Rare Borrelia mayonii Lyme disease confirmed in New York

A rare form of Lyme disease has been confirmed for the first time in New York, marking a significant expansion of the pathogen's known range. State health officials and researchers detailed a case of Lyme disease caused by the bacterium Borrelia mayonii in a resident of Herkimer County, who was successfully treated with antibiotics last summer.

The discovery, documented in a report by the Centers for Disease Control and Prevention, provides the first evidence of B. mayonii presence in New York ticks and a locally acquired human infection in the state. Until now, this bacterium had only been identified in the Upper Midwest, primarily in Minnesota and Wisconsin. The infected individual had not traveled recently, indicating the bacteria is now present in the local tick population.

Following the diagnosis in early July, health officials collected and tested ticks from the patient's property and surrounding areas. They found one nymph and nine adult blacklegged ticks, also known as deer ticks, that tested positive for B. mayonii. A broader screening of over 1,500 ticks collected from across 24 New York counties since 2021 found no other instances of the bacterium, suggesting its...