After weeks of steady decline, COVID-19 cases are rising in Oregon, in part due to Labor Day gatherings, college students returning to school and the state's recent wildfires, according to the Oregon Health Authority.
The state agency reported 457 new cases on Friday -- the single highest daily total since the pandemic began.
Among the recent cases was an outbreak connected to Pacific Seafood in Clatsop County, the Oregon Health Authority noted Friday. That outbreak investigation began on Sept. 15 and now has been linked to 79 people with COVID-19.
The recent wildfires in Oregon, which erupted earlier this month, likely played a role in the COVID-19 uptick, Oregon Health Authority spokesperson Tim Heider told ABC News on Saturday.
When people fled the wildfires, their social distancing efforts could have been compromised if they went to stay with families, friends or at a shelter.
There have been "testing interruptions in fire ravaged areas of the state" as well as "higher numbers of people seeking care for respiratory illnesses due to subsequent poor air quality," Heider said.
Bad air quality could make people more susceptible to COVID-19 and similar illnesses.
"Air pollution makes COVID-19 worse, especially if you have underlying conditions," Dr. Simone Wildes, an infectious disease specialist at South Shore Health and ABC News Medical Unit contributor, said last week. The combination of airway inflammation caused by irritants in smoke plus underlying conditions such as asthma or chronic obstructive pulmonary disease create a "perfect storm" for poor COVID-19 outcomes, she said.
Oregon has one of the lowest coronavirus infection rates in the U.S., Heider added.
ABC News' Dr. Leah Croll contributed to this report.