Testing For COVID-19
If a tree falls in a forest and no one is around to hear it, does it make a sound?
Updates on the spread of the disease and the toll it’s taking are available on excellent interactive dashboards created by academicians as well as high schoolers who are interested in data visualization.
The numbers that we hear of are typically the following: cases diagnosed; deaths; recovered cases; and serious cases. The latter are all on ventilators. Despite orders for some level of self-isolation now in place in most areas of the US, we see the number of cases now surpass those in China. This brings on many public health and personal social responsibility questions. Are the numbers increasing at this pace because we are missing milder yet contagious cases, and only counting those who have full-blown symptoms?
With the shortages in tools for sample collection and testing, special Emergency Use Authorizations are regularly given by the FDA; even so, we appear to be lagging in testing. Much of the lag is a consequence of bottlenecks in manufacturing collection and analysis kits. For example, the primary manufacturer of swabs used for sample collection, and the medium for their transport for analysis, is located in the Italian city of Brescia. Brescia is in the Lombardy region which is at the epicenter of an intense COVID-19 outbreak in Northern Italy. Brescia has lost 1,000 people to this disease. Due to hindered supply-chains, the EUAs that FDA awards are critical.
If people living in a highly affected area exhibit mild symptoms of COVID-19 (the array of symptoms is increasing with time — initial guidelines that include respiratory distress and fever have now expanded to include anosmia — loss of sense of smell, as well as gastrointestinal problems), because of the paucity of supplies they are often not clinically tested. The current approach in those areas requires tests to be reserved for those who are severely affected. And yet, we hear from the government that testing numbers per day are going up. The CDC maintains a record of COVID-19 testing by Public Health Laboratories in each state. Data ending March 20, 2020 indicated that for every 10 tests, at least 1 yields a positive result for COVID-19 — from 103,945 tested individuals, 14,250 were positive for COVID-19. As of this writing the number of people tested in the US is 540,718, with 86,548 confirmed cases — almost 16% tested are positive. But because tests are more likely administered to those who have profound symptoms, we are certainly under-counting the magnitude of the spread of COVID-19. Importantly, thanks to the onslaught of misinformation, that “FDA has approved home kits”, there are many who assume the spread to be less than it actually is — these are often the same people who flout the instructions to self-isolate. Misinformation is also compounded by the often incorrect use of the word “test”—although the FDA has approved self-administration of swabbing, swabbing is not testing, just as measuring out flour is not the same thing as having a fresh batch of cookies on the counter. Swabbing is sample collection. The test still must be done by an approved lab.
The age old question of whether a tree falling in the forest with no one around makes a sound, is likely applicable to our current state of affairs vis-à-vis COVID-19: if we don’t test widely, do we know how many have been affected? Another confounding issue around testing is timing: it is possible that symptomatic people might test negative initially but if they are re-tested at a later date they might be added to the number of positive diagnoses. But with the limited availability of tests, we can’t afford to do that. At least not yet. Data are still being gathered about the best windows for testing, as are alternate methods for testing. What we can afford to do, is practice social distancing. Because we are so distanced from flattening the curve.
