How Infections Change Tick Behavior and Survival

Some infections may improve tick survival.
Borrelia and Babesia can alter tick feeding behavior.
Researchers are studying how pathogens manipulate tick behavior.

In the article, “Pathogens Manipulating Tick Behavior—Through a Glass, Darkly,” Benelli reviews the literature on tick behavior triggered by infections with Anaplasma, Borrelia, Babesia, Bartonella, Rickettsia, and tick-borne encephalitis virus (TBEV).¹

You might think a deer tick would be worse off if infected. But not so. It appears that deer ticks are actually more likely to survive if they are infected with Borrelia, Anaplasma, or Babesia.

How Do These Pathogens Change Tick Behavior?

Benelli describes several behavioral changes that occur in infected ticks that may enhance survival and feeding activity.

• Nymphal deer ticks infected with Borrelia were able to climb higher, faster, and longer than ticks that were not infected. This increase in tick mobility boosts the tick’s questing and walking activity.
• Deer ticks infected with Borrelia are more likely to engorge more quickly by up-regulating the tick histamine release factor.
• Infections with Babesia and Bartonella also increase the tick’s ability to engorge.
• Borrelia and Anaplasma infection increase the tick’s resistance to desiccation (drying out). Borrelia does this by increasing the tick’s fat reserves. Anaplasma does this through the synthesis of heat shock proteins.
• Anaplasma infection improves the tick’s ability to survive in cold temperatures by enabling it to produce an antifreeze glycoprotein.

The author concludes that “being infected by Anaplasma, Borrelia and Babesia leads to increased tick survival.”

Benelli stresses the need for more research into the impact of other pathogen infections on tick behavior.

FAQ: Tick Behavior and Infection

Can infections change tick behavior?

Research suggests that infections with Borrelia, Babesia, and Anaplasma may alter tick mobility, feeding behavior, cold resistance, and survival.

Do infected ticks survive longer?

Some studies suggest infected ticks may survive environmental stress better than uninfected ticks, including resistance to cold temperatures and drying out.

Can infected ticks feed more effectively?

Benelli describes evidence that Borrelia, Babesia, and Bartonella infections may improve the tick’s ability to engorge during feeding.

How do ticks get on humans?

Ticks typically attach to humans while questing on tall grass, brush, leaves, or low vegetation. They do not jump or fly but cling to passing animals or people.

Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

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