Ehrlichiosis is the general name used to describe several bacterial diseases that affect animals and humans. Human ehrlichiosisis a disease caused by at least three different ehrlichial species.

At-Risk Populations

Ehrlichiosis is sometimes fatal, especially in the elderly, those with compromised immune systems, and those who have had their spleens removed.


The following symptoms are commonly seen with this disease, however, it is important to note that the combination of symptoms varies greatly from person to person; fever, headache, chills, malaise, muscle pain, nausea/vomiting/diarrhea, confusion, conjunctival injection (red eyes), and rash (in up to 60% of children, less than 30% of adults).

How It Spreads

It spreads through the bite of infected ticks.


Reducing exposure to ticks is the best defense against Lyme disease, Rocky Mountain spotted fever, Babesiosis, Ehrlichiosis, and other tickborne infections.

Removing Ticks

Testing & Diagnosis

In symptomatic people, ehrlichiosis usually is diagnosed by examining blood specimens under a microscope and seeing inclusions called morulae inside white blood cells. Serology and molecular methods are also important to establish the diagnosis.


Babesiosis can be treated with antibiotics.

Publications & Resources