Three of the cases were in Long Beach, which maintains its own health department and statistics, and two were in other parts of the county.
One of the cases is an individual who had a known history of travel to Japan, according to county public health director Barbara Ferrer. Health officials have not been able to determine a source of exposure for the second case, potentially making it the first community spread case.
The agency said it was identifying people may have had close personal contact with the patient in order to monitor them for possible symptoms, adding that there are no known public exposure locations related to these cases.
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The number of positive cases in the county stands at 19. The first case that was reported in the county has since been "resolved," while 15 infected individuals remain in isolation.
The three Long Beach cases announced Monday, two men and one women, are the first in that city. They were described as "presumptive" positive tests, meaning the results still have to be confirmed by the Centers for Disease Control and Prevention.
Of those three patients, one is hospitalized in stable condition and two are isolated at home. Two of them had traveled internationally recently where coronavirus is prevalent and one had traveled domestically.
"These preliminary test results, and our response and coordination with public health and safety officials are being taken extremely seriously," Long Beach Mayor Robert Garcia said. "We strongly believe that COVID-19 is a threat to public health here in Long Beach and throughout the United States."
The Long Beach Health Department is investigating to find out who may have been in contact with the individuals.
Long Beach residents can visit the city website for more local information about coronavirus.
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