COVID-19 is a strange and complex disease. What is even stranger is the testing process and how it works. Local officials have mentioned that there are problems with being able to obtain tests and the associated items needed for testing. Over the past several weeks I have spent hours researching the processes behind testing and complex problems associated with just being able to get a test. Part of it is supply chain and the other part is economics.
COVId-19 is a dangerous and deadly disease. While it might not powerful enough to kill a large number of people rapidly, it can kill a late number of people over a period of time. We already know that the disease hides itself in people who exhibit absolutely no symptoms whatsoever. That makes testing even more important.
Experts at the Baylor College of Medicine say that the best thing that a healthcare system can do until there is a vaccine, effective and proven treatment or herd immunity is test.
The truth is that diagnostic testing for COVID-19 has ramped up pretty fast since the early days of the pandemic. It was not until January 5, 2020 that the first genetic sequence was published for COVID-19. Within days of that, researchers quickly developed testing protocols to look for the disease.
By early February hundreds of people around the world were being tested for COVDI-19. Just a few weeks later towards the end of February, the world as a whole were testing thousands of potential victims. Now, in August off 2020 we see millions of people “trying” to get tested and the number of people here locally who are getting tested does not seem to be increasing.
The process of testing here locally has been plagued with problems from the very beginning. While it seems worse here in our backyard because of mismanagement and poor communications, this problem is not unique to Corpus Christi and Nueces County. While it does seem that there has been blatant Polk all gamesmanship and profiteering from local leaders, Christus and others, there is no doubt that we are not alone in the fight to understand testing. However, there is no doubt that local officials would rather send you through a private lab than use public testing resources which have been available since day one.
The simple point here is that we have reached a point where testing is becoming more of a problem than a solution. The system itself needs to be scrutinized and experts say there needs to be a complete overhaul for it to properly function. The problem? Money and profits.
At the heart of any coronavirus test is what is known as Polymerase chain reaction (PCR). The process copies DNA or RNA enough to be studied for a specific reason. The various steps in the process of PCR testing require very specific temperatures to be completed. This very process requires a machine called a “thermocycler.” These machines can reach these specific temperatures very quickly and accurately, allowing for study of the cultures. While that sounds all good and great, that technology comes at a cost.
The cheaper thermocyclers range from the thousands of dollars. The more elaborate type needed for COVID-19 testing is much more expensive. Right now, it just is not practical for doctors offices to invest in these more expensive machines. However, there are some less expensive point-of-care tests being pushed to market, but those are highly inaccurate and often much more expensive.
If you follow the point so far, the real read is that while collecting samples can be done almost anywhere, getting them processed is the real challenge.
One of the largest testing companies in the United States is Quest Diagnostics. Over the past several weeks, I have spent researching this topic, I have worked alongside folks from Quest and other labs who process the collected specimens. It is a fascinating process and one that is without a doubt vital to slowing the spread of COVID-19.
Each day, Quest Diagnostics process about 130,000 COVID-19 tests from around the country. That is a mere fraction of those that are collected. Each night, a flight leaves Dallas and makes stops at Corpus Christi International Airport and generally makes its way down to McAllen and then back north to San Antonio and then finally back to Dallas once again. This plane is usually a Pilatus PC-12 that carries COVID-19 and other tests back to Dallas for processing.
In theory, this system would work pretty well, right? But it is not flawless. While this is in fact very effective, other economic burdens have decreased the effectiveness of this process.
For a test to be conducted it takes about 20 different items ranging from swabs, re-agents and test tubes, among other things. The case in point is that if there is a breakdown in the supply chain with any one of these items, testing can, and often does grind to a halt. Economic forces are in play and are impacting the process heavily.
Here in the United States, we have learned that an overwhelming majority of testing is being conducted by private labs and hospitals. Their overall goal is not entirely about patient care and outcomes, but about profits and making money—even if it is “non-profit” like Christus Health claims that they are.
In traditional economics you generally try to avoid economic monopolies because one company can grab up too much of the power. An example of this are cell phone carriers. In the United States right now there are in essence three major carriers providing nearly 93% of the infrastructure. Because they have been able to monopolize the system they can control what others charge for the use of the infrastructure. That is similarly what we are running into with testing.
When it comes to COVID-19 testing, the process is very much the same. You end up with hundreds of thousands of people needing the product (testing) and a few companies are basically bidding against each other to make a buck.
For instance, if the federal government was the largest purchaser of testing supplies and resources, then there would be fewer alternatives and much like the Medicare/Medicaid marketplace, providers would be forced to simply accept whatever the government chooses to pay. While it doesn’t always work out the best when you have a central purchaser, it does at least help control the cost and distribution of the needed supplies.
Quest Diagnostics, for instance has a huge buying power. They can in theory purchase more tests for less money than many small countries. However, they then have to compete with smaller labs and hospitals for the other supplies such as test tubes, gloves, gowns and re-agents. Because of this, Quest and their major competitor, LabCorp have been able to collect more tests than they can process in a day. That leads to a delay in obtaining test results. On average, Quest Diagnostics collects some 22% of all of the total tests completed in the state of Texas each and every day. Because of the lapse in the supply chain, you end up with delayed processing, or test results.
Because of this, test results can linger for two weeks or more to come back. That results in another problem.
Tests that take so long to come back are of practically little to no use whatsoever. The reason being is that while the person woh is asymptomatic may have exposed hundreds of thousands of people along the way. The problem here is that the asymptomatic patient or the mildly symptomatic person might not properly quarantine the entire time that they are waiting for their test results.
Because of this there has been a major push to revamp how tests are conducted. Quest has been recently granted permission to conduct what is known as “pool testing.” To date, this has been the only application that I have found to be approved by the FDA.
Pool Testing Explained
In simplicity, pool testing is where the lab can combine 4 tests together in the machine. If they generate a negative result, then all of the test samples are considered negative. If the group tests positive, the samples are pulled out and tested individually. This is where the plan gets complicated.
If 100 people are tested for COVID-19 traditionally, that would mean that you have to preform 100 individual tests. Using “pool” or “group” testing, you would break that down into 25 groups of 4 tests. Out of those, you’d expect that using current national averages, some 32% of the pooled tests would come back positive. Then you go back and test those positive groups individually. In practice, you took up only 57 testing slots to get 100 results.
The problem with this is that this process only works if there are enough tests to result in a small number of positive cases. If you end up having a high positivity rate then this would result in a higher number of results having to be individually tested. Using the 100 number, if a high percentage of those tests came back positive, then you’d end up taking up more space and resources. You would end up using 105 testing spots or more, to tests those positive groups.
You end up with that number because if you take 20% of the positive cases and then have to retest those groups of 4, you end up taking up the additional space. This does not work in hotspot places such as meat packing plants, healthcare facilities and locations such as McAllen where you have a very high number of positive cases.
Pooled sampling can in essence work if you have low numbers. You could group 10, 15, or even 20 test samples together. But if a high number of those come back positive, then you have a real problem. So what do you do?
PCR testing is very effective, but is very time consuming.
It takes a number of days before a person begins showing symptoms of coronavirus. Then it would take another day or so for them to decide to get tested or find a place to even get tested. From there, it could take several more days or even weeks to get the results. The person being tested is likely to have not followed all quarantine procedures and may have potentially infected hundreds of other people along the way.
By using traditional or even group testing, it could take weeks to determine of a places is becoming a so-called “hot spot.” Some researchers say that there is a solution for that. It is located in our wastewater.
Researchers have determined that since wastewater is collected in geographical locations, they can easily test that wastewater for the COVID-19 DNA signature to see if there might be a potential breakout in a specific area.
Research as proven that sewage testing can tell as much as a week faster if an area is experiencing an outbreak. That would allow local governments to potentially identify hotspots before they become a problem.
Going back to the topic of pool testing you could learn from sewage testing if you need to do traditional/individual testing in an area or if you could get by with “pool testing.” These researchers believe that the higher level of COVID-19 you have in the wastewater, the more likely you are to find a specific outbreak area and you would know how to respond for testing before it becomes largely ineffective like it has here locally.
By using the wastewater testing process, governments could, in theory, identify lower-risk groups that could be pooled together and higher risk groups that need to be tested individually.
The cost to preform a group test could reduce the overall cost of a test to only $3-5 dollars per test, making the ability to get tested even more a reality. And that could be absolutely vital.
We are coming up on the fall season when the flu really hits. The problem with this is that flu symptoms and COVID-19 symptoms are generally identical. That means that more and more people will require some sort of testing for coronavirus. That also means that the demand for supplies will increase.
We heard about that this week from Governor Abbott. He stressed that the need for testing and the demand will increase drastically by October. As of today, testing is rendered nearly useless because people do not trust local officials, and they do not have accurate and reliable data. Because of the flu season, the demand for COVID-19 testing will increase even if the overall infection rate is actually lower. The problem with testing is that the supplies that are being produced now are being used right now. There is no stockpile of supplies anywhere.
That could be the real problem and nobody knows where that is going to lead.