Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatmentPrognosisPrevention
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Prognosis
Prevention
While many cases are mild with flu-like symptoms, the infection can be severe; it can even cause death. Treatment with antibiotics is needed to prevent complications.
The History of EhrlichiosisThe first human case of ehrlichiosis was identified in 1986. From 2000 to 2011, there were hundreds of reported cases ofEhrlichia chaffeensis(the most commonly reported type of ehrlichiosis) each year. By 2012, there were more than 1,000 annual cases, and in 2019 there were 2,093 cases reported.Although it’s considered a nationally reportable disease, many experts believe that ehrlichiosis is underreported and that the actual number of infected people is significantly higher.
The History of Ehrlichiosis
The first human case of ehrlichiosis was identified in 1986. From 2000 to 2011, there were hundreds of reported cases ofEhrlichia chaffeensis(the most commonly reported type of ehrlichiosis) each year. By 2012, there were more than 1,000 annual cases, and in 2019 there were 2,093 cases reported.Although it’s considered a nationally reportable disease, many experts believe that ehrlichiosis is underreported and that the actual number of infected people is significantly higher.
The first human case of ehrlichiosis was identified in 1986. From 2000 to 2011, there were hundreds of reported cases ofEhrlichia chaffeensis(the most commonly reported type of ehrlichiosis) each year. By 2012, there were more than 1,000 annual cases, and in 2019 there were 2,093 cases reported.
Although it’s considered a nationally reportable disease, many experts believe that ehrlichiosis is underreported and that the actual number of infected people is significantly higher.
epantha / iStock / Getty Images
What Are the Symptoms of Ehrlichiosis?
The symptoms which commonly occur early on in the disease process include:
The rash is seen in one in three affected people and more often appears in children than adults. It develops five days after the fever begins and can either be a splotchy red rash or pinpoint dots.
In some cases, such as when a person has a weakened immune system, serious complications can occur from ehrlichiosis, including:
It is possible to have symptoms of ehrlichiosis that are so mild, that a person may never realize they have the disease. In this instance, the body may fight off the disease without treatment. But ehrlichiosis that is left untreated could lead to serious symptoms that require hospitalization.
Serious complications are rare in younger, healthy people. When they do occur in healthy folks, it’s usually a result of delayed treatment. In a small percentage of people with serious complications, death has been known to be the outcome.
People are most likely to become infected with ehrlichiosis during the spring and summer months. This is because the number of infected ticks is usually higher during those seasons. But, it’s possible to become infected with the disease during the autumn months as well.
What Causes Ehrlichiosis?
E. chaffeensisproduces the majority of infections, withE. ewingiialso being common.
Rickettsial bacteria cause several serious diseases including:
A tick must be attached to the skin for at least 24 hours before it’s able to transmit disease-causing bacteria (such as ehrlichiosis). Therefore, it’s vital to detect and remove any embedded ticks as soon as possible as a prevention measure.
A tick usually acquires the bacteria that causes ehrlichiosis from an infected deer, dog, or rodent. Then they transmit the bacteria to humans when they bite the skin.
If you live in one of the areas of the country where one of these ticks reside, you may be at risk for getting ehrlichiosis.
The Centers for Disease Control and Prevention (CDC) reported that in 2019, Missouri, Arkansas, North Carolina, and New York accounted for nearly half of all reported cases of ehrlichiosis (E. chaffeensis) in the U.S.
On rare occasions, blood that has been infected has been known to cause ehrlichiosis through blood transfusions or organ transplants.
It’s also been suggested that the disease may be transmitted from a pregnant person to the fetus, as well as through direct contact with an infected animal that is being slaughtered (such as a deer).However, more research is needed.
Diagnosing Ehrlichiosis
Blood tests may be taken to confirm the presence of the type of bacteria causing ehrlichiosis. Other types of blood tests may be performed including the following:
Ehrlichiosis Treatment
The treatment of choice for ehrlichiosis is a course of antibiotics. Usually, an antibiotic called doxycycline is administered for both children and adults with ehrlichiosis. In severe cases, antibiotics may be given intravenously (IV) at a hospital until symptoms begin to subside.
Symptoms usually decline very fast (within the first few days) after antibiotics are given. Severe complications, such as organ failure, may require additional treatment like kidney dialysis or breathing support.
Is Ehrlichiosis Curable?
The prognosis (outlook) of ehrlichiosis is good when a person gets prompt treatment. Usually, the symptoms will clear up within a few days after treatment with antibiotics.
Unlike other tick-borne illnesses, such as Lyme disease, ehrlichiosis is not a chronic (long-term) disease, but rather an acute (short-term) condition that responds very well to antibiotic treatment.
However, in a very small percentage of people (around 1%) who do not receive treatment early enough in the disease process, death has been known to occur. Most often those who die from the disease are young children (under the age of 10) or adults who are aged 70 or older. This is because young children and older adults usually have a weaker immune system.
Other people at high risk of mortality (death) from ehrlichiosis are those with severe health conditions that impact the immune system (such as cancer or HIV).
How to Identify a Tick Bite (and Prevent Future Bites)
Summary
11 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Ehrlichiosis. epidemiology and statistics.Columbia University Irving Medical Center. Lyme and Tick-Borne Diseases Research Center.Ehrlichiosis.Centers for Disease Control and Prevention.Ehrlichiosis: Signs and symptoms.Cedars-Sinai Health Library.Ehrlichiosis.Infection Prevention and You.What is sepsis?Texas Health and Human Services.Ehrlichiosis.Centers for Disease Control and Prevention.CDC Yellow Book 2024: Rickettsial diseases.Centers for Disease Control and Prevention.CDC yellow book chapter 4: travel-related infectious diseases.Centers for Disease Control and Prevention.General Distribution of Blacklegged Ticks (Ixodes scapularis).Mowla SJ, Drexler NA, Cherry CC, Annambholta PD, Kracalik IT, Basavaraju SV.Ehrlichiosis and anaplasmosis among transfusion and transplant recipients in the united states.Emerg Infect Dis. 2021;27(11):2768-2775. doi:10.3201/eid2711.211127UpToDate.Human ehrlichiosis and anaplasmosis.
11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.Ehrlichiosis. epidemiology and statistics.Columbia University Irving Medical Center. Lyme and Tick-Borne Diseases Research Center.Ehrlichiosis.Centers for Disease Control and Prevention.Ehrlichiosis: Signs and symptoms.Cedars-Sinai Health Library.Ehrlichiosis.Infection Prevention and You.What is sepsis?Texas Health and Human Services.Ehrlichiosis.Centers for Disease Control and Prevention.CDC Yellow Book 2024: Rickettsial diseases.Centers for Disease Control and Prevention.CDC yellow book chapter 4: travel-related infectious diseases.Centers for Disease Control and Prevention.General Distribution of Blacklegged Ticks (Ixodes scapularis).Mowla SJ, Drexler NA, Cherry CC, Annambholta PD, Kracalik IT, Basavaraju SV.Ehrlichiosis and anaplasmosis among transfusion and transplant recipients in the united states.Emerg Infect Dis. 2021;27(11):2768-2775. doi:10.3201/eid2711.211127UpToDate.Human ehrlichiosis and anaplasmosis.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.Ehrlichiosis. epidemiology and statistics.Columbia University Irving Medical Center. Lyme and Tick-Borne Diseases Research Center.Ehrlichiosis.Centers for Disease Control and Prevention.Ehrlichiosis: Signs and symptoms.Cedars-Sinai Health Library.Ehrlichiosis.Infection Prevention and You.What is sepsis?Texas Health and Human Services.Ehrlichiosis.Centers for Disease Control and Prevention.CDC Yellow Book 2024: Rickettsial diseases.Centers for Disease Control and Prevention.CDC yellow book chapter 4: travel-related infectious diseases.Centers for Disease Control and Prevention.General Distribution of Blacklegged Ticks (Ixodes scapularis).Mowla SJ, Drexler NA, Cherry CC, Annambholta PD, Kracalik IT, Basavaraju SV.Ehrlichiosis and anaplasmosis among transfusion and transplant recipients in the united states.Emerg Infect Dis. 2021;27(11):2768-2775. doi:10.3201/eid2711.211127UpToDate.Human ehrlichiosis and anaplasmosis.
Centers for Disease Control and Prevention.Ehrlichiosis. epidemiology and statistics.
Columbia University Irving Medical Center. Lyme and Tick-Borne Diseases Research Center.Ehrlichiosis.
Centers for Disease Control and Prevention.Ehrlichiosis: Signs and symptoms.
Cedars-Sinai Health Library.Ehrlichiosis.
Infection Prevention and You.What is sepsis?
Texas Health and Human Services.Ehrlichiosis.
Centers for Disease Control and Prevention.CDC Yellow Book 2024: Rickettsial diseases.
Centers for Disease Control and Prevention.CDC yellow book chapter 4: travel-related infectious diseases.
Centers for Disease Control and Prevention.General Distribution of Blacklegged Ticks (Ixodes scapularis).
Mowla SJ, Drexler NA, Cherry CC, Annambholta PD, Kracalik IT, Basavaraju SV.Ehrlichiosis and anaplasmosis among transfusion and transplant recipients in the united states.Emerg Infect Dis. 2021;27(11):2768-2775. doi:10.3201/eid2711.211127
UpToDate.Human ehrlichiosis and anaplasmosis.
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
