For the third consecutive week, COVID-19 cases that cannot be traced to a known source of infection are driving an increase in the Oregon coronavirus case load.
On Thursday, the state recorded its highest number of cases in a single day in history: 437.
The Oregon Health Authority recorded a 7% increase in COVID-19 infection in the past week, and twice as many deaths as the week before. OHA Director Patrick Allen described the increase in positive evidence as “problematic” at a press conference on Thursday afternoon.
Allen and other state public health officials attributed the increase to social gatherings and the so-called “sporadic spread,” cases that have no known exposure to any other COVID-19 case or outbreak.
The increase in such cases indicates that the virus is spreading uncontrollably in a community, state officials said.
Outbreaks linked to workplaces or other hangouts had been the leading type of coronavirus case almost every week between April and June 20, according to data from the Oregon Health Authority. Since then, outbreak-related cases have more than halved, while sporadic cases have increased more than 600 cases a week, compared to less than 400 each week.
“Large outbreaks represent a smaller proportion of recent cases,” said Allen. “These outbreaks are decreasing in proportion to other types of cases, in particular, sporadic cases.”
The increase in sporadic cases means that the virus is spreading more widely in all communities, Allen said.
The increase may also indicate an inadequate number of contact trackers and case investigators to quickly identify the causes of infections. The Oregon Health Authority said some cases are classified as sporadic due to a delay between the case report and the investigation of the case.
Fewer than 95% of patients who tested positive in the past few days were contacted by local public health personnel within 24 hours, the state said.
“I think a portion of the large number of sporadic cases is undoubtedly due to a delay in conducting timely investigations,” said State Medical Officer Dean Sidelinger. “Case investigators have been dealing with an increase in cases day by day, in the past few weeks.”
Sidelinger said the state has contracted with Oregon State University and continues to contract with Oregon Health & Science University and Portland State University to help with case investigations. The state is also hiring more case investigators, he said.
Still, state public health officials said cases of community spread are occurring in all counties in the state, rural and urban.
Gov. Kate Brown placed nine counties on a “watch list” earlier this month due to the county’s high rates of sporadic transmission and the rapid spread of the virus. Those on the watch list are mostly smaller rural counties – the county with the highest population on the watch list is Umatilla, with 78,000 residents.
The others are Jefferson, Lake, Lincoln, Malheur, Morrow, Union, and Wasco; Baker County was added to the watch list on Wednesday.
A county is placed on the watch list based on the infection rate without a link to a known source. If the sporadic case rate exceeds 50 cases per 100,000 people, it is placed on the list.
As of July 3, the lowest case rate was Clatsop County with 5.19. The highest was Morrow with 338.83. The Multnomah County sporadic case rate was 36.56, below the watch list bar.
Malheur County, a small county in eastern Oregon, has seen a 56% increase in its coronavirus cases in five days, from 302 on Saturday to 471 on Thursday. The county’s sporadic case rate on July 3 was 193.88.
In a July 9 letter to Malheur County, the Oregon Health Authority said 46% of cases in the county did not go back to a specific exposure in the past week, meaning that almost half of those cases in the county were sporadic.
The letter detailed that the county had seen a 125% increase in new COVID-19 cases, a positive test rate of 20% over the past week, and a recent increase in hospitalizations.
In response, the Malheur County Court passed a resolution Wednesday that creates new measures for social gatherings that are more stringent than is required in the current phase 2 reopening stage of the county.
Malheur county officials did not respond to a call or email to comment on the increase in cases in the county.
Sidelinger warned Oregonians to wear face masks, stay six feet away from other people, and limit social gatherings.
“Regardless of where you live, the disease is spreading,” Sidelinger said. “We need the people of Oregon to use common sense.”
– Celina Tebor
@CelinaTebor
