ANSWERS TO LAST WEEKS PUZZLE:
Dr. Stacey Rizza, an Mayo Clinic infectious diseases specialist, discusses the various ways COVID-19 is diagnosed and treated.
COVID-19 can be diagnosed several ways when looking for active infection.
“The most common way that testing is done is with a swab into the nose or into the nasal pharyngeal area,” says Dr. Stacey Rizza, a Mayo Clinic infectious diseases expert.
“This polymerase chain reaction (PCR) test is essentially a test looking for the genetic material of the virus.” If it’s positive, it means that person is infected with SARS-CoV-2, the coronavirus that causes COVID-19.
Dr. Stacey Rizza from Mayo Clinic gave the standard Academic recommendations for Covid Testing and treatment. I will comment on how this differs from the testing recommendations of Dr. Michael Mina from the Chan school at Harvard and the actual treatment given to Donald Trump as we speak.
I agree with the latter recommendations, and route that I would opt for, were I to catch Covid 19. TESTING, if it is to be Epidemiologically effective should offer results that are rapidly available so as to reduce spreading of the virus and treatment delay. One trouble with PCR- based tests is that they are slow. Another trouble, according to Dr. Mina, is that if they run for 40 cycles for maximum sensitivity, they may pick up viral shedding that is too minor to be infective, and may cause unnecessary precautions, such as quarantining. If they run for 35 or even 30 cycles to show only infective, actionable cases, they take several days, and even then labs do not usually report the number of cycles run, but only yes or no, positive or negative.
The RAPID TESTS detect viral protein are available within hours. They are less sensitive, but in Dr. Mina’s view, this can be a virtue, since only definitely infected patients are identified. They are cheaper, and can even be done on site. Frequent testing more than makes up for decreased sensitivity. Most tests currently available use only specimens from nasal swabs, which are uncomfortable.
SALIVA is almost as sensitive, and has one additional virtue, when it comes to testing school children. If school children are organized into learning “pods”, They can all spit into a common collector, and the pod tested preemptively, at least twice weekly. If positive The entire pod is individually tested to find who is positive. Of course if a full 20 kids are in a pod, The sensitivity of the protein test may be insufficient for positive to survive a 20-fold dilution, but this can be empirically worked out. Twice weekly testing vs. every other week is much better for reducing the number of the pod members infected at time of discovery, as the NYT has illustrated.
TREATMENT given to Donald Trump has so far consisted of more than Remdesivir. He is also receiving Corticosteroids, plus an experimental double antibody mixture, derived from both Covid Convalescent serum, and monoclonal antibodies from a “humanized” murine source. The antibodies should theoretically be given early. The corticosteroids are generally not given until a bit later, but with the reported drop in O2 sats, he may be later in the disease than we are led to believe. To my knowledge, he is not receiving his tweeted Hydroxychloroquine- azithromycin combination.
If I were infected, at age 88, I would also like the antibody treatment, but most likely would not be allowed to get it.