State should rethink approach to testing

Gov. Doug Ducey should not shut down more of the Arizona economy to manage the COVID-19 outbreak.

But he should radically change his administration’s approach to testing.

The need to do so, and the foundation for a new approach, is as follows: Tests are, and for the foreseeable future will remain, a scarce resource. Demand will far outstrip supply.

As a result, the goal shouldn’t be to make testing available to as many people as possible. Instead, the goal should be to prioritize access to tests in a way that minimizes serious COVID-19 illnesses and deaths.

Public health experts often refer to a testing and contact tracing approach to containing pandemics such as COVID-19. In such a regimen, testing is done broadly. People who test positive are quarantined. People with whom they have come into contact are traced, quarantined and tested. Overlapping circles of testing and contract tracing radiate throughout society.

A testing and contract tracing regimen can be effective. That’s principally the way South Korea contained COVID-19

without a shutdown.

However, the resources to implement such a regimen pretty much have to be on standby. Obviously, the greater the number of cases the more difficult effective tracing becomes. This is an approach to prevent an initial spread from occurring. It’s less feasible for a spread that has already taken root.

The United States did not have the resources for a testing and contact tracing approach on standby. One of the discussions that should take place after the disease has run its course is whether the country should develop such a standby capability for the future.

You will still hear public health advocates and some politicians point to testing and contact tracing as the key to getting the virus under control in a state such as Arizona. But there were never the resources available for such an approach. And now, with 3,000-plus new cases a day, the infeasibility of comprehensive contact tracing should be obvious to all.

If comprehensive contact tracing isn’t feasible, what should be the public health objective of testing?

Right now, the state is attempting to make tests as broadly available as possible, with a stated goal of making a test available to anyone who wants one.

That isn’t working out very well. Demand for tests greatly outstrips supply.

And tests now outstrip the capacity to process them. Testing is scattershot, results are long delayed.

Those who test positive can selfquarantine and some degree of contact tracing, by officials or the infected person, can take place. But this hardly maximizes the public health benefits of the testing we have the capacity to conduct.

The contours of this disease are now well-known and established. For most people, the effects are negligible or mild. The Maricopa County public health department estimates that 40% of those who become infected have no symptoms whatsoever.

But COVID-19 presents a serious risk to the elderly and those with certain underlying medical conditions. In Maricopa County, only 4% of cases result in hospitalizations and only 1% in an ICU admit. The vulnerable population, however, comprise 72% of COVID-19 hospitalizations, 83% of ICU admits and 86% of deaths.

People who fall into this vulnerable population category should be socially isolating to the extent possible. And our testing regimen should be focused on reducing their risk.

The most vulnerable of the vulnerable are those in congregate residential communities, such as nursing homes. Yet testing for residents and staff in these facilities remains episodic and spotty.

These congregate care facilities are doing a better job of protecting residents. At one point, care facility residents constituted 70% of COVID-19 deaths in Maricopa County. Today, they are under 50%.

But testing at these facilities isn’t regular and routine, with quick results. Outside of hospital medical workers, getting to that point should have the first claim on testing resources.

Beyond these facilities, people who fall into the vulnerable population should be first in line for testing. The public health goal should be to catch any infection among them as early as possible.

The testing that’s available to the rest of us should be what’s left over after access to testing with rapid results for the vulnerable population has been maximized.

With such a testing prioritization scheme, the percentage of positive tests isn’t really much of a meaningful measurement. The purpose of testing would be prevention and early detection among the vulnerable population, not to serve as a crude measurement of community spread.

This is far from ideal. But it would be a better public health use of scarce testing resources.