LOS ANGELES — Santa Clara County health officials announced Sunday that a woman who recently traveled to Wuhan, China, has been infected with the new strain of coronavirus, marking the second confirmed case of the virus in the county and the fourth in California.

Two days earlier, a male resident of the county who had traveled to Wuhan was also infected with the virus, health officials said. More cases of the virus are expected because of the county’s high number of travelers to China, and because of close contact between those people and family members, officials said. Two other confirmed cases have been reported in Los Angeles and Orange counties.

Nine cases have now been confirmed in the United States.