Oregon's first confirmed case of COVID-19 was on Feb. 28 in Washington County, the suburban county west of Portland. Until nearly two weeks ago, Washington County still had more cases than Multnomah County.
But Portland has overtaken the suburbs.

Last weekend, Multnomah County crossed the 500-case threshold, and Washington County had just 408 cases.

Multnomah County also has 28 deaths, more than triple Washington County's eight deaths.

Multnomah County has tested nearly double the cases of its western neighbor, and has a slightly lower rate of positive tests, but public health officials have yet to explain exactly why Multnomah County's cases have risen so much faster. One factor: Two of the nursing homes that have seen clusters of COVID-19 deaths are in Portland.

"Washington County had the state's first reported case in the state, so that area saw more cases earlier than other jurisdictions," says Multnomah County spokeswoman Kate Willson. "We have a larger population, so we would expect to be on different timing and see more total cases if Multnomah County follows the same pattern."