AUSTIN, Texas — Texas has surpassed 5,000 hospitalized coronavirus patients for the first time as Gov. Greg Abbott continues a dramatic retreat in his aggressive reopening of America's second-biggest state.

In Houston, county officials Friday elevated a public threat warning system to the highest level. Harris County Judge Lina Hidalgo said "We never brought the curve all the way down. We only flattened it."

Hospitalizations in Texas, reported by state health officials, have now skyrocketed more than threefold over the past month. New records are set daily, and Abbott has brought back a ban on...