This tick can give you a life-threatening allergy. It’s spreading across the U.S.

Peak tick season is here — and the fastest-growing tick-borne illness in the country is alpha-gal syndrome, a condition that causes an often-severe allergy to red meat and other animal products. It’s primarily spread by lone-star ticks, once confined to the Southeast but now found as far north as Maine and Michigan. The syndrome can trigger a range of reactions — from hives to anaphylaxis — and at least one death has been attributed to it. New Yorker staff writer Burkhard Bilger, who has reported on the syndrome’s rise, joins *Apple News In Conversation* guest host David Greene to explain how it was discovered, why it can take years to diagnose, and how it’s reshaping the way people eat, work, and spend time outdoors.