A red meat allergy caused by tick bites is an "emerging public health concern," according to two new studies from the Centers for Disease Control and Prevention. Alpha-gal syndrome (AGS) is a serious, potentially life-threatening allergic reaction that arises after people eat red meat or consume products with alpha-gal, a type of sugar found in most mammals, the CDC says. The syndrome is typically caused by a bite from the lone star tick, which transfers alpha-gal into the victim's body which in