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COVID-19 Testing: Value and Availability

May 29, 2020   |   By Steven Luu

Many GreenField Health patients have reached out to us about COVID-19 testing options, so we wanted to share some information about the value and availability of testing. (At the bottom we also have additional information about some of the technical components of testing and COVID-19 for those who are interested.)

Although testing resources for the COVID-19 strain of coronavirus remain in short supply in Oregon and nationwide, we’re pleased to let our patients know that GreenField has access to testing kits for both the coronavirus and antibodies that might remain post-infection.

Before patients rush in for a test, however, please consider whether you are at high risk of being infected. Are you displaying symptoms of infection? Have you been in prolonged close contact with someone who has tested positive? If the answer to either question is yes, you should contact GreenField to discuss whether a test is right for you.

On the other hand, if you and your family have been isolating at home, keeping trips and social interactions to a minimum, wearing a mask when out and about, and generally following guidelines on reducing virus transmission, then the odds that you have the virus are low. Keep up the good work and hold off on a test.

If you do come in for a COVID-19 test, our trained providers will collect a sample from your upper respiratory tract by inserting a swab into your nose. We send the sample to whatever lab your routine blood tests would go to, which is primarily determined by your insurance. Typically, the results are available in 12 to 24 hours.

Our supply of antibody tests is much more limited. We will therefore be more selective in when we use them. Contact your GreenField health care team if you have special circumstances that require this test. The test is performed via a finger prick to collect a blood sample. We anticipate that the limited supply will run out soon, and it remains unclear when GreenField will be able to secure more.

As always, we aim to keep you as informed as possible with all the information available. If you have any questions, please reach out to your health care team. Remember, we’re here for you, we’re open, we’re not going anywhere, and we’re more available now than ever.

 

Technical notes

Some GreenField patients have detailed questions about COVID-19. We hope that this additional information will answer most of them. If you have other questions about how the COVID-19 coronavirus could impact your family’s health, your GreenField care team is happy to discuss them with you.

 

Terminology

It’s important to get clear what we’re actually talking about. The media often uses the terms ‘COVID-19’ and ‘coronavirus’ interchangeably, but they aren’t the same, and neither is the virus.

‘Coronavirus’ is a class of viruses that commonly causes upper respiratory infections. There are many coronaviruses, some of which infect humans and many strains that infect non-human species.

‘COVID-19’ is the disease caused by a particular strain of coronavirus identified in 2019.

The virus responsible for the COVID-19 disease is Severe Acute Respiratory Syndrome – Coronavirus, Strain 2 (SARS-CoV-2).

This is the second strain of SARS-CoV to have caused human outbreaks of severe respiratory diseases. The previous (Strain 1) caused the 2002-04 SARS outbreak. 

To summarize, SARS-CoV-2 is a type of coronavirus that causes COVID-19 disease.

 

Prevalence

When GreenField and other health care providers test for the virus, we are testing specifically for SARS-CoV-2, not other coronavirus variants. Because testing has been limited to date, many reported cases, especially early on, were presumptive. That means that the patient had symptoms consistent with COVID-19 but were not necessarily tested.

When looking at the total number of identified cases – presumptive or tested – it’s important to remember that it does not include many infected patients. Some people do not get tested despite having symptoms. The disease is also known to have an unusually high rate of asymptomatic infections – people have it and spread the virus but never experience any of the symptoms.

As of May 28, the Oregon Health Authority has documented 119,555 tests conducted, and 115,561 of them returned with negative results.

Locale                                   Cases                    Deaths

Oregon                                    4,086                    151

Multnomah County              1,103                     59

Washington County              715                       17

Clackamas County                304                       11

View the current statewide daily report.

 
Testing
There are two types of SARS-CoV-2 test available at this time. One set of tests collects samples through the nose or mouth and tests for the virus’ presence in the upper respiratory system. The other set of tests collects a blood sample and checks for antibodies.

A. Virus tests

Nasopharyngeal swabs (through the nose) or oropharyngeal swabs (through the mouth) collect samples that then are tested for the virus. The test itself uses a technique called nucleic acid amplification to detect the virus's genetic material. The test is supposed to tell us whether someone has live virus replicating in their upper respiratory track. The test is also referred to as polymerase chain reaction (PCR).

The challenge is that the research hasn’t conclusively demonstrated that a positive test means that someone is actually infectious – if they are spreading enough of the virus to infect others via coughing, sneezing or even just talking. So while we worry about a positive test, we’re not yet 100% sure of the implications. It does appear to mean that you are or have been infected, but not that you are necessarily infectious.

B. Antibody test

The antibody test is a blood (serology) test. It looks for whether or not an individual has built up antibodies to SARS-CoV-2. When a person gets an infection, their body develops several different types of antibodies to help fight the infection. IgM antibodies form very quickly – within a few days to a week of the onset of infection. They are followed by IgG antibodies after about 4 weeks. The IgG antibodies are the one that last long-term in the body and often provide immunity to future infection.

There are several tests on the market now for SARS-CoV-2 antibodies, but the federal Food and Drug Administration has not approved any of them yet. At best, the FDA has acknowledged the veracity of the test producer. In reviewing antibody test options, GreenField has found that some test for just IgG and some for both IgG and IgM. We have the latter type in limited supply at GreenField.

 
Who should be tested?

This remains, perhaps surprisingly, unclear. As you are likely aware, public testing availability is increasing, with fewer requirements for who should be tested and less prioritization. Even so, some emergency rooms are sending some people home without testing unless they are sufficiently ill to be admitted to the hospital. This is due to a shortage of testing kits.

There remain some questions about what a positive test really means. A positive result found the virus RNA in an individual’s upper respiratory system. That information is helpful from a diagnosis perspective, but we don’t know if it means that individual is infectious – if that individual is shedding virus in the secretions so as to be able to pass it on to others. Viral RNA can at times be detected in someone’s upper respiratory tract – their pharynx – for weeks after they had the infection. We also know that having the infection doesn’t mean having the disease – many people contract the SARS-CoV-2 virus but have no symptoms so don’t have the COVID-19 disease.

For the antibody test things are arguably even more murky. Tests for IgM and IgG antibodies against SARS-CoV-2 are now on the market and starting to be offered, but their quality has not yet been validated. A positive antibody test implies that the individual came in contact with SARS-CoV-2 at some time in the past, but when is not certain.

Most important, we don’t know if having the antibodies means that you are truly immune to getting the infection again. With some diseases, the presence of antibodies is not enough to prevent future infection or spreading a virus.

Based on what we currently know, a positive antibody test may give people a false sense of safety and immunity – a false sense that they won’t get it again, and that they can’t pass it on to others. For this reason and due to the general shortage of testing equipment at this time, GreenField is reluctant to administer antibody tests except under special circumstances.