Officials with the New York City Department of Health and Mental Hygiene issued a tickborne disease advisory last week for city clinicians to be on the alert for patients with tickborne diseases.


Recent travel to upstate NY, Long Island, and other parts of New England should prompt consideration of tickborne diseases. A history of a tick bite is not a prerequisite for considering tickborne diseases for patients with compatible illness, since only a small proportion of patients diagnosed with these diseases recall being bitten by a tick.

Tickborne diseases in NYC have been trending upward since 2000, with fluctuations from year to year.

In 2017, the number of anaplasmosis and babesiosis cases approximately doubled in all boroughs except Queens, compared to 2016. There was a slight increase in Lyme disease cases in Brooklyn, Manhattan, and Queens.

Incidence rates of tickborne diseases are typically significantly higher in residents of Manhattan compared with other boroughs. However, since 2015, Staten Island has had the highest incidence rate of Lyme disease in NYC, which may be due to an increasing number of locally acquired cases.

Local transmission of babesiosis was also reported in the Bronx and Staten Island and there was one report each of locally acquired anaplasmosis and ehrlichiosis in Staten Island residents. Blacklegged ticks collected in the Bronx and Staten Island have tested positive for Borrelia burgdorferi and Babesia microti. Locally acquired RMSF cases while rare, have been reported in the past from all five boroughs.

Tickborne diseases may also be transmitted via blood transfusion. In 2017, there was one transfusion-associated babesiosis case and the first anaplasmosis case acquired from a blood transfusion in NYC.

A look at tick surveillance in NYC shows Ixodes scapularis (blacklegged tick or deer tick) has become widely established in Staten Island, and focal areas of the Bronx including Pelham Bay Park and Hunter Island. It is not established in other areas of NYC.

In 2016, ticks collected from parks in the Bronx (47%) and Staten Island (19%) tested positive for Borrelia burgdorferi.

A much smaller number of ticks in the Bronx and Staten Island tested positive for Anaplasma phagocytophilum (0.06-10%), Babesia microti (0-6%) and the emerging pathogen, Borrelia miyamotoi (2%).