All About Ticks

All About Ticks

Ticks are arthropods that must bite and feed on blood of their host organism to survive and reproduce. They are arachnids, which means they are related to scorpions, spiders, and mites. While most ticks do not bite or feed on humans, certain species will bite humans incidentally, and can be vectors of illness to animals and humans alike. Worldwide, there are about 850 tick species and 30 major tick-borne diseases. In the U.S., there are nearly 90 of ticks, that, collectively can transmit pathogens that cause 11 major illnesses of human concern:

Lyme Disease
Tickborne Relapsing Fevers (soft tick and hard tick transmitted)
Rocky Mountain Spotted Fever
Rickettsia parkeri Rickettsiosis
Heartland and Bourbon Virus Diseases
Colorado Tick Fever
Powassan Virus Disease

tick species and pathogens

Different ticks in the US have the potential to transmit different pathogens. Not all ticks can transmit every potential pathogen.

Common tick species to be aware of in the US include:

  1. Black-legged tick (Ixodes scapularis) – found predominantly in the eastern US and midwest
  2. Lone Star tick (Amblyomma americanum) – found predominantly in the southeastern US, less commonly northeastern US.
  3. Brown dog tick (Rhipicephalus sanguineus) – found nearly everywhere
  4. American dog tick (Dermacentor variabilis) – found widely east of the Rockies and in California
  5. Rocky mountain wood tick (Dermacentor andersoni) – found predominantly in the Rockies (northwest US and SW Canada)
  6. Western black-legged tick (Ixodes pacificus) – found predominantly on the California coast