 This is All Things Considered from NPR News. I'm Elsa Chang in Culver City, California. And I'm Ari Shapiro in Washington. It's been a record-breaking year for dengue cases in Central and South America, almost 10 million cases so far, more than any year on record. The Centers for Disease Control and Prevention is now warning of an increased risk of dengue infections in the U.S. NPR health correspondent Ping Huang is here to tell us about it. Hey, Ping. It's