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COVID-19

By

The Manual's Editorial Staff

Last full review/revision Nov 2020| Content last modified Nov 2020
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What is COVID-19?

COVID-19 is a potentially severe viral infection that affects your lungs and airways.

  • It's caused by a new type of coronavirus

  • The virus spreads very easily to other people

  • COVID-19 is now everywhere in the world

  • Some infected people have no symptoms, but others get very sick, and some people die

  • Doctors test swabs from your nose or throat to diagnose COVID-19

  • No medicines cure COVID-19, but some might help people with severe infection, and doctors are always testing additional ones

  • Doctors are also working on a vaccine to prevent COVID-19

What is a pandemic?

COVID-19 is a pandemic. That's an infection that's spreading rapidly in many parts of the world all at once.

What causes COVID-19?

COVID-19 is caused by a new type of coronavirus called SARS-CoV-2. Doctors call it new because it hasn't been around before. It recently changed (mutated) from a type of coronavirus that infects bats.

The virus spreads:

  • Through the air, in droplets that an infected person spreads through a cough, sneeze, singing, or talking

  • Through touching things that infected people have touched and then touching your face

Unlike with many respiratory viruses, you can spread the virus that causes COVID-19 before you have any symptoms. If you don't know you have the virus, you can pass it on and not know it.

Also, COVID-19 spreads from person to person much easier than other respiratory infections like colds or the flu.

What is a coronavirus?

There are hundreds of different coronaviruses that are all related. Most of them infect only animals.

  • Only a few coronaviruses can infect people

  • Some of them cause only colds

  • Three coronaviruses cause very serious illness and can be fatal

Besides COVID-19, the other serious coronavirus infections are called SARS and MERS. Hardly anyone gets those infections anymore.

What are the symptoms of COVID-19?

Many people with COVID-19, particularly children, have almost no symptoms.

If you do get symptoms, you'll likely have:

  • Fever

  • Dry cough

  • Trouble breathing

  • Feeling really weak and tired

You may also have:

  • Runny nose and sore throat

  • Loss of your sense of smell and taste

  • Headaches

  • Stomach problems such as nausea, vomiting, and diarrhea

A bad infection gets deep in your lungs, causing viral pneumonia. That will make you very short of breath. A bad infection can also affect a lot of organs, including your brain, heart, and kidneys.

Is COVID-19 fatal?

You can die from COVID-19. The older you are, the higher your risk of death. Most deaths occur in people over 50 years old. People over 80 are at very high risk. But even children and young adults can die.

You're also at higher risk if you:

  • Have other medical problems such as heart disease, high blood pressure, or diabetes

  • Are a man

  • Are black

How can doctors tell if I have COVID-19?

The most common test uses:

  • A swab taken from your nose or throat

The swab is sent to a lab to look for the virus.

A blood test can look for antibodies your immune system has made to defend against the virus. It takes your body a few weeks to make these antibodies, so this test is not useful when you first get sick. But it can help tell whether you were ever infected.

If you're short of breath, doctors will usually:

  • Do a chest x-ray to look for pneumonia

  • Measure the oxygen level in your blood with a fingertip sensor

How is COVID-19 treated?

If you have a mild or moderate case, you'll:

  • Stay home and not go out or go near other people (isolation)

  • Wear a mask so you don't spread the virus

  • Take acetaminophen or ibuprofen for fever and aches

If you have a severe case, with breathing problems, you'll need to go to the hospital. Doctors will:

  • Give you oxygen

  • Sometimes, give you remdesivir (an antiviral drug) and/or dexamethasone (an anti-inflammatory drug)

  • Sometimes, put you on a ventilator (machine to help you breath)

You may need to be on a ventilator for up to a few weeks.

There are no medicines that are proven to kill the virus, but doctors are trying some that might help.

If you have problems with your kidneys, you may need dialysis.

How can I prevent COVID-19?

The best way to prevent COVID-19 is to avoid being exposed to the virus. People who can spread the virus may not have any symptoms, so you can't tell who has it and who doesn't.

It's important to

  • Keep 6 feet away from people who don't live in your household ("social distancing") and 

  • Wear a mask over your mouth and nose when around people who don't live with you

These actions also help:

  • Wash your hands often with soap and water for at least 20 seconds

  • Use an alcohol-based hand sanitizer

  • Avoid touching your eyes, nose, and mouth with unwashed hands

  • Cover a cough or sneeze with a tissue, then throw the tissue in the trash

  • Use a household disinfectant spray or wipe to clean things people touch a lot, like door handles, phones, remote controls, and countertops

What does it mean to quarantine or isolate?

To help prevent the virus from spreading, certain people should stay away from other people by quarantining or isolating. If you have symptoms of COVID-19, tested positive for COVID-19, or are a "close contact" of someone with COVID-19, you need to isolate or quarantine.

You are a close contact if you

  • Were within 6 feet of an infected person (with or without a mask) for at least 15 minutes, including the 2 days before that person showed symptoms

  • Provided care at home to someone sick with COVID-19

  • Had direct physical contact with the sick person (hugged or kissed them)

  • Shared eating or drinking utensils

  • Were in range of the sick person's respiratory droplets (for example, through a sneeze or cough)

Quarantine is for people who are close contacts. Close contacts may not know if they have the virus or not, because the virus can take 14 days to make you sick or show up in a test. The goal of quarantine is to keep close contacts away from other people until those 14 days are over. If you are a close contact, you need to quarantine for 14 days even if:

  • You don't have symptoms

  • You tested negative—even if you tested negative during the 14 days, you still need to quarantine for the rest of the 14 days

Isolation is for people with COVID-19. If you were a close contact but then you got symptoms or tested positive, you need to isolate. Any days you spent in quarantine don't count for any of the 10 days (at least) you now need to isolate. You should isolate if you:

  • Are sick with COVID-19 symptoms but have not been tested

  • Tested positive (whether or not you have symptoms)

Isolation can generally end 10 days after your symptoms started, as long as you don't have a fever and aren't taking drugs to lower a fever and your symptoms are getting better. If you never had symptoms, you can stop isolating 10 days after the date of your first positive test.

Why do people who might not even have the virus need to quarantine for 14 days, but people who actually have COVID-19 may only need to isolate for 10 days?

  • Before you have symptoms or test positive, you can be contagious (able to spread the virus). It can take up to 14 days after you're exposed to the virus for it to make you sick or show up in a test (called the incubation period). That's why you need to isolate for 14 days, even if at the end it turns out that you never had the virus at all. There was no way to know that you weren't contagious until the 14 days were over.

  • Once you're sick with or test positive for COVID-19, the 14-day period doesn't matter anymore. No matter how many days you were already quarantined (0 to 14 days), once you know you have COVID-19, you start the 10-day isolation clock. Scientists have learned that you most likely are not contagious after 10 days from when you first felt sick or tested positive (unless you still have a fever).

What is contact tracing?

Contact tracing is when health departments look for people who came into contact with someone who has certain infections, including COVID-19. Contact tracers tell you that you may have been exposed to someone with COVID-19, help you get tested, and talk to you about isolating or quarantining. Cooperating with contact tracers helps slow the spread of COVID-19 in the community.

Is there a vaccine for COVID-19?

There's no vaccine yet, though many doctors are working to develop one. Experts think a vaccine will be available some time in 2021.

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