New York Detects Borrelia mayonii in 1,600 Ticks, Confirming 1st Local Human Case
Updated
Updated · The Independent · Jun 10
New York Detects Borrelia mayonii in 1,600 Ticks, Confirming 1st Local Human Case
3 articles · Updated · The Independent · Jun 10
Summary
A Herkimer County resident who had not traveled out of state was diagnosed in June 2025 with Borrelia mayonii, marking New York’s first locally acquired human infection with the Lyme-causing bacterium.
Follow-up sampling found the same pathogen in black-legged ticks on the patient’s property, and a broader survey of nearly 1,600 ticks across 24 counties detected it only at that single site.
Researchers said the finding is the first documented evidence of B. mayonii in New York ticks and suggests local spread, likely through a vertebrate reservoir such as mice or squirrels.
B. mayonii has previously been identified only in Minnesota and Wisconsin and can cause more severe Lyme disease than the more common B. burgdorferi, sometimes requiring hospitalization.