The Gulf Coast tick, Amblyomma maculatum (Ixodida: Ixodidae) and spotted fever group Rickettsia in the highly urbanized northeastern US

Abstract

We report the multi-year collection of the Gulf Coast tick, Amblyomma maculatum Koch (Acaridae: Ixodida: Ixodidae) in Staten Island, New York City (NYC) as well as their detection in Brooklyn, NYC, and in Atlantic and Cumberland counties in southern NJ, USA. The first detections on all sites were of adults but in Freshkills Park on Staten Island larvae were collected in a following year. Based on known observations on birds of this tick species, it is likely A. maculatum are expanding north on migratory birds, which are now often seen in Freshkills Park. The presence of larvae indicates that adults are being successful at finding hosts in Staten Island. We describe the landscape features of the area in Staten Island where populations were highest and larvae were detected, which could have facilitated the establishment of A. maculatum. Notably, we also report the presence of human pathogens Rickettsia parkeri in 5/10 (50%) of adults tested and R. felis in 1/24 (4.17%) of larvae tested. In addition to established populations in Staten Island we found evidence of A. maculatum in NJ and other NYC boroughs, suggesting current or future establishment is possible. The failure thus far to detect established populations in these areas may be due to inherent difficulties in detecting low density, spatially heterogeneous incipient populations, which could require targeted surveillance efforts for this species. We discuss the consequences to public health of the establishment of A. maculatum and detection of two additional rickettsial pathogens in the densely populated Northeastern US.