Archived: What you need to know about the novel coronavirus

Editor's Note, June 1: This article is no longer being updated. Get the latest COVID-19 news here. Visit our Minnesota COVID-19 tracker for data related to cases and vaccinations. Information about vaccines and Minnesota's vaccination program is available here. You can find answers to more reader questions here.

Yes, the CDC recommends that people wear masks in public settings, at events and gatherings, and anywhere they will be around other people. Starting Feb. 2, 2021, masks are required on planes, buses, trains, and other forms of public transportation traveling into, within, or out of the United States and in U.S. transportation hubs such as airports and stations.

The Centers for Disease Control encourages people to use coverings such as homemade masks and bandannas for their faces while outside their homes. In addition, many cities and private businesses and some states require face coverings to be worn to reduce the odds of transmission.

Simple cloth masks that cover the mouth and nose can prevent virus transmission from individuals when they are out buying groceries or seeking medical care.

READ: How to make a face mask without sewing a stitch.

COVID-19 is a respiratory disease, much like influenza, and the precautions used to fight influenza are the same ones that people should be using to stave off coronavirus and other respiratory diseases, said Timothy Brewer, a professor of epidemiology and medicine at UCLA's Fielding School of Public Health.

- Wash your hands regularly

- Cover your nose and mouth when you sneeze

- Stay home from work or school when you're sick

- Drink lots of fluids

Washing your hands with soap and water is the most effective way to protect yourself, according to the Centers for Disease Control and Prevention. "But if soap and water are not available, using a hand sanitizer with at least 60% alcohol can help you avoid getting sick and spreading germs to others," the agency says on its website. Sanitizers do not eliminate all types of germs and they are less effective if your hands are visibly dirty or greasy.

"It is very important when you use hand sanitizer that you use an adequate amount and you cover all of the surfaces of your hands," said Dr. Alison Peterson, vice president of medical affairs at Allina Health's United Hospital in St. Paul. Also, let your hands dry before touching anything. Apart from cleaning your hands, remember not to touch your face, something that is often easier said than done.

PODCAST: What you need to know about the coronavirus pandemic now.

"Flattening the curve" is an expression used to explain how slowing the exponential growth in a disease's spread can allow a country's health system to better cope with the surge in cases so that it isn't overwhelmed.

While the novel coronavirus pandemic might eventually infect a majority of people in the United States, the speed at which the outbreak spreads makes a huge difference in health outcomes. What epidemiologists fear is that the U.S. health system would become overwhelmed by a sudden surge that requires more people to be hospitalized than can be handled, both from a personnel and equipment standpoint. In a scenario of uncontrolled growth, more people would die simply because there might not be enough doctors, nurses, hospital beds or ventilators for people who need them.

"If you look at the curves of outbreaks, they go big peaks, and then come down. What we need to do is flatten that down," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

Flattening the curve means that the social distancing measures being deployed in places like Italy and South Korea and now in the United States aren't so much about preventing illness but rather slowing down the rate at which people get sick, according to Vox.

Without any measures to slow it down, COVID-19 will spread exponentially for months. An interactive simulation by the Washington Post shows how the spread can be slowed by use of "social distancing," avoiding public spaces and large group gatherings that can increase the rapid spread of COVID-19.

People sickened by COVID-19 are most infectious when they are showing symptoms, including fever, coughing and shortness of breath, according to the Centers for Disease Control and Prevention.

But new research confirms that those without symptoms are playing a significant role in spreading the virus. A study of cruise ship passengers found that nearly 18 percent of them tested positive and had no symptoms. State of Minnesota and University of Minnesota researchers modeling the pandemic's effects now estimate that one infected person is spreading it to as many as four others. That's up from two to three transmissions per infected person, reflecting the greater role of asymptomatic transmission, according to Minnesota Health Commissioner Jan Malcolm.

That's why public health officials recently changed guidelines on masks to suggest that people who are out in public should wear a homemade mask to lower the chances that they will make someone else sick.

The virus is still thought to be primarily transmitted by breathing in the respiratory droplets released by an infected individual.

"Person-to-person transmission occurs when an individual with the infection emits droplets containing virus particles while coughing, sneezing, and talking," according to a recent article published on the Journal of the American Medical Association website.

The virus can also exist on surfaces. "Survival of the virus on innate surfaces has been an important topic of discussion. While there are few data, the available evidence suggests that the virus can remain infectious on inanimate surfaces at room temperature for up to 9 days," the JAMA article said. That's why it is important to wash your hands and try to avoid touching your face.

After a person recovers, it is unclear how long they remain contagious. Genetic material of the virus may be detectable up to two weeks after infection, but that "does not necessarily mean that infectious virus is present," according to the CDC.

It really depends on how bad the symptoms are and whether any serious complications develop. "About 80% are mildly to moderately symptomatic," said Dr. Timothy Sielaff, chief medical officer at Allina Health. "That can mean fever, cough, muscle aches and lethargy, which last a few days and improve over several more; typically 2 weeks or so."

These mild cases can recover at home because there is no treatment for COVID-19.

When complications develop, such as pneumonia, hospital care may be needed so doctors can monitor symptoms and provide support to stabilize the situation and hopefully keep things from getting worse.

"Severe illness can last longer especially if hospitalization or intensive care is needed; on the order of 3-6 weeks," said Sielaff.

The Minnesota Health Department so far has kept in contact with all people who have tested positive. Each case differs, so recovery depends on the guidance provided by a doctor or a public health official. But generally, people are considered recovered when the symptoms go away.

"If you are sick, we are asking people to stay home for at least seven days and you need to be fever free for at least three days without the aid of fever reducing medications," said Kris Ehresmann, infectious disease director at the Health Department.

The World Health Organization considers two negative COVID-19 tests taken 24 hours apart to be part of its official definition of recover, but a shortage of tests makes that difficult.

"It will be useful to the individual and the community to have negative testing to confirm, but we do not have enough tests available right now," said Dr. Timothy Sielaff, chief medical officer at Allina Health.

The state encourages Minnesotans to get tested for COVID-19. Health officials are working to make it easier to get a COVID-19 test. MDH recently opened a free saliva-testing center at the Minneapolis Convention Center and another at Minneapolis-St. Paul International Airport. Tests are available to anyone who wants one.

MDH also unveiled a new at-home testing program. Minnesotans can order a free saliva test that they can perform at home while being observed by a health worker over a Zoom call. Once completed, the sample is mailed to a laboratory and results should be received by e-mail within 24 to 48 hours.

READ: 6 things you need to know about COVID-19 testing in Minnesota

COVID-19 arrived during peak cold and flu season, and many of the symptoms are the same: fever, cough and sneezing. So based on symptoms alone, it is hard to tell. But this new coronavirus has been known to severely impact the lungs. When we hear someone has shortness of breath, we will have more concern and they will need to be seen, said Dr. Jeff Dichter, a critical care physician at M Health Fairview.

Doctors say that dehydration from vomiting or diarrhea, a severe headache and progressively worsening symptoms also are warning signs. If you have a chronic medical condition that makes you more susceptible to complications from any type of viral infection, such as pneumonia, it is important to seek medical care. One suggestion is to call your clinic to get advice on how to proceed. Many clinics have a nurse who will triage cases, and you will most likely be asked about travel history and symptoms. If the clinic suggests that you see a doctor, staff might meet you at the front door and provide you with a mask to help prevent infecting others.

If COVID-19 does take hold in Minnesota, the health care system is likely to prioritize care for those who are the sickest. The health care system is extremely full right now and always runs close to capacity, said Dr. John Hick, emergency physician and medical director for emergency preparedness at Hennepin Healthcare. Be prepared for longer waits and potentially non-traditional approaches to care. The focus of the health care system will be on taking care of those with severe disease that may require prolonged and intensive care.

READ: Is it the flu, a cold or the new coronavirus?

The Minnesota Hospital Association (MHA) says it is making plans for a possible surge of COVID-19 patients, and is anticipating that 15% of them will need hospital care and 5% will need intensive care. As it stands, the system is already seeing high demand, with more than 95% of beds occupied on one or more days in the Twin Cities metro area in recent weeks, said Dr. Rahul Koranne, MHA chief executive.

Based on its planning, the hospital group has said there could be a need for more intensive care beds, ventilators, masks and other protective equipment for health care workers, as well as for staffing, phone banks to help triage patients, and training on COVID-19. "If there was a challenge to our capacity, hospitals would have to look at constructing additional space for those," said Wendy Burt, MHA spokeswoman. Hospitals and health care systems are working with the Minnesota Health Department to coordinate information about resources.

A novel coronavirus is a new coronavirus that has not been previously identified. Coronaviruses are a large family of viruses. According to the CDC, the virus causing this outbreak is not the same as the coronaviruses that commonly circulate and cause mild illness, such as the common cold. Some coronaviruses cause illnesses in people; others cause viruses in animals such as cattle, camels and bats. Rarely, animal coronaviruses can spread to people. This happened with SARS-CoV and MERS-CoV. The virus that causes COVID-19 likely also originated in an animal and spread to humans, according to the CDC.

The Centers for Disease Control says that it is not yet known whether weather and temperature impact the spread of COVID-19. Some other viruses, like the common cold and flu, spread more during cold weather months but that does not mean it is impossible to become sick with these viruses during warm weather.

Communities in warmer places appear to have a comparative advantage in slowing the transmission of coronavirus infections, according to an early analysis by scientists at the Massachusetts Institute of Technology.

The New York Times published news of the MIT study along with two others that have drawn similar conclusions. But none of the studies have been peer-reviewed by other scientists, and the MIT study's author acknowledged that factors such as travel restrictions, social distancing measures, variations in the availability of tests and hospital burdens might have affected the number of cases in different countries.

The most common method of catching COVID-19 illness is by inhaling respiratory droplets created when an infected person sneezes or coughs, especially through close contact over a sustained time period. "We know that your highest risk is in being close contact with another person who is in their acute phase of infection," said Dr. Alison Peterson of Allina Health's United Hospital. "If a [sick] person coughs into your face that is high risk." However, it is possible that the novel coronavirus could be on surfaces, such as door handles, elevator buttons and other things that get touched frequently. That is why health officials are emphasizing the importance of washing your hands and not touching your face.

"It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads," according to the U.S. Centers for Disease Control.

Ultimately, researchers can't prove that surfaces are totally safe, which is why they ask people to take some precautions for protection from COVID-19 as well as other diseases such as influenza and the common cold. The risk is even lower for packages that are shipped weeks ago or from long distances. "In general, because of poor survivability of these coronaviruses on surfaces, there is likely very low risk of spread from products or packaging that are shipped over a period of days or weeks," according to the CDC. It is good practice to clean surfaces at home using products containing bleach or 70% alcohol. "Wipe down commonly touched surfaces. Use appropriate precautions in your home that would do with the common respiratory illnesses," said Peterson. The Environmental Protection Agency has guidelines for which products to use against SARS-CoV-2.

READ: No, you can't kill coronavirus by drinking warm water. Debunking that viral Facebook post.

Because COVID-19 is still a relatively new human infection, researchers are still learning more about it. "Based on more common circulating coronaviruses, there is some evidence that people can be infected more than once over subsequent years," said Dr. Susan Kline at M Health Fairview. "But I don't think we know yet with this COVID-19." In the 2003 SARS outbreak, which was also caused by a type of coronavirus, there was evidence that the virus was still present in respiratory secretions, blood, urine and tissue "going into three weeks of illness, sometimes even longer among people who are more seriously ill."

While the elderly or those susceptible to pneumonia are encouraged to get that vaccine, it won't protect you against the viral pneumonia that is associated with COVID-19. "The pneumonia vaccine just protects against pneumococcal pneumonia," which is a bacterial infection, said Dr. Susan Kline, infection prevention medical director for M Health Fairview. "But it can't protect against all pneumonia and it does not protect against viral pneumonias."

The CDC says that people should not travel at this time. Travel increases your chance of spreading and getting COVID-19. CDC recommends that you do not travel at this time. If you do plan to travel, the CDC says you should follow these guidelines.

All air passengers coming to the United States, including U.S. citizens, are required to have a negative COVID-19 test result or documentation of recovery from COVID-19 before they board a flight to the United States, according to the CDC.

Masks are required on planes, buses, trains, and other forms of public transportation traveling into, within, or out of the United States and in U.S. transportation hubs such as airports and stations.

READ: What you need to know about Minnesota's COVID-19 restrictions

In an effort to curb the spread of the coronavirus, Metro Transit has suspended nighttime light rail service.

Service on the Green and Blue lines was suspended between 9 p.m. and 6 a.m. in an effort to also address "operational challenges." Evening trips on light rail that begin before 9 p.m. will complete their trips, Metro Transit said.

The Blue Line airport shuttle between Terminal 1 (Lindbergh) and Terminal 2 (Humphrey) at the Minneapolis-St. Paul International Airport will continue to operate overnight.

Regular bus service will continue to be suspended between 11 p.m. and 4:30 a.m. And earlier this week, Metro Transit suggested that passengers wear a mask or face covering while aboard all buses. Only 10 bus passengers will be permitted on 40-foot buses, and 15 on 60-foot buses.

Metro Transit advises that public transportation should be used for essential purposes only.

Metro Transit says buses, trains and facilities are being regularly disinfected. Customer service information is available at 612-373-3333 between 6:30 a.m. and 9 p.m. weekdays and 8 a.m. and 4:30 p.m. on weekends. Riders are encouraged to use the Show My Bus feature on mobile or desktop websites.

A report from the U.S. Centers for Disease Control and Prevention examined more than 7,000 U.S. cases of COVID-19 and reaffirmed the risks to the sick and elderly. People with at least one underlying condition, such as diabetes, represented 37% of overall COVID-19 patients, but 78% of those needing intensive hospital care. Just being older than 65 was a risk factor for needing intensive care.

According to the U's Center for Infectious Disease Research and Policy, a team from the United Kingdom published a new case-fatality rate estimate of 1.4%, based on all available data on deaths in and outside of China.

COVID-19 is more fatal than the seasonal flu, but not as deadly as some other viruses. "We've certainly seen infectious diseases in fairly recent memory that are much more lethal than COVID-19 at this point," said Minnesota Health Commissioner Jan Malcolm.

Ebola, which primarily has affected African countries, had a fatality rate of 50%. COVID-19 is the name of the illness caused by exposure to the SARS-CoV-2 virus. Recent estimates have suggested a fatality rate between 1.4% and 3.4%. The flu's death rate is about 0.1%. By comparison, two other coronavirus-type outbreaks were more fatal: 10% for the 2003 SARS outbreak, which also started in China, and 30% for the 2012 MERS outbreak, which was confined to the Arabian Peninsula.

The COVID-19 fatality rate was determined by a study of nearly 45,000 patients conducted by China's disease control agency. That number is likely to change as other studies are conducted and more is known is about the number of mild cases. However, like the flu, the elderly and those with chronic health conditions that affect their ability to fight off infection have higher mortality rates. According to the Chinese study, 81% of cases were mild, while 14% had more severe infections and 5% needed intensive hospital care, a group that saw higher death rates. "When the disease is severe, it can be quite severe," Malcolm said.

The CDC offers guidance to those who are at risk for serious illness with COVID-19, including older adults and those with heart disease, diabetes or lung disease. In addition, if you have another chronic health problem, cancer or are immune-compromised, doctors suggest extra caution.

Not everyone with the virus will exhibit symptoms, and about 80 percent of people with the virus do not end up needing hospitalization, health experts say.

Janet Moore contributed to this report. This article also includes information from the Washington Post and Associated Press.