The number of coronavirus cases increased in the vast majority of states over the last week, and decreased in only two states plus the District of Columbia.

Why it matters: This is a grim reminder that no part of the United States is safe from the virus. If states fail to contain their outbreaks, they could soon face exponential spread and overwhelmed health systems.

Flashback: A month and a half ago, shortly after states began reopening, cases were decreasing or holding steady in most states. The rapid spread of the virus since then shows how quickly the state of the pandemic can change.

• Florida, for example, saw cases decline by 14% between May 4 and May 11. This week, cases increased by 109%.

The big picture: States continue to set new records for their number of coronavirus cases and hospitalizations on a regular basis.

• Officials in Los Angeles County have warned that hospitals could run out of beds in two to three weeks, the L.A. Times reported.
• Just yesterday, Texas, Arizona and Georgia reported record-high case numbers.

Between the lines: Axios uses a rolling seven-day average to minimize the effects of any abnormalities in how and when new cases are reported.

Some states saw large increases in testing over the last week, which could account for the growth in cases. But in 36 states, case growth exceeded testing growth, meaning that the spike in cases generally isn't due to increased testing.

• In Washington, for example, testing increased by 92% over the last week while cases increased by only 33%.
• But in Florida, testing increased by only 69%. In California, testing increased by 20% and cases increased by 35%, and in Tennessee, testing increasedby 32% and cases by 61%.
• In a handful of states, including Oregon, Arkansas and Louisiana, testing actually decreased.

What we're watching: Hospitalizations are rising nationally, but the death rate continues to decline. That's at least partially because younger people are getting infected at high rates, but they can easily spread the virus to more vulnerable family members or coworkers.

• Governors in some of the hardest-hit states have taken nominal steps to control the pandemic, like closing bars.
• But these states' public health infrastructures — like their testing capabilities — are quickly becoming overwhelmed, and there's no reason to think that as people continue to interact with one another, their hospitals aren't at risk of getting overwhelmed too.

The bottom line: The United States initially avoided the nightmare scenario of coronavirus patients dying untreated in hospital hallways — but this scenario is no longer out of the question.