Correspondence: Corona Virus Testing Flawed but necessary
05 April 2020
When it comes to testing for the presence of the corona virus there are two kinds of test available. The first one is the one you see every day on your television. Using a technique called polymerase chain reaction ( PCR) a clinician takes a special made swab and runs it in the back of your throat or up your nose. This goes to a lab and a search is made for the presence of the RNA virus. The test figure that shows up every day on the news broadcasts is this PCR laboratory test. The test is the best for discovering if someone exhibiting flu like symptoms really has contracted the Covid 19 illness as opposed to something else. The test has some problems, it is both time consuming and labour intensive, and the worried patient can be left waiting for days for a result. Also the test is only about 70% accurate, probably caused by where and how the swab is placed in the throat, so potentially 30% of people may be told they donít have the illness when they actually do. The current testing results tends to support this as many people, nearly half the current number tested appear to be people who have been tested more than once.
The second test is a much faster antibody test also known as a serology test, the liquid part of the blood that excludes cells and clotting factors is tested using a small device making a prick on the finger, similar to a diabetic tester. In this case we are looking for the human antibodies the immune system makes to fight a foreign pathogen that enters the body. The problem with this test is that it also has been proven to be less than one hundred percent accurate. Also these antibodies donít develop until several days after the infection has really taken hold, you almost already know you have the disease before the detection proves it but the good thing is that these tests are faster and cheaper to do. Another problem with them is that they donít tell you if the patient is still contagious, so they need to be followed up with a second PCR test. They are not so relevant to medical science, however they could be relevant for social science, and it could help a government to find out just how many people have been previously infected without them even knowing it.
There is a now much controversy over this question, some social science says that only a small number of the worldís population has been infected and have the acquired immunity, less than 7%. Others like the Oxford Evolutionary Ecology of Infectious Disease Group presented a model for the UK saying that up to 60% of the population could already have been infected. This model has drawn a lot of criticism from the dominant social science view. The Oxford modelling has been seized on by the various ideological currents of the broad Political Right to denounce the social and economic lockdown and demand a return to the capitalist ĎNormalí. They contend that the death rate attributed to the corona virus has been artificially inflated by confused hospital reports, the death and sickness rate is not really that different from a bad flu year. So a reliable anti body test may settle the question of how many people have been infected and in turn offer a perspective on the validity of the Lockdown.
The obstacle is that the anti-body test kits are still undergoing study for reliability, the British Government has ordered 3.5 million of the tests from a consortium of private companies, they have floated the idea that the kits might even be sold to the public on Amazon. There is still no capacity available in any country in the world to carry out a thorough and accurate mass testing. One thing that might be useful is to use the new anti-body test to survey the population. This would be similar to how polling companies survey people before election time, you donít have to survey everyone to get a pretty good picture of the whole, a representative sample does just as well. So a representative sample survey based on location and age could be tested and this could give social science a much better understanding of how far on the disease has developed. On this basis a more rational discussion of Government policy response might be possible. As it stands two extreme camps are developing, the one saying the lockdown has not gone far enough, it is way too Liberal, the other that the lockdown it has gone way too far, it is totalitarian.