Please ensure Javascript is enabled for purposes of website accessibility
UCSF Study: COVID-19 Arrived in California From Multiple Locations
TLBBHMAP3-U010ALB5ANM-348f959abae2-512-300x300-1
By Jim Jakobs, Digital Producer
Published 5 years ago on
June 10, 2020

Share

University of California San Francisco researchers believe at least seven different COVID-19 lineages made their way into California.

Genome detectives using a method called “Genomic epidemiology,” tracked the virus evolution and spreadĀ in Northern California from late January to mid-March 2020.

Samples from 36 patients spanning nine counties and the Grand Princess cruise ship were tested.

Researchers just published a paper with their findings.

Swab Samples Screened

Scientists screened 62 respiratory swab samples from 54 COVID-19 patients available from hospitals and clinics at UCSF, the California Department of Public Health (CDPH), and eight county public health departments in Northern California.

The patient samples included:

  • 11 samples from the Grand Princess cruise ship, during its two voyages from San Francisco to Mexico and Hawaii in February and March 2020
  • 3 samples from a Solano County cluster that included the first reported case of community transmission in the U.S. with subsequent spread to two healthcare workers
  • 7 samples from Santa Clara County from a cluster associated with workspace transmission
  • 3 samples from patients who contracted the infection from a sick contacts
  • 5 samples related to domestic or international travel
  • 7 samples from additional cases of community transmission

COVID-19: Dispersed Across the Evolutionary Tree

Here is how the genomes from the samples broke down:

  • 14 in the Washington State lineage
  • 10 in a lineage associated with the Santa Clara County outbreak cluster
  • 3 from a Solano County cluster of 3 individuals
  • 5 related to lineages circulating in Europe and New York
  • 4 related to early lineages from Wuhan or other regions of China (including 2 patients from San Benito County with identical genomes)

Grand Princess Cruise Ship

A large outbreak was associated with the Grand Princess (with at least 78 confirmed positive cases out of 469 tested) as of March 26.

The chronologyĀ of the cruise ship outbreak suggested that the virus likely came from Washington state, although the cases may also have originated from a different region in which the original strain is circulating.

Santa Clara County Outbreak

UCSF researchers also studied seven genomes from individuals who were part of a local outbreak of COVID-19 at a large workplace facility with multiple employers, large areas of shared space, and heavy pedestrian traffic.

Four employeesĀ had dates of symptom onset within two weeks of each other, although they did not know each other.

It’s noted in the report that genomes from a Solano county resident and a San Mateo couple were also placed in the Santa Clara County outbreak cluster, suggesting possible spread to different counties. But, further investigation found the Solano County resident had visited a merchant in Santa Clara, during which he likely became infected.

Washington Outbreak

The study’s authors write there is growing evidence the Washington outbreak has lineage spread across the United States.

Washington lineage viruses have been identified in COVID-19 cases from many states including Minnesota, Connecticut, Utah, Virginia, and New York.

A copy of the entire article is below.


DON'T MISS

President Trumpā€™s Tariffs Could Be the Political Tipping Point

DON'T MISS

Order That Kept Water in the Kern River Reversed by 5th District Court of Appeal

DON'T MISS

As Dem Candidates for Governor Increase, They Wait for Harris to Decide

DON'T MISS

No More Calling ā€˜Shotgun?ā€™ CA Could Ban Teens From Riding in Front Seat

DON'T MISS

Protests Planned All Over the World Aimed at Donald Trump and Elon Musk

DON'T MISS

Average US Rate on a 30-Year Mortgage Dips to 6.64% for the Second Drop in 2 Weeks

DON'T MISS

Valley Crime Stoppers’ Most Wanted Person of the Day: Christopher Robert Sharkey

DON'T MISS

Fresno Man Arrested in Armed Robbery After Search Warrant Executed

DON'T MISS

Diehard Baseball Fans in Sacramento Welcome Athletics and Hope They Stay Awhile

DON'T MISS

Carbon Monoxide Was Cause of Death of Brett Gardner’s Teen Son, Officials Confirm

UP NEXT

Diehard Baseball Fans in Sacramento Welcome Athletics and Hope They Stay Awhile

UP NEXT

Flores Homers, Matos and Wade Also Go Deep to Help Giants Cap Sweep of Astros

UP NEXT

Californiaā€™s Schools Chief Has a $200,000 Salary and a Side Gig

UP NEXT

Trump Proposes Tax Deduction for Auto Loan Interest on US-Made Cars

UP NEXT

Western US Sees Sharp Increase in Extreme Weather Impact

UP NEXT

7-Year-Old Girl Was Killed by a Falling Boulder at a Lake Tahoe Ski Resort

UP NEXT

Xavier Becerra Enters 2026 California Governorā€™s Race

UP NEXT

Inside a $17 Billion Maintenance Backlog Plaguing Californiaā€™s Universities

UP NEXT

California Lawmakers Reject Bills to Restrict Transgender Youth in School Sports

UP NEXT

Elon Musk Reclaims Top Spot on Forbes’ Billionaires List

No More Calling ā€˜Shotgun?ā€™ CA Could Ban Teens From Riding in Front Seat

21 minutes ago

Protests Planned All Over the World Aimed at Donald Trump and Elon Musk

32 minutes ago

Average US Rate on a 30-Year Mortgage Dips to 6.64% for the Second Drop in 2 Weeks

42 minutes ago

Valley Crime Stoppers’ Most Wanted Person of the Day: Christopher Robert Sharkey

57 minutes ago

Fresno Man Arrested in Armed Robbery After Search Warrant Executed

1 hour ago

Diehard Baseball Fans in Sacramento Welcome Athletics and Hope They Stay Awhile

2 hours ago

Carbon Monoxide Was Cause of Death of Brett Gardner’s Teen Son, Officials Confirm

2 hours ago

Bettors Back Duke Men and UConn Women for National Championships

2 hours ago

Flores Homers, Matos and Wade Also Go Deep to Help Giants Cap Sweep of Astros

2 hours ago

Fresno County Authorities Need Help Finding Family of Alejandro Solis

2 hours ago

President Trumpā€™s Tariffs Could Be the Political Tipping Point

President Donald Trump called it “Liberation Day” on Wednesday as he unveiled reciprocal tariffs, but experts warn the move coul...

2 minutes ago

President Donald Trump holds a signed executive order during an event to announce new tariffs in the Rose Garden of the White House, Wednesday, April 2, 2025, in Washington. (AP/Evan Vucci)
2 minutes ago

President Trumpā€™s Tariffs Could Be the Political Tipping Point

9 minutes ago

Order That Kept Water in the Kern River Reversed by 5th District Court of Appeal

17 minutes ago

As Dem Candidates for Governor Increase, They Wait for Harris to Decide

21 minutes ago

No More Calling ā€˜Shotgun?ā€™ CA Could Ban Teens From Riding in Front Seat

On April 5th, the "Hands Off!" group will hold an international protest, including a Fresno demonstration at Fashion Fair Mall, urging Donald Trump and Elon Musk to stop their influence over vital social programs and rights. (Hands Off!)
32 minutes ago

Protests Planned All Over the World Aimed at Donald Trump and Elon Musk

A for sale sign stands outside a home on the market in the Alamo Placita neighborhood Tuesday, Aug. 27, 2024, in central Denver. (AP File)
42 minutes ago

Average US Rate on a 30-Year Mortgage Dips to 6.64% for the Second Drop in 2 Weeks

Christopher Robert Sharkey is Valley Crime Stoppers' Most Wanted Person of the Day for April 3, 2025. (Valley Crimes Stoppers)
57 minutes ago

Valley Crime Stoppers’ Most Wanted Person of the Day: Christopher Robert Sharkey

Johnny Hernandez, 38, was arrested in connection with an armed robbery at Adina Valley Market on April 1 and faces multiple felony charges, including robbery and assault with a firearm. (Fresno County SO)
1 hour ago

Fresno Man Arrested in Armed Robbery After Search Warrant Executed

Help continue the work that gets you the news that matters most.

Search

Send this to a friend