If you’re watching daily case reports of COVID-19 in Alaska and you’re not sure whether you should be concerned, you’re not alone. And there’s good reason for that: The stream of numbers and what they mean can be overwhelming. Total cases, active cases, recovered cases, deaths, hospitalizations, tests, R-naught values, mortality rate — it’s enough to make your head spin. So which numbers are the most valuable, especially with regard to determining what’s safe for you? It depends, but in general, the numbers that are most valuable are the ones that give us the clearest picture of where we are right now — and where things might be headed.
One source of good data about the ultimate severity of COVID-19 and its impact on Alaska is its bottom line: the death toll. By that accounting, Alaska is doing relatively well, with only 14 total resident deaths so far. But there are a few big problems with looking at deaths to judge how bad things are. First, death numbers can be skewed by clusters of cases among people who are vulnerable to the disease, such as in nursing homes, a phenomenon Alaska has been fortunate to largely avoid so far. The other problem with counting deaths is that they often come long after a swell in cases — weeks or even months later. Deaths will be the ultimate metric for the severity of the COVID-19 pandemic, but it’s a number that only provides a true accounting when we’re looking in the rearview mirror, not while we’re still in the midst of outbreaks.
Hospitalizations, similarly, lag behind as a measure for the current strength of the pandemic. Often, cases are diagnosed days or weeks before patients require hospitalization, so if states or countries wait until hospitals are nearing capacity to enact more stringent safety measures, it’s often too late to avoid overburdening the system, as countries such as Italy and Spain discovered in the pandemic’s early days.
One number that’s received a lot of attention is called R-naught, or R0, an epidemiological variable that represents the number of people that each positive case infects. If that number is exactly 1, it means that each positive case will replace itself, and the number of active cases will remain more or less constant until herd immunity is achieved or a vaccine is developed. If the R-naught value is above one, cases will grow exponentially — a classic outbreak scenario. If it’s below one, cases will eventually decline to zero.
But in a low-population state like Alaska, small differences in the new case count can make the R-naught value very “noisy” — it jumps up and down, making it harder to get a clear picture of how bad things are. The state’s projections on its COVID-19 dashboard have see-sawed wildly, indicating R-naught values well above 1 on one day and slightly below one only a few days later.
The easiest number to digest is the number of new cases per day — it’s easy to comprehend and it’s the first public data we have that shows the number of diagnosed infections is getting better or worse. But that raw number can be misleading, too. As political leaders and health officials have pointed out, testing capacity has increased. Therefore, increasing case counts are sometimes less indicative of an outbreak getting worse than a reflection that cases — particularly presymptomatic and asymptomatic — that might have been missed before are now being diagnosed.
Additionally, a significant portion of new cases in Alaska in the current surge of COVID-19 cases has been in nonresidents, most of whom — particularly in the seafood industry — are supposed to be isolated from local communities. It’s not completely clear how well the industry’s isolation plans are being followed by workers, but based on the low amount of community spread in fishing communities so far, fisheries workers and Alaskans appear to be largely separate from one another. The aggregate number of new cases and their locations are still helpful, but they aren’t as clear of an indicator as they can appear.
The best we can do
Ultimately, one of the clearest depictions of the severity of the COVID-19 situation is the percentage of tests that come back positive. Like R-naught, this number wobbles a fair amount — an issue that can be partially addressed by taking a rolling average of the past several days — but it helps to clear up the question of whether more people are getting sick or we’re just testing more.
In the early days of the pandemic, the percentage of positive tests in Alaska was regularly in the 2%-3% range. When the state’s “hunker down,” travel quarantine and other health mandates were in effect, that percentage dropped to near zero. Since the beginning of the surge in cases that started after re-opening measures were implemented, the percentage of positive tests has risen again, to an average of close to 1% since the beginning of June. That percentage isn’t as bad as the initial surge of cases, and it’s not nearly as severe as in some states contemplating a return to “hunker-down” status — California, for instance, has averaged a positive test rate of roughly 5% in the past two weeks — but it’s still cause for concern and a reminder that we can’t afford to get lax in our observance of health mandates, wearing face coverings and distancing.
Each positive case, after all, is another opportunity for COVID-19 to gain a stronger foothold here. If we want to keep the roughly one-third of Alaskans estimated to be particularly vulnerable to the disease, as well as show that our economic re-opening isn’t a poor risk, it’s all of our responsibility to step up. Maintain distancing and wear face coverings in public. Limit your exposure to people outside your household as much as you can. We can’t afford to screw this up.