The county had previously confirmed two cases in the area, including one which involved a non-resident who traveled to Wuhan.
There have now been seven confirmed cases in the county this year.
Los Angeles previously had one case of coronavirus, but that patient was discharged from the hospital after making a full recovery.
Earlier on Wednesday, health officials announced the first California death from the virus, an elderly person with underlying health conditions. The patient was an elderly adult with underlying health conditions who tested positive for the coronavirus after returning from a cruise, the statement read.
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In an update, World Health Organization has raised its risk assessment of the deadly disease from "high" to "very high". But the Center for Disease Control and Prevention confirmed the first cases of the novel virus in the U.S. days later.
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Manchester City top scorer Sergio Aguero is fit despite being forced off in the Carabao Cup final with a cut. Rodri's cross was headed into Aguero's path by Phil Foden and the Argentine struck into the net.
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Samsung's Galaxy A50 and Galaxy A10 rounded out the next spots as the third and fourth best selling phones of 2019, respectively. Note that Huawei is now selling nearly all its smartphones in China after the Huawei Ban imposed by the U.S. government.
The director of the County of Los Angeles Public Health Department, Dr. Barbara Ferrer, told CNBC that all six cases are connected to "an assumed known exposure", and that the department is improving on its testing capacity. Six new cases were also reported in the city Tuesday.
The City of Santa Monica says there are no known cases in Santa Monica and that they are working closely with the L.A. County Department of Public Health to monitor coronavirus.
L.A. mayor Eric Garcetti signed a declaration of a state of local emergency Wednesday morning for the city.
"This declaration of a local emergency will facilitate out efforts to coordinate with all our partners and jointly implement effective strategies to protect our residents", said Supervisor Kathryn Barger.
"The last thing we want to do is create more fear in our community", she said at the press conference. The virus has killed nine people in the United States since the outbreak, all of them in Washington. "Fear will not drive our responses".