Two cases of measles have been confirmed in a Sacramento County family that recently traveled internationally, Sacramento County public health officials confirmed Tuesday. County officials said there was minimal exposure to the public and all potentially exposed people have been notified.These are the first confirmed measles cases of Sacramento County residents for 2018-2019, county officials told KCRA.So far there have been at least 30 cases of measles in California this year, according to the state's department of public health and local health officials.In Shasta County, health officials said Tuesday that an infant has been diagnosed with measles. More about the measlesThe disease is on the rise across the country, according to doctors.“Already this year in the U.S., there are more reported cases than the entire year of 2018,” said Dr. Dean Blumberg, chief of pediatric infectious diseases at the University of California, Davis Medical Center. “And we’re yet to come across the summer travel season.”We asked Blumberg what you need to know about the viral infection.Q: What are the symptoms?Blumberg: The tricky thing with measles is that when it starts, it starts out as fever, cough, runny nose, itchy runny eyes. You can see that with a lot of common, community-acquired viral infections. It’s not really specific for measles. As it evolves, you get a rash. The rash is pretty distinctive. It starts off on the head and the face and then moves down the body.Q: How is measles spread?Blumberg: Measles is so infectious. It’s transmitted through the airborne route and so it can hang out in the air in the room for up to two hours after the patient leaves. You don’t need person-to-person contact.Q: How long until symptoms appear?Blumberg: Most measles cases will occur between eight and 12 days within exposure, but they can occur up to three weeks later.Q: How effective is the measles vaccine?Blumberg: The measles vaccine is one of the most effective vaccines that we have. One dose will provide 97 percent of protection against measles, and two doses gets you up to 99 percent.Q: Can you get a vaccine, even after exposure?Blumberg: It’s never too late to vaccinate. People can get vaccinated later in life. They can even get vaccinated after exposure. It’ll provide some protection, so if people are behind or delayed with their immunizations, we do recommend getting them up to date.