Tick surveillance data sets

Ixodes scapularis and Ixodes pacificus by county in the contiguous United States

  • Counties classified as “established” are those where six or more ticks of a single life stage or more than one life stage of the tick were collected in the county within a 12-month period.
  • Counties classified as “reported” are those where less than six ticks of a single life stage were collected in the county within a 12-month period.
  • Counties classified as “no records” should not be interpreted as the tick being absent. No records could be a result of a lack of sampling efforts, tick collections, or a lack of reporting or publishing the results of sampling efforts.

Established and reported records of I. pacificus and I. scapularis through Dec. 31, 2021 excel icon[XLS – 685 KB]––Right–click the link and select “save”.

Tickborne pathogens identified in host-seeking Ixodes spp. ticks: Status by county in the United States

  • 2021 Update: Pathogens included in dataset:
    • Borrelia burgdorferi sensu stricto
    • Borrelia mayonii
    • Borrelia miyamotoi
    • Anaplasma phagocytophilum
    • Ehrlichia muris eauclairensis
    • Babesia microti
    • Powassan virus
  • Counties classified as “present” are those where indicated tickborne pathogens have been identified in one or more host-seeking Ixodes scapularis or Ixodes pacificus ticks, using pathogen species-specific molecular methods.
  • Counties classified as “no records” should not be interpreted as the pathogen being absent. No records could be a result of a lack of sampling efforts, tick collections, pathogen testing in collected ticks, or a lack of reporting or publishing the results of sampling efforts.

Established and reported records of Borrelia burgdorferi sensu stricto or Borrelia mayonii through Dec. 31, 2021 excel icon[XLS – 354 KB]––Right–click the link and select “save”.