[Originally published: January 29, 2020. Updated: October 28, 2020.]
COVID-19 upended daily life in the United States this year as SARS-CoV-2, the virus spreading the disease, swept across the country. The U.S. declared a national emergency in March, and Americans adjusted to strict guidelines, cancelled activities and closures, and mandates to stay home. Now some people have returned to work and schools are implementing strategies for reopening safely. But the conversation continues about how to avoid new surges of COVID-19 infections.
“Until an effective vaccine against COVID-19 is available, we have to continue to do the hard, albeit tedious, work of keeping ourselves safe and healthy—by wearing facial coverings, keeping our social distance, practicing good hand hygiene, and staying home when we’re sick,” says Jaimie Meyer, MD, MS, a Yale Medicine infectious disease specialist.
SARS-CoV-2 is a virus that scientists haven’t seen before. Like other viruses, it is believed to have started in animals and spread to humans. Animal-to-person spread was suspected after the initial outbreak in December among people who had a link to a large seafood and live animal market in Wuhan, China.
By January, clusters of cases of a mysterious pneumonia were being reported in Wuhan, and in the following weeks person-to-person spread of the virus was reported around the world. In early March, the World Health Organization (WHO) declared COVID-19 a pandemic—a disease outbreak occurring over a wide geographic area and affecting an exceptionally high proportion of the population.
Scientists and public health officials are working as quickly as possible to find answers to key questions about how the disease is transmitted and why some cases are more severe than others, while they investigate treatments and a potential vaccine.
Below is a list of five things you should know about the coronavirus outbreak.
1. What we know about COVID-19 is changing rapidly
The number of people infected by the disease continues to change every day. While the impact of the disease varies by location, there are now more than 43.7 million confirmed cases of people with COVID-19 around the globe and more than 1.1 million people have died from the disease, according to the WHO. (While some news sources report different numbers, the WHO provides official counts of confirmed cases once a day.)
The Centers for Disease Control and Prevention (CDC) provides a rough picture of the outbreak in the U.S. here, currently putting the total confirmed and probable cases at more than 8.7 million, and estimating almost 226,000 deaths. (If there are any discrepancies, data provided by state public health departments should be considered the most up to date, according to the agency).
The term coronavirus includes a family of seven known viruses that cause respiratory tract illnesses that range from the common cold to such potentially deadly illnesses as severe acute respiratory syndrome (SARS), which killed almost 800 people during an epidemic that occurred in 2002 and 2003. COVID-19 is the first pandemic known to be caused by the emergence of a new coronavirus—novel influenza viruses caused four pandemics in the last century (which is why the response to the new disease is being adapted from existing guidance developed in anticipation of an influenza pandemic).
According to the CDC, reported COVID-19 illnesses have ranged from mild (with no reported symptoms in some cases) to severe to the point of requiring hospitalization, intensive care, and/or a ventilator. And, in some cases, COVID-19 illnesses can lead to death. The risk for severe illness increases with age (so people in their 50s are at higher risk for severe illness than those in their 40s, and those in their 60s and 70s are at higher risk, generally, than those in their 50s. People ages 85 and older are at the greatest risk. People living in a nursing home or long-term care facility, and people of all ages with underlying health conditions (such as diabetes, heart disease, lung disease, and obesity) also are at high risk for serious illness.
Doctors are still working to develop a complete clinical picture of COVID-19. “I think there are two main questions,” says Richard Martinello, MD, a Yale Medicine infectious diseases specialist and medical director of infection prevention at Yale New Haven Health. “First, we need to know how this virus is transmitted between people so we can be more precise in our efforts to stop its spread. Data is needed not only to better understand when those who become ill shed the virus, but also which body fluids contain the virus and how those may contaminate surfaces and even the air surrounding them,” says Dr. Martinello. “Second, there needs to be a better understanding of the pathogenesis of the infection and resulting inflammatory response, so that knowledge can drive the development of therapeutic and preventive medications.”
Knowledge about the virus is evolving. A letter to the editor published in The New England Journal of Medicine in mid-March showed the virus that causes COVID-19 may be stable for several hours in aerosols (in this case, droplets from an infected person dispersed in air or gas) and for several hours to days on surfaces. Scientists who participated in the analysis found SARS-CoV-2 was detectable in aerosols for up to three hours, copper up to four hours, cardboard up to 24 hours, and plastic and stainless steel up to two to three days.
Dr. Meyer notes, “A lot of times people will make basic science observations in the research lab, but it takes time for us to figure out how clinically relevant it is. Until we understand more about the granular details of how SARS-CoV-2 passes from person to person, public health dictates that people maintain social distancing, wash hands, and frequently disinfect high-touch surfaces."
In July, 239 scientists in 32 countries wrote an open letter to the WHO outlining evidence that tiny virus droplets people expel when they cough or sneeze can hang in stagnant air for hours, making crowded indoor spaces with poor ventilation risky. The WHO then issued a scientific brief that maintained, among other things, an earlier assertion that the virus is mostly spread through close contact with infected people, but it also called for further research into airborne aerosols and recommended avoiding crowded places, close contact settings, and confined and enclosed places with poor ventilation.
2. Strict measures are critical for slowing the spread of the disease
Public health efforts have been aimed at "flattening the curve." If you map the number of COVID-19 cases over time, the expectation is that it will peak at some point—on a graph this peak would mirror a surge in patients (which could overwhelm hospitals and health care providers). Flattening the curve would mean there would be fewer patients during that period, and hospitals would be better able to manage the demands of patients who are sick with COVID-19 and other illnesses.
Nationally, many places are focused on easing restrictions that have been put in place. White House guidelines for Opening Up America Again, a phased approach to help state and local officials reopen their economies, provides advice on continuing handwashing, wearing face masks, and taking other precautions during the reopening.
Meanwhile, communities have been ramping up contact tracing efforts to locate and support people who have had a potentially high-risk exposure to someone infected with COVID-19.
3. Infection prevention is key
There are many things you can do to protect yourself and the people you interact with. “The best thing you can do at this point is take care of yourself the way you would to prevent yourself from getting the flu,” says Yale Medicine infectious diseases specialist Joseph Vinetz, MD. “You know you can get the flu when people sneeze and cough on you, or when you touch a doorknob. Washing hands—especially before eating and touching your face, and after going to the bathroom—and avoiding other people who have flu-like symptoms are the best strategies at this point.”
Still, studies have shown that a significant portion of people with coronavirus have no symptoms or have symptoms so mild (like loss of smell) they may go undetected. Even those who eventually develop symptoms can transmit the virus to others before showing symptoms. In general, the more people you interact with, the more closely you interact with them, and the longer the interaction, the higher your risk of getting and spreading COVID-19, according to the CDC.
The CDC recommends the following preventive actions:
- Wash hands with soap and water for at least 20 seconds. Dry them thoroughly with an air dryer or clean towel. If soap isn’t available, use a hand sanitizer with at least 60% alcohol.
- Stay home if you’re sick.
- Avoid touching nose, eyes, and mouth. Use a tissue to cover a cough or sneeze, then dispose of it in the trash.
- Use a household wipe or spray to disinfect doorknobs, light switches, desks, keyboards, sinks, toilets, cell phones, and other objects and surfaces that are frequently touched.
- Create a household plan of action in case someone in your house gets sick with COVID-19. You should talk with people who need to be included in your plan, plan ways to care for those who might be at greater risk for serious complications, get to know your neighbors, and make sure you and your family have a plan for caring for a sick person. This includes planning a way to separate a family member who gets sick from those who are healthy, if the need arises.
- Plan visits with friends and family outdoors if possible. If you must visit them indoors, make sure the space can accommodate social distancing, and open doors and windows to make sure the space is well-ventilated.
- If you are going out in public, bring a cloth face covering to wear over the nose and mouth, tissues, and a hand sanitizer with at least 60% alcohol, if possible. Avoid people who are not wearing cloth face coverings. Always wear a face mask in public settings where other social distancing measures are difficult to maintain, especially in areas where there is significant community-based transmission.
The CDC has encouraged organizers of events and gatherings to require staff members to wear cloth face coverings, and individuals to wear them when physical distancing is difficult and where people might raise their voices (shouting, chanting, singing). It has also issued recommendations for people who plan to visit banks, restaurants, gyms, nail salons, libraries, and other locations, or who are traveling overnight.
It is especially important for people to consider their level of risk if they are deciding to go out in public. The CDC advises anyone who is at increased risk for severe illness and anyone who lives with them to limit interactions with people as much as possible, and take the above precautions when they do.
In addition, the CDC is urging everyone to get the flu vaccine. The flu vaccine is especially important this year, since Covid-19 and flu can have similar symptoms, which can complicate diagnosis, and both can result in severe illness and complications. A free online tool called VaccineFinder can help with finding locations that offer the flu vaccine.
4. Experts are working rapidly to find solutions
In the U.S., widely available testing is important in understanding how the disease is transmitted and the true infection and mortality rates. While health providers across the country are using a variety of tests—and still learning about the most accurate approach—two kinds of tests are important to know about: viral tests help diagnose a current infection and antibody tests can tell if you’ve had a previous one (it is not yet known whether COVID-19 antibodies can protect from being infected again or how long protection might last). Health care providers and state and local health departments make determinations about who should be tested.
Meanwhile, scientists are studying the virus closely. “With the new virus in a culture dish, they are looking at the biology and working to make drugs to treat it,” says Dr. Vinetz. There is also a great deal of effort underway to assess drugs in development (and some medications currently available) to determine if they are beneficial for treating patients infected with COVID-19, adds Dr. Martinello.
A number of existing medicines have been suggested as potential investigational therapies for COVID-19. In early May, the FDA issued its first emergency use authorization for a COVID-19 treatment for the investigational antiviral drug remdesivir, allowing use of the drug to treat suspected or laboratory-confirmed COVID-19 in adults and children hospitalized with severe disease. While there is still limited information about the safety and effectiveness of remdesivir when used for COVID-19, preliminary studies have shown that it may shorten recovery time in the hospital from 15 to 11 days.
More recently, the WHO issued new treatment guidelines to make corticosteroids (also known as steroids) a standard of care, but only for patients with “severe and critical” cases of COVID-19. The guidelines were made after analysis of seven clinical trials, published in the Journal of the American Medical Association, showed the drugs reduced the risk of death in hospitalized COVID-19 patients by a third.
5. If you feel ill, here's what you should do
Symptoms of COVID-19 can appear anywhere between 2 to 14 days after exposure.
According to the CDC, symptoms may include:
- Fever or chills
- Shortness of breath or difficulty breathing
- Muscle or body aches
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
This list does not include all possible symptoms. The CDC will continue to update its symptoms list as it learns more about COVID-19.
You should call your medical provider for advice if you experience these symptoms, especially if you have been in close contact with a person known to have COVID-19 or live in an area with ongoing spread of the disease. The CDC has a Coronavirus Self-Checker that may help you determine whether you should seek help.
Most people will have a mild illness and can recover at home without medical care. Seek medical attention immediately if you are at home and experience emergency warning signs, including difficulty breathing, persistent pain or pressure in the chest, new confusion or ability to arouse, or bluish lips or face. This list is not inclusive, so consult your medical provider if you notice other concerning symptoms.
Patients and members of the community can call the Yale Medicine/Yale New Haven Health Call Center at COVID-19 hotline of Yale New Haven Health at 203-688-1700 (toll-free, 833-484-1200) if they have questions.
Be aware of the information and resources that are available to you
Because knowledge about the new virus is evolving rapidly, you can expect information and recommendations to change frequently. Threats like COVID-19 can lead to the circulation of misinformation, so it’s important to trust information only from reputable health organizations and sources such as the CDC and the WHO. “The public health infrastructure in the U.S. is a critical resource for leading the federal, state, and local response,” Dr. Martinello says.
Yale Medicine doctors are advising anyone who has concerns about COVID-19 exposure or symptoms to call their primary care doctor for instructions. Doctors at Yale Medicine and Yale New Haven Health (YNHH) also encourage all patients to sign up for MyChart, a secure online portal that allows patients to manage and receive information about their health, and enables telehealth visits (by phone or video), which is how Yale Medicine specialists currently are delivering most care not related to COVID-19. If you are looking for a testing site, YNHH can help you find one that meets your needs and schedule.
Health officials recognize that the outbreak has been stressful for everyone, and this can have serious impacts on mental health. If you, or someone you care about, are feeling overwhelmed with emotions like sadness, depression, or anxiety, or feel like you want to harm yourself or others, call 911, or the Substance Abuse and Mental Health Administration’s Disaster Distress Helpline: 1-800-985-5990 or text TalkWithUs to 66746. (TTY 1-800-846-8517). You can call the National Domestic Violence Hotline at 1-800-799-7233 (TTY: 1-800-787-3224.)