Data: The COVID Tracking Project. Note: Vermont and Hawaii were not included because they have fewer than 20 cases per day. Chart: Andrew Witherspoon/Axios

The United States' alarming rise in coronavirus cases isn't due to increased testing — particularly not where cases have grown fastest over the last month.

Why it matters: The U.S. doesn't yet know what it looks like when a pandemic rages on relatively unchecked after the health system has become overwhelmed. It may be about to find out.

The big picture: The number of tests completed in the United States is going up, which is a good thing. But the number of new cases is increasing faster.

  • The situation varies state by state, but the gap between testing and cases is generally largest in the cases with the fastest-growing coronavirus outbreaks, like Florida and Texas.
  • But in some places, like the District of Columbia and New York, testing has grown faster than new cases — a good indicator that these outbreaks are under control.

My thought bubble: Even if testing did explain why America's official coronavirus caseload has doubled over the last month, that would be little cause for comfort; it'd only indicate that we have a worse problem than we'd thought.

  • But the reality is that states like Arizona, Florida and Texas are struggling to meet the demand for coronavirus tests, meaning the pandemic is already outpacing those states' ability to respond to it.

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Coronavirus hotspots begin to improve

Data: The COVID Tracking Project, state health departments; Map: Andrew Witherspoon, Danielle Alberti, Sara Wise/Axios

Coronavirus infections are falling or holding steady in most of the country, including the hard-hit hotspots of Arizona, California and Florida.

The big picture: A decline in new infections is always good news, but don't be fooled: the U.S. still has a very long way to go to recover from this summer's surge.

Aug 5, 2020 - Health

Florida surpasses 500,000 confirmed coronavirus cases

Emergency at Coral Gables Hospital near Miami on July 30. Photo: Chandan Khanna/AFP via Getty Images

Florida has reported over 500,000 total confirmed coronavirus cases as of Wednesday, according to the state's health department.

Why it matters: Florida joins California as the only two states to surpass this milestone. Texas, which is reporting the third-most confirmed cases in the country, is not far behind, according to Johns Hopkins data.

Updated Aug 5, 2020 - Health

N.Y., N.J. and Conn. to require travelers from 35 states to quarantine

Photo: Spencer Platt/Getty Images

Travelers from 35 states are now required to quarantine for 14 days when traveling to New York, New Jersey and Connecticut, per New York state's health department.

What's new: New York City will set up bridge and tunnel checkpoints to enforce the quarantine order, Mayor Bill de Blasio said Wednesday, per the Wall Street Journal.