What is coronavirus?
Coronaviruses are a family of viruses that can cause respiratory illness in humans. They get their name, “corona,” from the many crown-like spikes on the surface of the virus. Severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and the common cold are examples of coronaviruses that cause illness in humans.
The new strain of coronavirus, COVID-19, was first reported in Wuhan, China in December 2019. The virus has since spread to all continents (except Antarctica).
How many people are infected with COVID-19?
The number of people infected changes daily. Organizations that collect this information, including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), are gathering information and continuously learning more about this outbreak. As of this writing (05/11/2021), more than 159,000,000 people in the world have been infected. Over 3,300,000 people have died. Some 192 countries and territories on all continents (except Antarctica) have now reported cases of COVID-19. The U.S. has the highest number of cases, with more than 32,000,000 people infected and over 580,000 deaths. India has nearly 23,000,000 cases and 250,000 deaths. Brazil has more than 15,200,000 cases and 420,000 deaths. France has over 5,800,000 cases; Turkey has over 5,000,000 cases; Russia and England have over 4,400,000 cases; Italy has more than 4,100,000; Spain and Germany have over 3,500,000 cases; Argentina and Columbia have more than 3,000,000 cases; Poland and Iran have over 2,600,000 cases and Mexico has over 2,300,000 cases. For the latest statistics, see the World Health Organization's situation reports and Johns Hopkins Coronavirus Resource Center map references at end of article.
How does the new coronavirus (COVID-19) spread from person to person?
COVID-19 is likely spread:
- When the virus travels in respiratory droplets when an infected person coughs, sneezes, talks, sings or breathes near you (within six feet). This is thought to be the main way COVID-19 is spread.
- When the virus travels in small respiratory droplets that linger in the air for minutes to hours from an infected person who is more than six feet away or has since left the space. This method of spread is more likely to occur in enclosed spaces with poor ventilation.
- From close contact (touching, shaking hands) with an infected person.
- By touching surfaces that the virus has landed on, then touching your eyes, mouth, or nose before washing your hands. (Not thought to spread easily by this method.)
COVID-19 enters your body through your mouth, nose or eyes (directly from the airborne droplets or from transfer of the virus from your hands to your face). The virus travels to the back of your nasal passages and mucous membrane in the back of your throat. It attaches to cells there, begins to multiply and moves into lung tissue. From there, the virus can spread to other body tissues.
Governments, health agencies, researchers and healthcare providers are all working together to develop policies and procedures to limit the spread of this virus both globally and from individual to individual.
How long is a person infected with COVID-19 considered contagious?
Researchers are still learning about COVID-19. What IS known is that people infected with COVID-19 can spread the virus to others before experiencing symptoms themselves (while people are still “asymptomatic”). Once you do have symptoms, the CDC says you are no longer contagious 10 days after your symptoms began.
Until everything about COVID-19 is fully understood, the best advice from healthcare providers to remain safe is to:
- Stay six feet away from others whenever possible.
- Wear a cloth mask that covers your mouth and nose when around others.
- Wash your hands often. If soap is not available, use a hand sanitizer that contains at least 60% alcohol.
- Avoid crowded indoor spaces. Bring in outdoor air as much as possible.
- Stay self-isolated at home if you are feeling ill with symptoms that could be COVID-19 or have a positive test for COVID-19.
- Clean and disinfect frequently touched surfaces.
How soon after becoming infected with COVID-19 will I develop symptoms?
This so-called “incubation period,” the time between becoming infected and showing symptoms, can range from two to 14 days. The average time before experiencing symptoms is five days. Symptoms can range in severity from very mild to severe. In about 80% of patients, COVID-19 causes only mild symptoms.
Who is most at risk for getting COVID-19?
Persons at greatest risk of contracting COVID-19 are:
- People who live in or have recently traveled to any area with ongoing active spread.
- People who have had close contact with a person who has a laboratory-confirmed or a suspected case of the COVID-19 virus. Close contact is defined as being within six feet of an infected person for a cumulative total of 15 minutes or more over a 24-hour period.
- People over age 60 who have pre-existing medical conditions or a weakened immune system.
Have certain ethnic groups been harder hit by COVID-19?
Yes. Many researchers have been analyzing data across the country and in some large cities, looking at number of confirmed cases and deaths based on race and ethnicity and related factors. What they found is that African Americans and the Latino-Hispanic populations have disproportionate higher rates of hospitalizations and deaths due to COVID-19.
There are several reasons why researchers suspect these populations are more affected. They believe these ethnic groups tend to:
- Live in more crowded housing situations -- living in densely populated areas and in multi-generational households -- making social distancing practices difficult.
- Work in consumer-facing service industries and are more likely to use public transportation to get to work, putting them at risk for increased exposure to COVID-19.
- Be at increased risk of severe illness if they get COVID-19 because of higher rates of existing medical conditions, such as high blood pressure, diabetes, obesity, asthma, and heart, liver and kidney diseases.
- Be more likely to be uninsured or lack a consistent care source, which limits access to COVID-19 testing and treatment services.
Researchers are still studying other factors that may make ethnic groups more susceptible to negative COVID-19 outcomes, including genetics and possible differences in lung tissue as well as socioeconomic status and the social environment and systems.
If I recover from a case of COVID-19, can I be infected again?
The U.S. Centers for Disease Control says that "the immune response to COVID-19 is not yet understood." Because this is a new strain of coronavirus, scientists are still collecting information and research on the virus so it's still too early to know if you can get it a second time if you've had it once.
In a related theme, scientists are seeing a subset of patients who have COVID-19 and have symptoms that continue off and on for weeks and even months. These patients are called coronavirus long haulers. Scientists continue to follow these patients.
Where do coronaviruses come from?
Coronaviruses are often found in bats, cats and camels. The viruses live in but do not infect the animals. Sometimes these viruses then spread to different animal species. The viruses may change (mutate) as they transfer to other species. Eventually, the virus can jump from animal species and begins to infect humans. In the case of COVID-19, the first people infected in Wuhan, China are thought to have contracted the virus at a food market that sold meat, fish and live animals – but they are still investigating. Although researchers don’t know exactly how people were infected, they already have evidence that the virus can be spread directly from person to person through close contact.
Symptoms and Causes
What are the symptoms of the novel coronavirus (COVID-19) infection?
The CDC says you may have coronavirus if you have these symptoms or combination of symptoms:
- 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.
Additional symptoms are possible.
Symptoms may appear between two and 14 days after exposure to the virus. Children have similar, but usually milder, symptoms than adults. Older adults and people who have severe underlying medical conditions like heart or lung disease or diabetes are at higher risk of more serious complication from COVID-19.
Call 911 and get immediate medical attention if you have these warning signs:
- Trouble breathing.
- Persistent pain or pressure in your chest.
- New confusion.
- Inability to arouse (wake up from sleep).
- Bluish lips or face.
This list does not include all possible symptoms. Contact your healthcare provider if you are concerned you may coronavirus, have other symptoms or have any severe symptoms.
Diagnosis and Tests
How is coronavirus diagnosed?
COVID-19 is diagnosed with a laboratory test. Your healthcare provider may collect a sample of your saliva or swab your nose or throat to send for testing.
When should I be tested for the coronavirus (COVID-19)?
Call your healthcare provider if you:
- Feel sick with fever, cough or have difficulty breathing.
- Have been in close contact with a person known or suspected to have COVID-19.
Your healthcare provider will ask you questions about your symptoms. Your healthcare provider will tell you if you need to be tested for the novel coronavirus, COVID-19 and where to go to be tested.
If I have a positive test for coronavirus, how long should I self-isolate?
According to current CDC recommendations, you should self-isolate until you've met all three of the following criteria:
- It's been 10 days since your symptoms first appeared.
- You've not had a fever for 24 hours and you've not used fever-lowing medications during this time.
- Your COVID-19 symptoms have improved.
While at home, ideally self-isolate within separate room of your home if possible to limit interaction with other family members. If you can’t stay 100% isolated in a separate room, stay six feet away from others and wear a cloth mask, wash your hands often/family members wash hands often, and frequently disinfect commonly touched surfaces and shared areas.
You don't need to be retested to be around others outside your home. However, since everyone and every case is unique, follow your healthcare provider's recommendations for testing.
If you have a weakened immune system or have had a severe case of COVID-19, the CDC's criteria do not apply to you. You may need to stay home for up to 20 days after your symptoms first appeared. Talk with your healthcare provider about your situation.
How long do I need to isolate myself if I’ve been around a person with COVID-19?
According to the CDC, if you’ve been in close contact with a person who has COVID-19, your safest strategy is to stay home for 14 days after you’ve last seen this person.
Recently, the CDC updated its guidance. Alternatives to the 14-day quarantine are:
- End your quarantine after 10 days without a test if you've had no symptoms at any time over these 10 days.
- End your quarantine after seven days if you've had no symptoms at any time over these seven days and have tested negative for COVID-19. Your COVID-19 test should be obtained no earlier than day 5 of your quarantine. If you get a negative test result back before day 7, stay isolated for the full seven days. If you don't get results back by day 7, continue to quarantine until you do, up to day 10.
Is it possible to test negative for COVID-19 and still be infected with the virus?
Yes. This is possible. There are several reasons for “false negative” test results -- meaning you really DO have COVID-19 although the test result says you don’t.
Reasons for a false negative COVID-19 test result include:
- You were tested too early in the course of illness. The virus hasn’t multiplied in your body to the level that it could be detected by the test.
- A good specimen was not obtained. The healthcare personnel may not have swabbed deeply enough in the nasal cavity to collect a good sample. There could also be handling errors and transportation errors, as the sample must be transported to a lab to be tested.
- The COVID-19 test itself was not sensitive or specific enough to detect COVID-19. “Sensitivity” refers to the ability of the test to detect the smallest amount of virus. “Specificity” refers to the ability of the test to detect only the COVID-19 virus and not other similar viruses. Many different commercial and hospital laboratories have developed tests for COVID-19. All must meet standards, but no test is 100% sensitive and 100% specific for COVID-19. This is why there is always a possibility of “false negative” and “false positive” tests.
If you think you might have COVID-19 even if your test is negative, it’s best to follow the current CDC recommendation. Stay home for 10 days if you think you are sick. Stay six feet away from others (“social distancing”) and wear a cloth mask. Contact your healthcare provider if your symptoms worsen. Contact your healthcare provider when your symptoms improve – don’t decide on your own if it’s safe for you to be around others.
Management and Treatment
What medications are currently approved to treat COVID-19?
Currently, only one drug has received Food and Drug Administration (FDA) approval. Remdesivir (Veklury®) is approved to treat hospitalized patients with COVID-19 infection.
What treatments do people receive if they have COVID-19?
One authoritative organization – The National Institutes of Health COVID-19 Treatment Guidelines Panel – recommends the following treatments based on the severity of COVID-19.
If you’re not in the hospital or don’t need supplemental oxygen:
- No specific antiviral or immunotherapy is recommended.
If you’re in the hospital:
- You may be given IV remdesivir with or without the oral (by mouth) corticosteroid dexamethasone (or other steroid) or dexamethasone alone if remdesivir can’t be used.
- Depending on the severity of your COVID infection, you may need:
- Supplemental oxygen (given through tubing inserted into your nostrils).
- Mechanical ventilation (receive oxygen through a tube inserted down your trachea). You are given medications to keep you comfortable and sleepy as long as you’re receiving oxygen through a ventilator.
- Extracorporeal membrane oxygenation (ECMO). You continue to receive treatment while a machine pumps your blood outside your body. It takes over the function of your body’s lungs and heart.
The National Institutes of Health COVID-19 Treatment Guidelines Panel recommends AGAINST the following treatments:
- Chloroquine or hydroxychloroquine with or without azithromycin for the treatment of hospitalized and non-hospitalized patients (except in a clinical trial).
- Lopinavir/ritonavir or other HIV protease inhibitors (except in a clinical trial).
- Ivermectin (except in a clinical trial).
What other medications have been given FDA emergency use approval for treating COVID-19?
The FDA granted emergency use authorization (EUA) for the investigational monoclonal antibody bamlanivimab for the treatment of mild-to-moderate COVID-19 infection in adults and children aged 12 and older who weigh 88 pounds (40 kg) who are not in the hospital. Patients must be at high risk of worsening to severe status and/or need hospitalization. The drug is administered through your vein (IV).
EUA status has also been granted for the combination of two monoclonal antibody drugs -- casirivimab and imdevimab -- in adults and children aged 12 and older who weigh 88 pounds (40kg). The combination is recommended for use in patients with mild-to-moderate COVID-19 who are at high risk of worsening to severe status.
The FDA has also granted EUA for convalescent plasma to treat COVID-19. This is blood donated from people who have a confirmed case of COVID-19 and have recovered.
What vaccines are in use or in late-stage development to prevent COVID-19?
The Food and Drug Administration has granted Emergency Use Authorization for three coronavirus vaccines. The companies manufacturing the vaccines are Pfizer/BioNTech, Moderna/NIH and Johnson & Johnson. Initial doses of the Pfizer and Moderna vaccines were distributed in the United States (and worldwide) beginning in December 2020. In April of 2021, the CDC and Food and Drug Administration recommended a pause in the use of the Johnson & Johnson vaccine. Six women in the U.S. developed blood clots after receiving this company's vaccine. The agencies want to investigate any possible link between the vaccine and clots and determine if indications of who should receive this vaccine need to be changed. The 10-day pause was lifted in late April and distribution of the vaccine resumed without restrictions.
The Pfizer vaccine is administered as two doses, 21 days apart and is authorized for use in those age 12 and older. The Moderna vaccine is administered as two doses, 28 days apart and is authorized for use in those age 18 and older. Both vaccines have shown similar efficacy levels of near 95%.
Johnson & Johnson’s vaccine is a single dose vaccine authorized for use in individuals 18 years of age and older. Results of a 44,000-person global clinical trial showed the vaccine to be 67% effective against moderate-to-severe COVID-19 at 14 days after being vaccinated and 66% effective at 28 days after vaccination. Against severe COVID-19, the vaccine was found to be 77% effective at 14 days after vaccination and 85% at 28 days after vaccination.
More than 50 vaccines continued to being studied to prevent COVID-19. They are now in late-stage (phase three) development and enrolling participants in the United States. Information on some of these vaccines includes:
- AstraZeneca and the University of Oxford are testing their two-dose vaccine in 30,000 trial enrollees. They are reporting that their vaccine is up to 90% effective.
- Novavax has a two-dose vaccine being tested in a trial enrolling 40,000 people.
For more information on the nearly 4,000 clinical trials of medications and vaccines under development anywhere in the world, visit clinicaltrials.gov.
If I’ve tested positive for COVID-19 and do not need hospitalization, what can I do to best manage my symptoms at home?
If you have mild COVID-19 symptoms, you will likely need to manage your health at home. Follow these tips:
- If you have a fever, drink plenty of fluids (water is best), get lots of rest, take acetaminophen (Tylenol®).
- If you have a cough, lie on your side or sit up (don’t lie on your back). Add a teaspoon of honey to your hot tea or hot water (don’t give honey to children under one year old). Gargle with salt water. Call your healthcare provider or pharmacist for advice about over-the-counter, comfort care product, like cough suppressants, cough drops/lozenges. Have a friend or family member pick up any needed medicines. You must stay at home.
- If you are anxious about your breathing, try to relax. Take slow deep breaths in through your nose and slowly release through pursed lips (like you’re are slowly blowing out a candle). If you are having trouble breathing, call 911.
If you have a mild case of COVID-19, you should start to feel better in a few days to a week. If you think your symptoms are getting worse, call your healthcare provider.
How can I prevent getting the novel coronavirus (COVID-19)?
Right now, the best defense to prevent getting COVID-19 is to follow some of the same steps you would take to prevent getting other viruses, such as the common cold or the flu.
- Wash your hands for at least 20 seconds— especially before eating and preparing food, after using the bathroom, after wiping your nose, and after coming in contact with someone who has a cold.
- Avoid touching your eyes, nose and mouth to prevent the spread of viruses from your hands.
- Cover your mouth and nose with a tissue when sneezing and coughing or sneeze and cough into your sleeve. Throw the tissue in the trash. Wash your hands afterward. Never cough or sneeze into your hands!
- Avoid close contact (within six feet) with those who have coughs, colds or are sick. Stay home if you are sick.
- If you are prone to sickness or have a weakened immune system, stay away from large crowds of people. Follow the directions of your healthcare authorities especially during outbreaks.
- Clean frequently used surfaces (such as doorknobs and counter tops) with a virus-killing disinfectant.
- Use hand sanitizers that contain at least 60% alcohol if soap and water are not available.
- Greet people with a friendly gesture instead of shaking hands.
- Get enough sleep, eat a healthy diet, drink plenty of liquids and exercise if you are able. These steps will strengthen your immune system and enable you to fight off infections easier.
Should I wear a face mask?
The CDC recommends wearing a cloth face coverings in public, especially in places where it’s hard to maintain at least six feet of distance between yourself and another person. Face masks protect both you and the people around you. Cloth face masks are being recommended because we now know individuals with COVID-19 could have mild or no symptoms, while still spreading the virus to others.
The cloth face coverings recommended by the CDC are not surgical masks or N-95 respirators, which should be reserved for healthcare workers and first responders.