How To Read Covid Test Result: A Comprehensive Guide

on July 26th, 2023
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in Health Information and Tips

If you want to travel abroad, consider testing for COVID to avoid surprises. The availability of home-test kits makes it possible to confirm if you have an active infection at your convenience.

Even so, the test kits’ instructions may offer little information to help you make informed choices about your health. If you test a day after exposure to an infected person, the results might mislead you that you’re okay.

A test result might return a false positive or false negative depending on the test kit’s timing, method applied, and quality. The probability of false COVID results highlights the importance of consulting a healthcare provider for an accurate interpretation.

Consider visiting a trusted urgent care center to improve the accuracy levels and reliability of your COVID-19 test.

Types of COVID-19 Tests: Understanding the Differences

People with COVID display many symptoms ranging from mild to severe illness. You may develop symptoms 2-14 days after exposure.

Many people develop mild to severe symptoms, including:

  • Headache
  • Muscle or body aches
  • Diarrhea
  • Sore throat
  • Congestion
  • Vomiting or Nausea
  • Difficulty in breathing or shortness of breath
  • Fever or Chills
  • Runny nose
  • Loss of smell and taste

The above list of COVID symptoms is not exhaustive and may change depending on COVID variants and vaccination status. 

If you’re experiencing any of the above symptoms, consider getting tested.

Note: You can confuse a COVID infection with flu because they have similar symptoms. Although COVID and flu are both respiratory conditions, they are caused by different viruses. More importantly, many testing locations provide PCR tests that tell if you have COVID or flu.

Different types of tests can detect COVID-19. For instance, molecular and antigen tests are applied to discover a current infection. On the other hand, an antigen test investigates if you’ve had a previous COVID infection.

Here’s a look at different types of COVID-19 tests:

Molecular Test for COVID-19

The Molecule is called nucleic acid amplification test(NAAT) or Reverse Transcription Polymerase Chain Reaction Test (RT-PCR).

The molecular test checks for a virus if you’re currently infected. The PCR tests analyze a specimen from the upper respiratory tract to determine if there’s genetic material(ribonucleic acid or RNA) of SARS-CoV-2, the virus responsible for COVID-19.

A medical practitioner applies the PCR technology to amplify tiny bits of RNA found in specimens into DNA — the process continues until SARS-CoV-2, if present, is located. The molecular test has been the gold standard for testing COVID since it was approved for use in 2020.

Here’s how the test is done.

A healthcare provider collects a sample by inserting a long nasal swab into your nostril and taking fluid at the back of your nose. Alternatively, a health professional may use anterior nares swabs, or mid-turbinate swabs, which are shorter.

Additionally, the doctor may ask you to spit in a tube to produce a saliva sample.

The turn-around for molecular tests varies— you may receive the results in minutes if done onsite. However, getting results may take 1-3 days if the sample is taken to an external lab.

Accuracy of Molecular Tests

According to a National Institute of Health study, 96% of molecular tests diagnosed COVID-19 correctly. The molecular test is, therefore, the most preferred method of detecting the SARS-CoV-2 virus.

In addition, the results of a molecular test are sufficient to detect a COVID infection if you already have the symptoms. 

You may have a false negative because of an error during collection, processing, or transportation.

Timing also plays a crucial role; if a mistake occurs, it can also lead to a false negative. 

Here are a few instances that can lead to a false negative:

  • Testing Too Late: The genetic material of a virus begins to decline in the upper respiratory tract after one week of infection. With that in mind, getting a false negative is possible if you test too late after the symptoms occur. 
  • Testing too Early: It takes up to 5 days after exposure to the virus before genetic material builds enough levels to be detected. Therefore, trying too early could give you a false negative.

Antigen Test For COVID-19

Similar to a molecular test, an antigen test detects if you have an active COVID-19 infection. The test detects nucleocapsid protein antigen in the SARS-COV-2 virus responsible for COVID-19.

Antigen tests are rapid tests that produce results within 15-30 minutes. A positive outcome of antigen tests is considered accurate and reliable if instructions are followed well. Even so, an antigen test is less likely to detect COVID than molecular tests.

An antigen test is less sensitive than a molecular test making it highly likely to receive a false negative. Due to the lower sensitivity of antigen tests, it is recommended to use it in a community with a high prevalence rate or on a patient who’s already displaying symptoms. 

The antigen may also return a false-negative if you test too soon after contracting the virus. Most patients who take antigen tests must undergo a PCR test as a confirmation.

Alternatively, individuals with symptoms may use two antigen tests to confirm their COVID status. If you don’t have symptoms, you need 3 antigen tests done 48 hours apart to prove you don’t have COVID.

Here’s how the test is done:

A healthcare professional inserts a long nasal swab to collect a fluid sample. The sample is then inserted in the test kit to produce results within minutes. The specimen may be sent to a lab for analysis in other instances.

Self-Testing At Home

You can use a self-test for COVID anywhere, which gives rapid results. The role of a self-test is to detect a current COVID result— also referred to as ‘’home test’’, ‘’at home test’’, or ‘’over-the-counter test’’.

A self-test is an antigen test that gives results in 10-15 minutes. A self-test differs from PCR administered at a health facility or a self-collected sample taken to a lab for analysis. 

The most significant benefit of self-test is convenience and speed; even so, it has low accuracy levels compared to a PCR test, which means you’re likely to get false results. According to FDA guidelines, consider getting a second self-test after 48 hours if you get a negative outcome. 

Lastly, take a third self-test after 48 hours if it returns negative and you don’t have symptoms. A self-test is likely to detect the virus; alternatively, you can go to a health center for a PCR  test instead of repeating a self-test at home.

How to Use a Self-Test at Home

First, read the manufacturer’s instructions before using the test kit.

Wash your hands thoroughly before collecting the nasal sample, and repeat the procedure once done.

Remember to check the expiry date— if it is expired, discard it to avoid getting a misleading result.

When to Take At- An home COVID-19 Test

If you have COVID-19 symptoms, test immediately. If it turns negative, repeat the procedure 2 times 48 hours apart. Alternatively, visit an urgent care center for a confirmation test or investigation if you have another illness.

If you were exposed to someone with COVID, take the test 5 days after five days after your exposure. Testing is also helpful even if you don’t have symptoms or recent exposure to the SARS-CoV-2 virus. 

For example, if you’re looking forward to traveling or attending an event. Test as close as possible to your day of travel or event to make an informed choice about your health.

COVID Antibody Test

A COVID antibody test, also known as a serology test, is done after full recovery. A health care professional draws blood by pricking your finger or directly from hand veins. The sample is then taken to a lab to determine if you have antibodies against the SARS-Cov-2 virus.

Once you become infected, the immune system develops COVID antibodies to fight and flush the virus from your system. If the test returns a positive result, you have been infected with a COVID virus or developed antibodies after vaccination.

A positive COVID antibody test may also mean you have developed immunity. It’s important to understand that antibodies cannot prevent you from being infected; however, it prevents you from being severely ill.

The timing of an antibody test affects its accuracy levels. If you test too early after infection, when the immune system is still building up, the test may not detect antibodies. Ideally, you should perform the antibody test 2-3 weeks after your symptoms appear.

You can get an antibody test the same day in some health centers. If the sample is sent to a different lab for further analysis, expect the results in 1-3 days.

How to Choose a COVID-19 Test

Here are important considerations when choosing a COVID-19 test:

  • You can use either a molecular or an antigen test if you’ve not had COVID or haven’t obtained a positive test in the last 90 days.
  • If you’ve tested positive in the last 30 days or less and are displaying symptoms use an antigen test and repeat if showing signs.
  • Testing is not recommended to detect an infection if you’ve tested positive in the last 30 days or less and don’t have symptoms.
  • If your positive test was in the last 31-90 days and you have symptoms, use an antigen test and repeat if a negative outcome occurs.
  • If you don’t have symptoms and your positive test was in the last 31-90 days, use an antigen test and repeat if necessary.

After you get a positive test, you may continue getting a positive result for some time. Some PCR tests continue showing a positive outcome for up to 90 days. A re-infection may also occur within 90 days, making it challenging to tell if it’s a new infection.

Always consult a healthcare provider to get the results right when in doubt.

Understanding Your COVID-19 Risk

Anyone can get a COVID-19 infection, which can cause mild to severe symptoms. While some people develop no symptoms, some become critically ill, necessitating breathing machines. 

Here are the risk factors that increase the likelihood of getting a severe form of COVID:

  • Older Adults: Older adults—those aged 50 years and above— are more likely to get a severe form of COVID than younger ones. The risks become lower with age, so you’ll likely require hospitalization, a ventilator for breathing, and intensive care. Most deaths occur in those aged 65 years and above. In addition, the risk increases if you’re not vaccinated, have a disability, weakened immune system, or other medical conditions.
  • Pregnant or a Recently Pregnant Woman: During pregnancy, the body undergoes several changes that make it easy to get very ill from respiratory illness. If a pregnant woman gets COVID, they will likely get complications that may affect the developing baby, leading to preterm or stillborn infants. The risk may also increase if you’re above 25 years, have underlying medical conditions, or live in communities with low vaccination levels.
  • People With Medical Conditions: People with medical conditions such as cancer, HIV infection, Diabetes, Dementia, and heart conditions are at high risk of becoming severely ill. For instance, people with heart conditions such as heart failure, coronary artery disease, or congenital heart disease are highly likely to get a complicated form of COVID.
  • People With a Weakened Immune System: People with a compromised immune system are also likely to get sick and for longer with COVID. A weak immune system occurs due to medical conditions or undergoing treatment that suppresses your immune system. A weak immune system may occur because of organ transplant, bone-marrow transplant, or prolonged use of prednisone.

Understanding your risk of COVID and those around you helps you make informed decisions about your safety and health.

Reading Positive COVID-19 Test Results: What it Means

A positive result means you are infected with the SARS-CoV-2 virus, which causes COVID. You should therefore take appropriate steps to take care of yourself.

Here are a few steps to take care of yourself and avoid spreading the virus to others:

  • Isolate for at least five days.
  • Wear a high-quality mask or respirator to protect those around you from getting infected.
  • Inform people you’ve recently had contact with that they’ve been exposed.
  • Monitor your symptoms—if you develop emergency symptoms like difficulty breathing, seek emergency help immediately.
  • Contact a nearby urgent care center about your treatment options
  • Stay hydrated
  • Get enough rest

Although rare, you can get a false positive which implies you’re infected when you’re not. 

Some possible reasons for getting a false positive include a contaminated test kit and not following instructions. It’s also advisable to test when you’re already experiencing symptoms. More importantly, buy an FDA-approved home-test kit to ensure a reliable result.

Interpreting Negative COVID-19 Test Results: Important Considerations

A negative COVID result means the test didn’t detect the virus but doesn’t rule out an infection. If you have symptoms, you could still have the virus but haven’t developed to detectable levels. It is also possible to have another viral infection or illness; you should consider getting tested.

If you do not have symptoms but were exposed to the COVID-19 virus, take the following steps:

  • Start wearing a high-quality mask or respirator, e.g. (N95), from day one of your last exposure
  • Avoid going to places where you’re unable to wear a mask 
  • Take extra precautions when around people who are more likely to get a severe COVID-19 infection
  • Watch out for COVID symptoms such as cough, fever, shortness of breath, fatigue, chills, and headaches. If you develop these symptoms, isolate immediately, get tested, and stay home until you know the results.
  • Continue observing the precautions for 10 days— you can develop COVID up to 10 days after exposure.
  • Get tested on day 6— it’s advisable to get tested after 5 five full days of your last exposure.
  • If you test negative, continue taking full precautions until 10 days are over. 

If you do not have symptoms and haven’t been exposed to the virus, you may resume normal activities, including travel plans. 

Indeterminate or Invalid Results: What to Do Next

A result returns Invalid or Indeterminate if the PCR or lab-based test cannot determine if your status is negative or positive. 

You could get an invalid test for two reasons:

  • The swab did not collect enough respiratory fluid to determine the presence or absence of the SARS-CoV-2 virus.
  • The test could not be validated.

As a result, the sample collection exercise should be repeated to determine whether you do or do not have COVID.

Try Newport Urgent Care Center COVID-19 Testing Services

If you test positive for COVID on arrival to a foreign country, you will be forced to self-isolate. The surprise result can disrupt a planned business meeting or family holiday and increase your cost of travel.

It’s, therefore, essential to interpret COVID-19 results correctly to avoid disappointments and unplanned expenses.

Newport Urgent Care & Occupational Medicine has a well-equipped lab and board-certified physicians ready to assist you with your COVID test.

Contact us online or call us at 949.832.6347 to book your appointment.