Less than once week ago, we had our first local case. Today we have our 8th. Most have mild symptoms being monitored at home. Relatively speaking, our community is faring well. Especially when we need only look just across the river to find nearly 15,000 cases and the epicenter of the COVID-19 crisis in our country.
But the question remains, are we seeing the real picture here? Do these numbers – be it 8 or 15,000 – reflect the true number of COVID-19 cases in our communities. Not to sound alarming, but the answer is most certainly no.
First, why the rapid uptick in cases in such a short period of time? The numbers in our community are too small to draw conclusions from, but lets look at the country as a whole. As of writing this post, the US has just over 52,000 confirmed cases. 7 days ago, that number was 12,000. That means we are seeing cases double every 3.5 days. However, one thing we have learned from COVID-19 research and modeling is that without any social distancing whatsoever, the number of cases is expected to double every 6 days. So what’s happening here?
TESTING INFLUENCES THE NUMBER
Quite simply, look and ye shall find. With the availability of more widespread testing and the growing number of Americans being tested, we are going to find more cases. This is a major driver behind the faster than expected uptick. And we can expect the numbers to continue to rise. This is actually a good thing. As we identify cases, we do an even better job of containing the spread through self-quarantine of cases and more stringent self-isolation of close contacts.
Still, even with more testing, we are only identifying a subset of cases. At the moment, only individuals who are symptomatic and have a prescription from their doctor may go to a testing site. Not all cases are symptomatic. Some may have mild symptoms and decide not to get tested. We are only capturing a piece of the pie.
how many cases do we really have?
The correct answer is, we don’t know. And we might not ever know.
One way to know for sure is to screen every person in the country – see Iceland – for active virus. We’d also have to screen for the presence of antibodies to COVID-19, which would suggest that person is a recovered case. With nearly 330 million people, this is not a reality in the US. At least not in the near term.
It is even difficult to use one of the go-to tricks of an epidemiologist. Instead of screening an entire population, you screen a much smaller but representative sample and extrapolate from there. The reason this is difficult is because COVID-19 is impacting communities differently, spreading at different rates, and situations are changing almost by the hour. Every town and city in this country has its own “curve to flatten” and some may be doing a better job than others at slowing the spread. Months from now, we may be able to test for exposure to the virus in random samples across the country to get a better estimate of just how many Americans had it.
The best we can do at the moment is look to the early research coming out of countries like China, South Korea, and Italy, who have been dealing with the pandemic for substantially longer than we have. Some estimate that for every diagnosed case, there may be 7 other undiagnosed cases – the “silent spreaders” so to speak. If that translates to the US, then maybe our community has 56 cases instead of 8. Maybe the US has 350,000 cases instead of 50,000.
We’ve also heard that somewhere between 40-80% of everyone will be infected. The CDC estimates 160 – 240 million cases. What we know about herd immunity is that we need to reach a critical mass of people (typically 60-80% or higher for some viruses) who are either exposed to the virus or vaccinated against the virus for there to be enough resistance in the community to prevent additional spread. If scientists have any say, a vaccine will get here first.
we have to be patient
While the “COVID-19 PANDEMIC” ticker on your television screen might make for captivating news, lets just remember that this isn’t the whole story. Our focus should not be on the raw numbers but on slowing the spread. As we test more, we will find more cases. It might look like we are losing the battle, but rest assured, there is more to the story. Social distancing WILL WORK. And it will work even better in tandem with more testing. We have to trust the process. We have to be patient. And we have to do our best to care for ourselves, our loved ones, and our neighbors, when we all need it most. Remember, the numbers are more than just numbers. They are people.
UPDATE (3/25/20): Promising data out of New York is showing that the rate of daily hospitalization admissions is slowing down. Even though the number of cases in the state continues to rise (which is expected, see above), the key metric is daily admissions rate. Slowing the spread of COVID-19 slows the number of severe cases being hospitalized on a given day and reduces pressure on hospitals. Social distancing is working.