HERMISTON, Ore. – Preliminary results from random door-to-door TRACE-COVID-19 sampling by Oregon State University last weekend suggest 17% of the Hermiston community has been infected with the coronavirus.
“The results of this study are a significant warning,” said Hermiston Mayor David Drotzmann. “We now have a clearer picture of how many people are carrying this disease without knowing it, and how rapidly it is spreading family to family, household to household.”
TRACE stands for Team-based Rapid Assessment of Community-Level Coronavirus Epidemics.
The OSU public health project began in April in Corvallis and later expanded to Bend and Newport.
“Our results indicate the virus is extremely widespread in Hermiston and more prevalent than previous data had indicated,” said Ben Dalziel, assistant professor in the College of Science at OSU and co-director of the project.
To that end, Gov. Kate Brown on Thursday ordered all of Umatilla County to return to the state’s “stay home” status due to the rising number of cases there.
In Hermiston, 29 two-person field teams canvased 30 neighborhoods, with 249 of the households visited, or 44%, agreeing to participate.
In all, the field workers received samples from 471 people, and 41 tested positive for SARS-CoV-2, the virus that causes COVID-19. TRACE modeling, which takes into account the sensitivity of the test and the locations of the positive individuals, estimates the prevalence of the virus last weekend was 169 out of every 1,000 people in Hermiston.
That translates to nearly 3,000 infected people in the city overall.
“This study confirms what we have feared based on weeks of troubling data from the Oregon Health Authority: The coronavirus has spread throughout Hermiston and threatens the entire community,” said Oregon Gov. Kate Brown. “Umatilla County is now in a ‘baseline, stay home’ status and we must do everything possible to contain these outbreaks. Wear your face coverings, watch your distance and wash your hands. I’d like to thank the TRACE team at Oregon State for their hard work on this important research.”
In announcing prevalence results, the TRACE team follows reporting policies used by the Oregon Health Authority and local health departments.
“These data reaffirm what we learning from public health investigations, that in addition to outbreaks, there are many cases of COVID-19 which are sporadic,” said Dean Sidelinger, health officer and state epidemiologist at the Oregon Health Authority. “This indicates wide community spread.”
Oregon State University researchers also gathered multiple wastewater samples from Hermiston and neighboring Boardman in early July and again from July 21-24. Analysis of the wastewater samples “showed consistently strong viral signals in both cities that have remained very high and not decreased over time,” said lead researcher Tyler Radniecki of the OSU College of Engineering.
“The levels recorded are significantly higher than any of TRACE’s previous wastewater samples,” he added.
Both the door-to-door and the wastewater results indicate the virus is widespread in Hermiston and the situation is serious and warrants immediate action, said TRACE leaders.
“Half of the 30 randomly selected neighborhoods we visited had at least one positive participant,” said Dalziel. “This means that the virus is very widespread within the community, not clustered in only a few locations.”
As well, 80% of those Hermiston community members who tested positive in the TRACE sampling did not report symptoms of the virus.
“This result is cause for concern because efforts to monitor and stop spread that are based on symptoms will miss many infected individuals,” said Dalziel. “The large number of infected people without symptoms combined with the widespread distribution of the virus within Hermiston creates significant risks for the entire population.”
“Residents should pay close attention to social distancing and follow the statewide face-covering mandate that began earlier this month,” added Javier Nieto, dean of OSU’s College of Public Health and Human Services and another of TRACE’s leaders. “Other measures, such as avoiding large gatherings, will also help slow the spread of the virus, in line with the state of Oregon’s decision announced today to move Umatilla and Morrow counties back to phase one COVID-19 status. It is particularly important that individuals who have symptoms or who have tested positive follow state and county health guidelines such as self-isolating and seeking medical care.”
Hermiston is the largest city in northeastern Oregon at just over 18,000 people.