The U.S. public health system has been starved for decades and lacks the resources to confront the worst health crisis in a century.

Marshaled against a virus that has sickened at least 2.6 million in the U.S., killed more than 126,000 people and cost tens of millions of jobs and $3 trillion in federal rescue money, state and local government health workers on the ground are sometimes paid so little, they qualify for public aid.

They track the coronavirus on paper records shared via fax. Working seven-day weeks for months on end, they fear pay freezes, public backlash and even losing their job...