Santa Clara County reported a second case of measles within one week on Friday, saying a county resident contracted the infection while traveling abroad.
Public risk from the case is very low, according to the county, which is contacting everyone who may have come into contact with the person.
The case is unrelated to one reported on Tuesday involving an international traveler who visited 20 locations in the county last week.
County public health officials said the rate of measles vaccination in Santa Clara County is very high, so most people are protected from the infection. People with weakened immune systems or unvaccinated children are at higher risk.
County Health Officer Dr. Sara Cody said to call a doctor immediately if anyone who may have contracted measles experiences fever, cough, red eyes, runny nose and a rash beginning on the face.
Health officials also reminded anyone planning international travel to make sure they are up to date on their vaccinations.