Anti-SARS-CoV-2 (IgG and IgM)
What is the Symbiotica COVID-19 IgG and IgM Detection by ELISA Antibody test?
The test is designed to detect antibodies (also known as immunoglobulins) against the virus that causes COVID-19.
Antibodies are proteins produced by the immune system in response to an infection and are specific to that particular infection. They are found in the liquid part of blood specimens which is called serum or plasma, depending on the presence of clotting factors. Your sample will be tested for immunoglobulin G (IgG) only or with immunoglobulin M (IgM).
This test detects IgG antibodies that develop in most patients within seven to 10 days after symptoms of COVID-19 begin. IgG antibodies remain in the blood after an infection has passed. These antibodies indicate that you may have had COVID-19 in the recent past and have developed antibodies that may protect you from future infection. It is unknown at this point how much protection antibodies might provide against another infection of COVID-19.
This test also detects IgM antibodies. IgM is usually the first antibody produced by the immune system when a virus attacks. A positive IgM test indicates that you may have been infected and that your immune system has started responding to the virus. When IgM is detected you may still be infected or you may have recently recovered from a COVID-19 infection.
What are the known and potential risks and benefits of the test?
Potential risks include:
Possible discomfort, bruising, infection or other complications that can happen during sample collection. Serious complications are very rare.
Possible incorrect test result (see below for more information).
Potential benefits include:
The results, along with other information, can help you and your health care provider make informed recommendations about your care.
The results of this test may help limit the spread of COVID-19 to your family and others in your community.
Peace of mind.
Why should I get tested?
You should be tested because:
your health care provider believes you may have been exposed to the virus that causes COVID-19 based on your current or previous signs and symptoms (e.g., fever, cough, difficulty breathing);
you live in or have recently traveled to a place where transmission of COVID-19 is known to occur;
you have been in close contact with an individual suspected of or confirmed to have COVID-19; or
you have recovered from COVID-19
Peace of mind.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously called 2019-nCoV) belongs to the family of coronaviruses and, like SARS-CoV, is classified in the genus Betacoronavirus. The new coronavirus originated in China in the city of Wuhan, Hubei province. It caused an infection wave, which has spread rapidly within the country and worldwide. Just a few days after the first report about patients with pneumonia of unclear origin, the causative pathogen was identified as SARS-CoV-2.
SARS-CoV-2 is predominantly transmitted by droplet infection via coughing or sneezing and through close contact with infected patients. Health care personnel and family members are among the high-risk populations. The zoonotic reservoir of the virus appears to be bats.
The incubation time of SARS-CoV is three to seven, maximally 14 days. The symptoms of SARS- CoV-2 infection are fever, coughing, breathing difficulties and fatigue. In most patients the infection manifests with symptoms of a mild febrile illness with irregular lung infiltrates. Some patients, especially elderly or chronically ill patients, develop severe acute respiratory distress syndrome (ARDS). The disease is fatal in around 3% of cases. In February 2020, the disease caused by SARS- CoV-2 was named COVID-19 by the WHO.
Suitable methods for diagnosis of SARS-CoV-2 infections are direct detection of the virus by polymerase chain reaction (PCR) primarily in sample material from the upper (smear) or lower respiratory tract (bronchoalveolar lavage fluid, tracheal secretion, sputum, nasopharyngeal secretion, oropharyngeal secretion, etc) and the detection of antibodies against SARS-CoV-2 in blood. The determination of antibodies enables confirmation of SARS-CoV-2 infection in patients with typical symptoms and in suspected cases without symptoms. It also contributes to monitoring and outbreak control.
Anti-dsDNA (IgG) assay provides semiquantitative in vitro determination of human antibodies of the immunoglobulin class IgG against SARS-CoV-2 to support the diagnosis of SARS-CoV-2 infection and constitutes a supplement to the direct pathogen detection.
What does it mean if I have a positive test result?
If you have a positive test result (antibodies are detected), you may have been infected with the virus that causes COVID-19 at some point in the past.
There is still a chance that the antibodies indicate past infection due to other coronaviruses. These other coronaviruses cause the common cold. There is also a small chance that a positive result is incorrect (false positive).
The presence of IgM (with or without IgG) suggests that the infection happened within the last few weeks. It also suggests that you could still be infectious to others. Having a nasopharyngeal swab test may confirm if you are infectious.
The presence of IgG without IgM suggests that the infection happened weeks to months in the past. It also suggests that you may no longer be infectious. IgG indicates that you may have some immunity to the virus, though you may not. How much it might protect you from getting sick with COVID-19 in the future is unknown.
Your health care provider will work with you to determine how best to care for you based on the test results along with other factors of your medical history, including any previous symptoms, possible exposure to COVID-19 and the location of places you have recently traveled.
What does it mean if I have a negative test result?
A negative test result means that the antibodies to the virus that causes COVID-19 were not found in your sample. However, it is possible for this test to give a negative result that is incorrect (false negative) in some people.
A negative result may occur if you are tested early in your illness and your body hasn’t had time to produce antibodies to infection. This means that you could possibly still have COVID-19 even though the test is negative. If this is the case, your health care provider will consider the test result together with all other aspects of your medical history (such as symptoms, possible exposures and geographical location of places you have recently traveled) in deciding how to care for you.
It is important that you work with your health care provider to help you understand the next steps you should take.