Submitted by R. Sidney Cloud MD.
There appears to be a need for further explanation about the meaning of and usefulness of testing for viruses, specifically Covid-19. This need is apparent as the President of the United States continues to say that the number of cases is caused by the amount of testing; claiming that if there was less testing there would be fewer cases.
Testing for the virus does not cause the disease. The disease occurs when a susceptible individual ingests or inhales enough active virus particles to become infected. Testing for the virus only shows the number of cases that are known to be actively shedding virus. This known number is always lower than the actual number of cases.
Doing less testing only increases a false sense of security which will cause people to be less careful and thus increase the number of those infected and dying. Refusing to count the number of mountain lions around does not keep you from being lunch.
A person can be infected, have no symptoms, and test negative only to become contagious in the next few days. So what is the usefulness of testing? It is essential in knowing how to take preventive measures to stop the spread of the disease and the resulting deaths.
At this time there are no treatments with medications or plasma antibodies that are known to be effective in treating Covid-19 infections. There are some on going trials of drugs and antibodies that may effective, but these are not available except for controlled trials and VIPs such as the President (and a few others).
Viruses have been very resistant to drug treatment and Covid-19 may not be an exception. Antibody treatment may be effective, but the need currently is much greater than the supply and it is unknown if it works or how well and in which patients and three or four other ‘and if’s’. So shutting down person to person contact, masks, social distancing, and hand washing are the only treatments / preventions available now to stop or slow the spread of disease.
Without adequate testing, including genomic testing, as much of the entire economy as possible has to be shut down; with enough testing and contact tracing individuals known to be infected and those known to have been exposed can be isolated and a general shut down avoided. Testing for the virus lets a limited approach be effective. If you don’t know who has or is likely to have the disease you are forced to shut down everyone.
This past weekend the White House announced they were no longer trying to control the virus, so it is up to each of us to take those effective measures of prevention you have heard so often this year. Take care of yourselves and others.