SLO County has the most coronavirus cases from Ventura to San Jose. This might be why
Editor’s note: The data in this story is current as of 1:30p.m. on Friday, March 27. Counties are constantly updating their coronavirus numbers, so check Public Health Department websites for the latest information.
San Luis Obispo County has the most confirmed coronavirus cases of any county between Ventura and San Jose — even those with significantly larger populations — but it’s not entirely clear why.
The county on Saturday announced 67 local residents have tested positive for COVID-19, the illness caused by coronavirus.
In comparison, Santa Barbara County had 47 confirmed cases, Monterey County had 32 cases, Fresno County had 31 and Kern County had 40, as of Friday.
All of those counties have far larger populations than San Luis Obispo. Between Los Angeles and the Bay Area, only Ventura County had more coronavirus cases with 83 patients, as of Friday.
When you consider the population differences, San Luis Obispo County’s rate is even more stark.
As of Friday, San Luis Obispo County had about 24 confirmed patients per 100,000 people. Santa Barbara County, which has the second-highest number of cases per capita, was home to only 11 COVID-19 patients per 100,000 people.
Monterey County had less than six, Kern County had four, and Fresno had three.
SLO County testing capability
Dr. Penny Borenstein, San Luis Obispo County Public Health officer, said at a Wednesday news conference that the county’s testing capability may be contributing to the larger number of patients.
The county had conducted 348 local tests with 27 positive results, as of Friday. Private labs — which are required to report only their positive tests — had received 32 positive results.
San Luis Obispo County is home to one of 22 labs in California testing samples for COVID-19. Monterey, Tulare and Ventura counties have the closest neighboring Public Health labs.
Fresno County doesn’t have its own Public Health lab, and officials who collect testing specimens send them to Tulare County or Quest Diagnostics, which has a contract with the county, said Sim Dhillon, a county health education specialist.
It can take 24 hours to two days to get results, Dhillon said.
San Luis Obispo County’s lab is helping to test patients in Santa Barbara County, Borenstein said.
“They are using our Public Health laboratory,” she said. “We are a regional lab, and so for hospitalized patients, we are actually running those specimens on their behalf. But for all of their other patients, they are having to send those out to other laboratories that are not having the same turnaround time as we have. They may be a little delayed in their numbers because of that turnaround time.”
Comparing testing county-by-county
It’s tough to gauge the number of tests different California Public Health agencies and private labs have performed.
Private labs have been increasing their COVID-19 testing capacity, with some reporting more positive results than Public Health labs. But some counties don’t receive data on the total number of tests, and some report testing numbers that combine information from private and public labs.
For example, San Luis Obispo County reported the Public Health Department has conducted 348 tests, but there’s no data on how many tests private labs have performed for local residents.
Santa Barbara County reported 608 tests have been performed for local patients, but doesn’t indicate whether those tests were conducted privately or on behalf of the Public Health Department.
Monterey County’s Public Health Department had conducted 403 tests, but the agency doesn’t report data on the number of private tests performed.
Kern County reported 1,777 tests performed for local residents, but it’s unclear how many of those tests were conducted for the Public Health Department and how many were conducted privately.
Fresno County’s Public Health Department had 165 tests performed on its behalf and reported 160 private tests have been performed for local residents for a total of 325 total tests.
Borenstein also said it’s tough to compare counties due to potential differences in the criteria patients must meet in order to get tested.
She said San Luis Obispo County officials are offering COVID-19 tests to contacts of household cases and are also conducting testing in vulnerable communities.
“County by county, I’m not exactly sure what their criteria are,” she said. “Our higher numbers may, in some respect, reflect more aggressive testing and not so much more disease, but that’s just my best understanding of the situation.”
This story was originally published March 27, 2020 at 5:00 AM.
