What are the types of coronavirus tests?
There are two basic types of tests for COVID-19.
Viral or diagnostic test: A viral test can tell you if you are currently infected with the coronavirus that causes COVID-19. This is the test you will receive if your doctor refers you for a COVID-19 test based on your symptoms and other factors.
Early in the pandemic, researchers at Johns Hopkins Medicine developed a screening test that we use, along with other types of viral detection tests, to check for the virus.
Antibody test: An antibody test can show if you were previously exposed to or infected with the virus that causes COVID-19, and if your body has created antibodies in an attempt to defend itself. It takes at least 12 days after exposure for your body to make enough antibodies to show up on a test.
This test helps scientists gather data about how the immune system fights off COVID-19 in recovered patients. We do not yet know if a person with a positive antibody test is protected from getting re-infected with the virus or, if so, how long that protection might last.
Who should get a coronavirus test?
The answer varies based on many factors including a person’s symptoms, exposure history and underlying risk factors for severe disease.
People Who Have COVID-19 Symptoms:
Everyone with coronavirus symptoms should self-isolate and contact their medical provider or a local center to schedule a test. Many people have mild symptoms, and it will become increasingly difficult to tell whether symptoms are due to COVID-19 once other respiratory viruses such as influenza start to circulate in the fall and winter months. Tests can be helpful to find out if symptoms are due to COVID-19 so you can take precautions to avoid passing the infection to others. Test results can also help to guide your medical care whether you have COVID-19 or another type of respiratory virus.
Talk to your health care provider to find out what he or she recommends. Remember, unless you have life-threatening circumstances that require calling 911 or going to an emergency department, stay home and call your doctor’s office to discuss your symptoms before going to a health care facility or testing site. This helps prevent the spread of the virus.
It’s also important to know that the availability of testing varies by state and local health department. Johns Hopkins Medicine provides tests with a doctor’s referral and, in some cases, for Maryland and Washington, D.C., residents who do not have a referral.
In areas where testing remains in short supply, according to the U.S. Centers for Disease Control and Prevention (CDC), these groups should be given priority to be tested for COVID-19:
- Hospitalized patients with COVID-19 symptoms.
- People who work in health care facilities and group residences such as nursing homes.
- First responders (emergency medicine technicians, police officers, firefighters and others) who have COVID-19 symptoms.
- People with COVID-19 symptoms who live in long-term care facilities or other group living settings, including prisons and shelters.
The next level of priority goes to those who:
- Have COVID-19 symptoms such as cough, fever or chills, shortness of breath or difficulty breathing, muscle or body aches, sore throat, new loss of taste or smell, diarrhea, headache, new fatigue, nausea or vomiting, or congestion or runny nose.
- Are recommended for testing by their doctor or local health department for public health monitoring or other reasons.