New York has logged its first case of a rare form of Lyme disease previously seen only in the Upper Midwest. A CDC report says a Herkimer County adult who hadn’t traveled tested positive last July for Borrelia mayonii, the lesser-known of America’s two Lyme disease-causing species; the predominant one is Borrelia burgdorferi. A few infected ticks were found on the person’s property, but more than 1,500 ticks collected from 24 counties in the state turned up no additional signs of the bacteria.
B. mayonii infections, which have previously been limited to Minnesota and Wisconsin, can bring more nausea, vomiting, neurological issues, and a scattered rash instead of the classic bull’s-eye. Experts believe the bacteria has likely been in New York for a couple of years but remains confined to a small area, and they expect it to stay rare (it currently accounts for just two of Minnesota’s roughly 3,000 Lyme disease cases each year). As for how it might have arrived there, tick expert Douglas Norris tells NBC News it may have traveled via bird.