We detected four pathogens in this black-legged deer tick from Berkshire County, Massachusetts: Borrelia burgdorferi (Lyme disease), Borrelia miyamotoi (hard tick relapsing fever), Babesia microti (babesiosis), and Anaplasma phagocytophilum (anaplasmosis)!

This western black-legged tick (Ixodes pacificus) from Marin County, California, was carrying both Borrelia burgdorferi and Anaplasma phagocytophilum!

This black-legged deer tick from Oconto County, Wisconsin, was carrying three pathogens: Borrelia burgdorferi (Lyme disease), Babesia microti (babesiosis), and Ehrlichia muris-like agent (ehrlichiosis)!

This nymphal lone star tick (Amblyomma americanum) from Anne Arundel County, Maryland, was carrying Borrelia lonestari, a bacterium that can cause southern tick-associated rash illness in its host.

We detected Ehrlichia ewingii in this lone star tick (Amblyomma americanum) from Camden County, New Jersey! This pathogen can cause ehrlichiosis if transmitted to its host.

No pathogens detected in this adult, male American dog tick from Ocean County, New Jersey! However, we have previously detected Anaplasma phagocytophilum in Dermacentor ticks from the state.

Two pathogens detected in this black-legged deer tick from Dukes County, Massachusetts: Borrelia burgdorferi (Lyme disease) and Babesia microti (babesiosis)!

We detected Borrelia miyamotoi in this black-legged deer tick from Carroll County, New Hampshire! B. miyamotoi is a bacterium that can cause hard tick relapsing fever if transmitted to the tick's host.

Borrelia burgdorferi was detected in this black-legged deer tick from our neighbors in Franklin County, Massachusetts! B. burgdorferi is the most common causative agent of Lyme disease.

#FlashbackFriday (May 2025): the Tick of the Week is a female American dog tick from DuPage County, Illinois, that was carrying Francisella tularensis. F. tularensis is a rare bacterium that can cause tularemia, a potentially serious illness, in its host.

This black-legged deer tick from Worcester County, Massachusetts, was carrying Borrelia burgdorferi, the most common causative agent of Lyme disease.

Our Tick of the Week comes to us from Norfolk County, Massachusetts! It was carrying Borrelia miyamotoi, a bacterium that can cause hard tick relapsing fever.

This female black-legged deer tick from Chittenden County, Vermont, was carrying THREE pathogens: Borrelia burgdorferi (Lyme disease), Babesia microti (babesiosis), and Anaplasma phagocytophilum (anaplasmosis).

This black-legged deer tick from Sheboygan County, Wisconsin, was carrying two pathogens. Borrelia burgdorferi is a bacterium that can cause Lyme disease and Babesia microti is a red blood cell parasite that can cause babesiosis.

This female black-legged deer tick from Middlesex County, Massachusetts, was carrying three pathogens: Borrelia burgdorferi (Lyme disease), Babesia microti (babesiosis), and Powassan virus!

Our Tick of the Week is a female black-legged deer tick from Washington County, Rhode Island, carrying THREE pathogens: Borrelia burgdorferi (Lyme disease), Borrelia miyamotoi (hard tick relapsing fever), and Anaplasma phagocytophilum (anaplasmosis)!

The Tick of the Week is a female black-legged deer tick from Steuben County, New York. We detected three pathogens in this specimen: Borrelia burgdorferi (Lyme disease), Borrelia miyamotoi (hard tick relapsing fever), and Anaplasma phagocytophilum (anaplasmosis). Spooky! 👻

Our Tick of the Week is a female black-legged deer tick from Hillsborough County, New Hampshire. We detected two pathogens: Borrelia burgdorferi (Lyme disease) and Anaplasma phagocytophilum (anaplasmosis)!

Our Tick of the Week is a female black-legged deer tick from Nova Scotia! We detected Borrelia burgdorferi, a bacterium that can cause Lyme disease.

We detected Anaplasma phagocytophilum, a bacterium that can cause anaplasmosis, in this male black-legged deer tick from Bergen County, New Jersey!