Beware of ticks. A new CDC report reveals that certain ticks are able to pass a type of meat allergy, called alpha-gal syndrome, onto humans through their spit. Scientists believe that lone star ticks produce a sugar, known as alpha-gal, in their saliva. When these types of parasites makes contact with a person, the alpha-gal passes through the skin and causes their body to mark the sugar as a foreign invader. As a result, someone bit by a lone star tick can experience moderate to severe allergi