I would feel comfortable if a coronavirus test were negative before leaving on a trip for Thanksgiving. I would feel ecstatic if two tests yielded the same result. What if one test came back positive and the other negative?
Several months ago, I wrote about one method to treat viral infections. It was to have a cheap home test kit that people could test themselves before leaving for work, or shopping, or vacation. Companies could test their employees daily. Football stadiums could test everyone entering.
https://www.sciencedaily.com/releases/2020/11/201120142134.htm A recent study conducted by the University of Colorado at Boulder and Harvard University predicts that COVID-19 could be crippled within weeks if a cheap home test were available to detect the virus. And the test does not have to be super-sensitive.
The key is frequent testing with rapid results. A super-sensitive test that takes 24, 48, or 72 hours to get results is good, but it will not stop the spread of disease. A test that gives results in five minutes and might be correct 95% of the time (19 out of 20 tests) allows people to self-quarantine faster without exposing others to the virus.
https://www.sciencemag.org/news/2020/08/radical-shift-testing-strategy-needed-reopen-schools-and-businesses-researchers-say An infected person who is contagious can infect others. Each of those people can infect others. And so on. People must know early on whether they are carriers of the disease to stop the infection of others.
Mathematical models tested three hypothetical scenarios. One large-city scenario is widespread testing everyone every three days with rapid results from a less sensitive test. It predicted a reduction of infection by 80%.
The current PCR (polymerase chain reaction) test is more sensitive and takes longer (up to 48 hours) to get results. That test was plugged into the same model and the reduction of infection was only 58%. During the two days, people with COVID-19 awaiting results had the opportunity to infect others.
In a similar scenario in a large city with four percent already infected, a rapid testing and reporting system can reduce the infection rate by 88% when three out of every four people were tested every three days. The model predicts the virus would die out in six weeks.
https://www.nejm.org/doi/full/10.1056/NEJMp2025631 One reason why frequent testing is needed is that it takes time for the virus to multiply to a level that it can be measured in the body. If you were infected one hour ago, you probably would not be able to infect other people just by being around them. Let a couple or more days go by and the level of viral load in the body is now high enough to detect the virus.
The COVID-19 virus can increase from 5,000 particles to one million viral RNA copies per milliliter of a sample in less than 24 hours. The PCR test can detect as little as 5,000 viral RNA copies per milliliter. The RT-lamp (reverse transcription loop-mediated isothermal amplification) needs around 500,000 viral RNA copies of the virus per milliliter. The antigen test requires around 5,000,000 viral RNA copies of the virus per milliliter of sample.
Cheap, simple, home tests with rapid results would allow most people to test daily, several times daily if necessary, to verify that they are positive or negative for the virus. When positive with one test, a protocol of testing two or three more times would be required to confirm the positive results. Testing daily would remove infected members from society and reduce the rate of infection.
Live Longer & Enjoy Life! – Red O’Laughlin – RedOLaughlin.com