COVID-19 is a contagious disease caused by a new coronavirus, SARS-CoV-2, which emerged in late 2019 and has since spread to more than 200 countries. You need to know how to prevent, diagnose, and treat COVID-19 so you and others do not contract this disease. It can cause mild to severe respiratory illness and even death in some cases.
The virus causing COVID-19 is called SARS-CoV-2 and belongs to the family of coronaviruses. Coronaviruses are known for their spike-like surfaces. SARS-CoV-2 is a new strain of coronavirus that has not previously been identified in humans.
When an infected person coughs, sneezes, or talks, respiratory droplets are released that spread COVID-19. Droplets can land in the mouth or nose of those nearby, or they can be inhaled into the lungs. COVID-19 is also spread by contact with contaminated surfaces or objects, such as door handles, tables, or keyboards, but this is not its most common mode of transmission.
It is important to consider several factors when considering the risk of contracting COVID-19, including the level of community transmission, the type and duration of exposure, and how preventive measures can be taken. In addition to older adults, people with underlying medical conditions, and those with weakened immune systems, some people are more likely to contract COVID-19 or develop severe illness.
The symptoms of COVID-19 vary from person to person, and may appear 2 to 14 days after exposure to the virus. Some people may have no symptoms at all, while others may have mild to moderate symptoms, such as:
Fever or chills
Cough
Shortness of breath or difficulty breathing
Fatigue
Muscle or body aches
Headache
Sore throat
Runny or stuffy nose
Loss of taste or smell
Nausea or vomiting
Diarrhea
Some people may develop more severe symptoms, such as:
Trouble breathing
Persistent chest pain or pressure
Confusion
Inability to wake or stay awake
Bluish lips or face
These are signs of a medical emergency and require immediate attention. Call 911 or your local emergency number if you or someone you know has any of these symptoms.
Testing is the only way to confirm whether you have COVID-19. If you have symptoms of COVID-19 or have been exposed to someone who has COVID-19, contact your health care provider or local health department.
There are different types of tests for COVID-19, such as:
In PCR tests, genetic material of the virus is detected in a sample taken from the nose, throat, or saliva. These tests are very accurate and can provide results within a few hours or days, depending on lab availability.
The antigen test detects specific proteins on the surface of the virus in a sample taken from the nose or throat. These tests are less accurate than molecular tests, but can provide results quickly. If you have symptoms or a high risk of exposure, a negative antigen test may need to be confirmed by a molecular test.
A blood sample can be tested for antibodies, which are proteins that are produced in response to a virus. Antibody tests are not recommended for screening or diagnosing COVID-19. They can tell if you had a previous infection and recovered, but cannot diagnose a current infection.
You should follow the instructions of your health care provider or local health department on how to get tested, where to go, and what to do after your test results. If you have been exposed to someone who has COVID-19, you should also isolate yourself from others until you receive your test results, and quarantine yourself for 14 days.
In certain situations, certain medicines have been approved or authorized for emergency use to treat COVID-19. These include:
In addition to blocking the replication of the virus and reducing the severity or duration of illness, antiviral medicines like nirmatrelvir with ritonavir (Paxlovid), remdesivir (Veklury), and molnupiravir (Lagevrio) are also available. Hospitalized patients and those at high risk of severe illness usually receive these medicines.
These are laboratory-made proteins that can bind to viruses and prevent them from entering the cells, such as bamlanivimab and etesevimab, casirivimab and imdevimab, and sotrovimab. Infusions or injections of these medicines are given to people at high risk of severe illness or hospitalization who have mild to moderate symptoms.
Patients with severe or life-threatening COVID-19 can receive convalescent plasma, a liquid blood component containing antibodies from people who have recovered from COVID-19.
A corticosteroid, such as dexamethasone, is an anti-inflammatory drug that can reduce the risk of death or mechanical ventilation in people with severe COVID-19 and low oxygen levels.
Treatments such as these are not widely available and may have side effects or interactions with other medicines. They should only be used under the supervision of a health care provider and as part of a clinical trial.
In mild or moderate cases of COVID-19, you can manage your symptoms at home by:
Resting and drinking plenty of fluids
Taking over-the-counter medicines, such as acetaminophen or ibuprofen, to reduce fever and pain
Using a humidifier or a warm shower to ease cough and sore throat
Monitoring your oxygen saturation with a pulse oximeter, if available
Seeking medical attention if your symptoms worsen or you have trouble breathing
The best way to prevent COVID-19 is to get vaccinated. Vaccines are safe and effective in preventing severe illness, hospitalization, and death from COVID-19. They can also reduce the risk of infection and transmission. There are a number of COVID-19 vaccines available, including:
There are two types of mRNA vaccines available, Pfizer-BioNTech and Moderna, which use messenger RNA to teach the body how to fight the virus. These vaccines require two doses, given three to four weeks apart, and offer more than 90% protection against COVID-19.
AstraZeneca and Johnson & Johnson use a virus to deliver genes that code for proteins of the Coronavirus. These vaccines require one or two doses, depending on the brand, and offer more than 70% protection against COVID-19.
COVID-19 is prevented by protein subunit vaccines, such as Novavax, which use purified pieces of the coronavirus protein to trigger an immune response.
Your health care provider or local health authority should recommend which vaccine to get, when to get it, and whether you need a booster dose as soon as possible. A number of preventive measures should also be followed, including:
Avoiding close contact with people who are sick or have symptoms of COVID-19
Wearing a mask or a face covering in public places, especially where physical distancing is not possible or where there is a high level of transmission
Practicing good hand hygiene by washing your hands often with soap and water for at least 20 seconds, or using an alcohol-based hand sanitizer if soap and water are not available
Maintaining physical distance of at least 6 feet (2 meters) from others who are not from your household
Improving indoor ventilation by opening windows and doors, using fans or air purifiers, or choosing outdoor settings when possible
Regularly cleaning and disinfecting high-touch surfaces, such as doorknobs, countertops, keyboards, and phones
