Three people in the Coachella Valley have tested positive for the novel coronavirus, in addition to the case announced over the weekend, Riverside health officials said Monday, March 9.

Two of the individuals have been isolated at home, while the third is being cared for at a Coachella Valley hospital, Dr. Cameron Kaiser, Riverside County public health officer, said in a news release.

Health investigators think the three new infections resulted either from travel into areas where COVID-19 has been confirmed or from contact with a known case, Kaiser said in the release.

The announcement comes after Kaiser reported late Saturday that a Riverside County resident acquired coronavirus and is under treatment at Eisenhower Health in Rancho Mirage.

Public health officials said they have not been able to determine how that individual was infected. That means the case is considered “community spread.”

Community spread — the transmission of an illness where there isn’t a known source such as recent travel or contact with a known case — suggests that COVID-19 is present in the community, Kaiser said.

That’s something health officials had wanted to avoid because it makes tracking the disease harder, county health spokesman Jose Arballo Jr. said.

“When it’s unknown origin, it’s literally anywhere in the community,” Arballo said.

Kaiser said he is recommending those in the Coachella Valley who are elderly and have underlying health conditions — including individuals who are HIV positive — limit non-essential travel and avoid large public gatherings.

The news release also said an additional passenger on the Diamond Princess Cruise ship who is from Riverside County has tested positive for the disease. Like the other Riverside County resident who got the disease while on that ship, the newest former passenger is receiving treatment at a Northern California hospital and has not been to Riverside County since leaving the ship, Kaiser said.

That makes a total of six Riverside County residents who have tested positive for COVID-19. None of the individuals have been identified because of confidentiality laws.

Kaiser declared a public health emergency Sunday, after the first locally acquired case was detected. The declaration is subject to ratification by the Riverside County Board of Supervisors at their Tuesday meeting.

While no novel coronavirus cases have been confirmed in San Bernardino County, the board of supervisors will consider declaring a health emergency at its Tuesday, March 10, meeting Chairman Curt Hagman said.

Los Angeles County, which has had 16 known cases as of Monday, reported what could be that county’s first instance of community spread on Monday, March 9.

As of Monday morning, California had 133 confirmed COVID-19 cases, not counting passengers from the Grand Princess cruise ship currently off the coast of California.

That included 19 cases of community transmission.

More than 10,300 people are self-monitoring after returning to the United States through San Francisco International or Los Angeles International airports, the California Department of Public Health said in a news release Monday.

There have been calls for the cancellation of the Coachella Valley Music and Arts Festival and sister event the Stagecoach Country Music Festival, set to run on three consecutive weekends: April 10-12, 17-19 and 24-26. Promoter Goldenvoice has not released a statement regarding the future of the festivals.

“Ultimately it’s the public health officers driving the conversation,” said Brooke Beare, director of communications and marketing for the city of Indio, where the festivals are held.

Indio calls itself the City of Festivals, with Coachella and Stagecoach among the best attended. Coachella attracts 250,000 attendees, according to the city’s 2020 economic forecast; Stagecoach draws 85,000. The local economic impact is $403 million, and the global impact is $705 million, according to a 2016 report by Development Management Group, an economic analysis firm in Palm Desert, which was commissioned by AEG/Goldenvoice.

Kaiser has been speaking with festival organizers to gather information regarding a potential cancellation or postponement, Arballo said. Similar facts were considered before the BNP Paribas Open tennis tournament, set to begin this week at Indian Wells in the Coachella Valley, was postponed.

Public health officials advise that people avoid places where people meet or gather and avoid using public transportation, if possible. People should not attend work or school if they are sick, should cough into their elbow or a tissue, and should wash hands frequently and use hand sanitizer often. They should also stay away from anyone who is sick, the news release recommends.

Staff writer Fielding Buck contributed to this report.