The Department of Health and Human Services says California has more than 10 million cases of the Zika virus, and about a million of them are among travelers traveling to and from Florida.
The state also reported more than 20 deaths and 2,400 hospitalizations.
The number of people who are infected in the United States has risen more than fivefold since the pandemic began in 2015.
Officials say the surge in cases is likely caused by the arrival of the virus in the state and its close proximity to Florida.
This is the first confirmed case of Zika in the U.S. since March.
Health officials are urging people in the Sunshine State to be cautious of mosquitoes, especially those traveling to areas with large populations of the mosquito-borne virus.
Florida’s Department of Public Health and the state’s health department have warned of a higher risk of mosquito-related illnesses among the Zika-infected population in Florida, including the possible transmission of the disease in the medical community.
In California, health officials say they’ve seen a higher number of cases of Zika than in previous outbreaks, including cases in the Golden State and Florida.
The Department of Homeland Security says there are no confirmed cases of Ebola in the country.