EVERETT — Snohomish County could be the first in the state to slip back to Phase 1 of the governor’s reopening plan after a concerning spike in new COVID-19 cases, Executive Dave Somers said Tuesday.

In the past week, the county has seen 42 new cases of the virus per 100,000 residents — the highest it’s been since late April. To enter Phase 2, the benchmark was 25 cases per 100,000.

The county is currently out of compliance for three of five key factors to qualify for Phase 2. Increased activity and a lack of social distancing and mask-wearing are contributing to the spike, local leaders said. Under the governor’s “Safe Start” plan, both county officials and the state Secretary of Health can revert a county to a previous phase.

“A week or so ago, I would have thought it was a remote possibility. I don’t feel that way anymore,” Somers told reporters Tuesday. “Going back to Phase 1 is clearly one of the options that could be in front of us.”

An increase in hospitalizations or deaths would almost certainly lead to the county reverting back to the first phase, he said. So far, those numbers have stayed flat.

However, it could take weeks for that to occur, said Dr. Chris Spitters, the county’s top health officer. On average, one to three people in Snohomish County die each day due to COVID-19, he said.

The latest cases show community spread of the virus is increasing. In previous weeks, cases were mostly confined to specific clusters, which were easier to track.

Social distancing and wearing a face mask will prevent spreading the virus, health experts say.

With the July 4 weekend approaching, health officials are worried large gatherings will turn into “super-spreader” events.

In Stanwood, a house party on June 19 drew 40 to 70 attendees, and at least one has tested positive.

Large gatherings put a strain on the county’s contact tracing, Spitters said. There are too many exposed people to track down, and contact information isn’t always available.

If you’ve been exposed to the virus, you need to isolate at home for 14 days and seek testing, he said.

The health district has been receiving increased reports of large parties and events, Spitters said. Going forward, those will be forwarded to the Snohomish County Sheriff’s Office.

“If we do receive reports, each incident will be responded to and handled on a case by case basis,” sheriff’s office spokeswoman Courtney O’Keefe said in an email. “The Snohomish County Sheriff’s Office will continue to communicate with and encourage community members to make safety-focused decisions, and follow all health-based directives from the governor, as well as state and local health officials.”

The spike in cases is not being caused by an increase in testing, Somers said.

The number of tests administered has stayed relatively flat at 2,500 per week, Spitters said. The percentage of individuals testing positive has also jumped, indicating a higher level of infection in the community.

Additionally, no cases have been linked to protests against police brutality, he said last week.

The county has been in Phase 2 of the governor’s “Safe Start” plan for three weeks.

Going back to Phase 1 would shutter restaurants, retail stores and barber shops, that had previously been closed since March.

Samantha Hill, a spokesperson for Bluewater Distilling in Everett, said the restaurant is urging Somers’ office to stay in Phase 2.

“Restaurants are fully compliant and should not be punished for the spike,” she said in an email. “Going back to Phase 1 would be devastating and would crash this industry in our county.”

On Friday, local leaders announced they would not be submitting an application to advance to Phase 3, which would allow gatherings of 50 people and reopen gyms, movie theaters and libraries.

Across the state, several other counties have also experienced recent spikes in COVID-19 cases.

Last weekend, the governor announced no counties would advance to Phase 4 of his plan, for now. In Phase 4, there are virtually no restrictions on businesses and social activity.

The state Department of Health is asking Washingtonians to avoid unnecessary travel this summer. If you’re going to leave the house, stay within your county or region, state Health Officer Dr. Kathy Lofy said in a Tuesday news release.

“If there’s a lot of cross-state travel this summer, that could spread disease around the state,” she said.

Joey Thompson: 425-339-3449; jthompson@heraldnet.com. Twitter: @byjoeythompson.