Coronavirus testing is becoming overwhelmed again

Americans are once again waiting in long lines for coronavirus tests — sometimes being turned away — and then waiting several days for their test results, the Washington Post reports.

Why it matters: This makes it much harder to know who has the virus and thus stop its spread, especially as the holidays approach. The longer someone has to wait for test results, the less likely it is that they'll remain in isolation until they receive them.

The big picture: Demand for tests has risen along with the spike in cases around the country, and many communities are struggling to keep up.

• "The demand is exploding across the board," Kevin Jaques, spokesperson for the Illinois State COVID-19 Testing Project, told the Post. "The labs we're working with have asked us to cap the number we do because they can't process them quickly enough anymore to meet the 72-hour turnaround."

The bottom line: Testing is an important tool, but only if it influences human behavior. That tool is becoming less useful just as the country seems to have reached new levels of pandemic fatigue.