequently washing hands. We need to be more careful, not less.
Should people be concerned about COVID-19 when they head back to work?
The risk in an office environment are the same risks as anywhere else. You're putting yourself in proximity to more people. If a person was completely isolated in a cave or bubble, then they couldn't get it. If they're isolating at home with their immediate family and no one goes out in public, they're safe. If they interact with one person who goes to work and comes back, there's a risk they're going to bring it in. If they go to work and there are 20 people in an office, the risk will be even greater. We know that, in the hospital, when we are taking care of people who have disease, we are able to use good precautions and have very little transmission from sick patients. The risks are all dependent on how good the control measures are at your place of work.
Does air circulation impact transmission?
Good ventilation is beneficial. The more air exchange, the less likely viruses will build up in a room. There's no real evidence that COVID-19 is spread through air conditioning systems. In fact, most air conditioning systems in buildings will reduce, rather than increase, your risk of getting infected because the systems are vented outside and circulated through HEPA filters.
Do those who become sick with COVID-19 develop immunity?
We don't know. In some people, there are markers in their blood that suggest they are protected. How long that protection lasts and how strong the protection is not known. We don't have any firm evidence that people are getting re-infected to date. If someone fully recovers and they're not infectious, they could still have a positive test result for some time. The test is not measuring live virus. It's measuring the viral genetic material, which can persist for weeks. We generally are not retesting people once they are clinically better because that test may be positive, although it's believed they aren't capable of transmitting the disease.
Previously, a person could exhibit symptoms for up to 14 days. Is that still true?
The majority of people will develop symptoms before that time. The median time from infection to symptoms is about five to six days. The further someone gets from six days, the less likely they are going to develop the disease. After 10 days, it becomes very unlikely. And after 14 days, it's not likely at all.
Are restaurants, movie theaters, and churches safe right now?
The decision to go to one of these places can increase your risk to COVID-19. When someone goes into an enclosed space, consider the number of people, the smallness of the space, and the length of time that's spent there. Those three factors will increase your risk. If you go into a movie theater and watch a three-hour movie with a bunch of people, even if you are six feet apart, the risk is greater than taking a walk in the park. Same thing is true with a restaurant if you eat inside. It's all a calculated risk.
When will we know if protests impacted our COVID-19 cases in Utah?
There's a curve to exposure. If someone became exposed to COVID-19 at a protest, we expect to start seeing cases as early as three days and possibly out to 14 days. Most people develop symptoms within a week or so. Most people don't see COVID-19 symptoms until they have had symptoms for a few days.
How can protests be done safely in a COVID-19 pandemic?
It's a very unpredictable situation when a lot of people are in the street together. People could get stuck in an enclosed space with others. Shouting and yelling also generates a lot of particles. Even while wearing a mask in close proximity with others, you're not 100% protected by any means. Keeping a mask on would be helpful, but you can't control what other people do. Other protestors may not wear a mask, which could increase your risk. If you are in a high-risk group, you should reconsider participation.
What's some advice for schools in the fall?
Whatever shape the return to classes takes, it's going to require a continuation of these sort of interventions such as masking and practicing frequent hygiene. COVID-19 isn't going to miraculously go away between now and when school starts.
Most young people are at relatively low risk of serious illness or death. However, not every young person is completely healthy and risk-free. Some students may have cancer, diabetes, severe asthma, or have immune suppressive conditions. Older adults that are faculty or teach are also considered high-risk.
We need to take measures to protect others as much as possible in these situations. Some institutions are thinking about hybrid classes so that some classes can still have hands-on learning. In these situations, there should be attempts to minimize high-risk transmission settings.
As warning levels are ramped down in Utah, what personal responsibility does an individual have to make these calls?
No governmental directive is going to be successful without the support of the people. That said, no one is saying we don't have a responsibility to do whatever we can to prevent spread. What we do for fellow community members is ultimately to our own benefit as well. It's personal responsibility, but the government has made it clear we need to do this as a community. Masking is one example; it's not foolproof or 100% effective, but we do know it reduces the likelihood of COVID-19 spread.