A New Zealand teenager hit Southern California on a vacation earlier this month, and she hit lots of the usual hot spots—including Disneyland, Universal Studios, and Madame Tussauds. The reason the world now knows about her trip is that it turns out she was infected with one of the most contagious diseases on the planet all the while—measles, reports the Los Angeles Times. Health authorities are now warning people they might have been exposed during her wanderings from Aug. 11 to Aug. 15. As a post at Science Alert notes, measles is so contagious that 90% of unvaccinated people exposed to it will come down with the disease over the next 7 to 21 days.
What's more, those infected can spread it before the telltale symptoms of fever, rash, cough, and irritated eyes turn up. "Measles is spread by air and by direct contact even before you know (you) have it," says a Los Angeles County health officer. The warning comes as the US is having one of its worst years for measles in decades, with about 1,200 people diagnosed so far, up from 372 in all of 2018. The infected girl flew into LAX on Aug. 11 and out again on Aug. 15. Authorities are trying to retrace her steps as much as possible to warn restaurant servers and others she might have had contact with to make sure they're immunized or to consider a booster shot. (New York made a controversial move to help contain an outbreak there.)