COVID-19 Testing Update 4-29-20: PCNM Does Antibody Testing

Updated: Mar 6, 2021

Brief Update

Approximately < 1.75% of the US population has been tested.

5.6% of tests were POSITIVE (+)

Total Positive Test Results in the US = 1,030,487


TOTAL US DEATHS = 57,505

TOTAL DEATHS IN THE WORLD = 226,173


In Oregon, ~ 10,500 tests are processed a week.

2,446 cases as of APRIL 29TH

101 Total Deaths


 

In March, the FDA began allowing developers to market serological tests as long as they follow guidelines. One reason is for treatment with plasma therapy and another reason is to learn more about the virus and its relationship to us. There is no FDA-approved serological test. To date, Cellex is the only serological test authorized under emergency use (EUA, emergency use authorization). You can find a list of EUA tests here.


When can I expect my test results?

You can expect results for the antibody test in a few days and around a week for NAAT/RT-PCR.


Two kinds of tests are available for COVID-19


1. Test for current infection (NAAT)

2. Test for previous infection (Antibody)


 

1. From the mouth of the FDA:

"Nucleic acid amplification tests," or "NAAT" tests are molecular tests that detect the virus's genetic material in a sample that typically comes from a patient's respiratory system. FDA-authorized NAAT tests for SARS-CoV-2 meet the EUA statutory standard, and based on the current available data, we believe are highly accurate. This means that a positive or a negative result from a NAAT test is likely to be true. 

The NAAT test is the one we've been using from the get go, the one we had very little of, and the one we test by sticking a swab in your nose, etc. We're looking for the viruses' genetic material. One concern surrounding this tests efficacy is what exactly are we looking for, because the corona-virus is a common virus. It's important that we are looking for genetic material specific to SARS-CoV-2 and not the common cold virus.


If you test NEGATIVE

This doesn't rule out a COVID19 infection. It means that the genetic material was not present in the specimen. Perhaps there wasn't enough virus in the sample. We must consider a false negative. False negative = you tested negative, but you are actually positive. It's important to consider the patient's story (signs and symptoms), when decided what to do next. Retest? It's a bigger problem to have false negative than false positives.


If you test POSITIVE

Genetic material (RNA) was present in the specimen. You are considered "presumptively" infected with COVID19 and contagious. You will be told to quarantine for at least 2 weeks unless you are hospitalized, then depending on symptoms, more quarantine time. Before a diagnosis is made, the doctor will carefully consider clinical observations.


After you're no longer symptomatic, I understand your desire for another NAAT test to see if you are still contagious. Let's say you test negative. The next best test is the antibody test. Read below:


 

2. Antibody testing

Another type of test, called a serology or antibody test, measures the amount of antibodies present in the blood when the body is responding to a specific infection, like COVID-19. This means the test detects the body's immune response to the infection caused by the virus rather than detecting the virus itself.

Blood collection is necessary for this test.


Picture the COVID19 virus: It's come into contact with a person's lungs. The person's immune system kicks into gear in attempt to destroy the foreign invader. Among many other immune reactions, the body creates antibodies, specifically IgA and IgM at this time. Picture antibodies in the shape of the letter "Y," a bunch of them going towards the virus attaching to it. The antibodies are trying to neutralize the virus and stop it from entering cells. Over time (~4 weeks) our body will produce a different type of antibody, IgG. IgG antibodies are a bit more specific to the invader than IgA and IgM.


(This is a simplified version. Please bear with me.)


The serology/antibody test looks for the presence of these antibodies. Some tests look for only IgG, some for both IgG and IgM, and some for all three!