COVID-19 cluster traced to Southern California birthday party: Health department

The Pasadena Public Health Department is reminding residents to stay home after a cluster of COVID-19 cases were traced to a birthday party in the Southern California city.

More than five confirmed cases and "many more ill individuals" were tied to the party, the department announced. The party was held in early April, after the state's stay-at-home order went into effect.

The first patient identified with the disease in connection to the outbreak was coughing and not wearing a face mask at the party, the department said. Guests, which included a "large number" of extended family members and friends, also were not wearing face coverings or practicing social distancing, according to the department.

"This is an example of how good contact tracing can identify disease clusters and tell us more about the spread of disease in our community," Dr. Matthew Feaster, an epidemiologist with the Pasadena Public Health Department, said in a statement on Saturday.

California's stay-at-home order went into effect on March 19. On Friday, the order was modified to allow curbside retail.

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Dr. Ying-Ying Goh, director of the Pasadena Public Health Department, reminded residents in a statement that "gatherings of people who do not live in the same household are still prohibited."

"The virus remains highly contagious," Goh said. "Social distancing, frequent hand washing and wearing face coverings remain our best defenses against the further spread of COVID-19 in our community."

California has 66,680 confirmed cases of COVID-19 and 2,745 deaths, according to the latest figures from the state.

ABC News' Matt Fuhrman contributed to this report.

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