Why is Pa. stay at home order county-by-county instead of statewide?

Americans are social distancing, and hundreds of millions of them are being required to do so by staying at home due to state executive orders.

More than half of states have such orders in place, but as of this writing, Pennsylvania is not among them. Instead, Gov. Tom Wolf has issued stay-at-home orders for individual counties.

UPDATE:Pennsylvania's coronavirus stay-at-home order extended to entire state

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It started with seven counties, including Philadelphia County in the east and Allegheny County in the west on March 23. Wolf said he didn't believe the order needed to be statewide.

“We want to take a measured approach to this epidemic — we don’t want to do less than we need to do, but we also don’t want to do more," Wolf said. “I think in targeting the counties we’ve targeted, we are taking that measured approach and focusing on the areas that really need it. If we are successful in this, then we won’t have to spread this to the rest of the state.”

By March 31, Wolf had grown the number of counties under the order to 33, almost half of the state's 67 total counties. Residents of these counties are only permitted to go out if a trip is deemed essential until April 30.

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While Wolf has ordered the statewide cancellation of schools, he said the county-by-county approach is based in part on existing infrastructure.

"In addition to the number of diagnoses, we’re also looking at data like the number and type of available hospital beds in the area and if the virus is spreading through community spread," Wolf said in an exclusive interview with the York Daily Record. "This is an evolving crisis. We have done somethings on a statewide basis, like schools and businesses and we’re doing somethings on a regional basis. We will continue to take a measured approach with our mitigation tactics."

Nate Chute is a producer with the USA Today Network. Follow him on Twitter at @nchute.