New York Detects 1st Borrelia mayonii Lyme Case as State Lyme Incidence Jumps 450%
Updated
Updated · NBC News · Jun 4
New York Detects 1st Borrelia mayonii Lyme Case as State Lyme Incidence Jumps 450%
3 articles · Updated · NBC News · Jun 4
Summary
A CDC report said an adult in Herkimer County contracted Borrelia mayonii in July 2025, marking the first known New York case of the rare Lyme-causing bacterium previously seen only in Minnesota and Wisconsin.
A handful of ticks from the person's wooded property tested positive, but a broader search of more than 1,500 ticks across 24 counties found no additional traces, suggesting the bacterium is confined to a very small area.
Borrelia mayonii can cause fever and headache like standard Lyme disease, but is more likely to bring nausea, vomiting, broader rashes and neurological symptoms rather than the classic bullseye rash.
New York's overall Lyme incidence rose nearly 450% between 2020 and 2024, though experts expect B. mayonii to remain rare; in Minnesota it causes about 2 of roughly 3,000 annual Lyme cases.
Researchers do not know how the bacterium reached New York, though a bird-borne tick is one possibility, and they say climate change is expanding the Northeast's tick-friendly range even if it likely did not drive this specific arrival.