Rare Lyme Disease Variant Identified in Upstate New York

WHO:

Gizmodo - Researchers and local health officials in New York reported a case of Lyme disease caused by the bacterium Borrelia mayonii.

WSTM - An adult resident from Herkimer County was infected with B. mayonii Lyme disease.

WHAT:

Gizmodo - The case of Lyme disease caused by B. mayonii is the first ever detected in New York.

Gizmodo - The person made a full recovery after being treated with antibiotics.

WSTM - The New York State Health Department found a handful of ticks on the person’s property that tested positive for B. mayonii.

WSTM - A search of more than 1,500 ticks from 24 New York counties did not find B. mayonii again.

WHERE:

Gizmodo - The case was detected in Herkimer County, Central New York.

WSTM - The ticks were found on the person’s wooded property in Herkimer County.

WHEN:

Gizmodo - The person first experienced symptoms consistent with a tickborne infection in late June.

Gizmodo - The positive test result for B. mayonii was reported to the New York State Department of Health in early July.

Gizmodo - Ticks were collected and tested in July and again in October.

WHY:

Gizmodo - The discovery of B. mayonii in New York is troubling as it suggests the pathogen's spread, previously only found in the U.S. Midwest.

WSTM - A spokesperson from the New York State Health Department noted that a range of ticks and tick-borne diseases can change geographically over time.

HOW:

Gizmodo - Health officials began collecting and testing ticks found in the resident’s yard and surrounding areas after the positive test result.

Gizmodo - The researchers checked for B. mayonii in tick samples collected in other New York counties dating back to 2021 and found none.

(UPDATED June 6, 2026 01:37 UTC)

Researchers and local health officials in New York have reported the first-ever case of Lyme disease caused by the bacterium Borrelia mayonii, affecting an adult resident from Herkimer County, who has since made a full recovery after antibiotic treatment. The New York State Health Department discovered several ticks on the individual’s property that tested positive for B. mayonii, although a broader search of over 1,500 ticks from 24 counties did not reveal any additional cases. This discovery raises concerns about the potential spread of B. mayonii, which was previously only found in the U.S. Midwest, highlighting how tick-borne diseases can shift geographically over time.