Female black-legged tick, Ixodes scapularis. Content Provider CDC/Michael L. Levin, PhD; Photo Credit Jim Gathany https://wwwn.cdc.gov/phil/Details.aspx?pid=1669
The Wadsworth Center has identified Borrelia mayonii in blacklegged ticks (Ixodes scapularis) collected in New York State – the first time this Lyme disease-like pathogen has been detected outside the upper Midwest. B. mayonii causes an illness similar to Lyme disease and was first identified in a Minnesota patient approximately ten years ago. Ten ticks – one nymph and nine adults – from Herkimer County were positive for B. mayonii. Whole-genome sequencing is underway to further characterize the strains.
The finding resulted from a collaborative investigation involving the Wadsworth Center’s Bacterial Diseases Laboratory and the Center for Community Health’s Bureau of Communicable Disease Control and Vector Ecology Laboratory. More than 1,500 ticks from across the state were collected by scientists from the Vector Ecology Laboratory and tested using a newly developed real-time PCR assay designed and validated at the Wadsworth Center by an Association of Public Health Laboratories fellow and Center scientists.
This discovery strengthens surveillance for emerging tick-borne diseases and underscores the New York State Department of Health and Wadsworth Center’s leadership in protecting New Yorkers.
The findings were published in the Morbidity and Mortality Weekly Report (MMWR) on June 4, 2026.
Notes from the Field: Borrelia mayonii Lyme Disease - New York, 2025
Nafiz TN, Prusinski MA, Gubbala S, White J, Naik D, Sommer J, Wroblewski D. MMWR Morb Mortal Wkly Rep. 2026 Jun 4;75(21):271-272. doi: 10.15585/mmwr.mm7521a2. PMID: 42241371; PMCID: PMC13235943.
https://pubmed.ncbi.nlm.nih.gov/42241371/