Summary about Disease
Ehrlichiosis is a tickborne bacterial disease caused by bacteria of the Ehrlichia genus. It primarily affects white blood cells and can cause flu-like symptoms. The severity of the illness can range from mild to life-threatening, especially in individuals with weakened immune systems.
Symptoms
Common symptoms include:
Fever
Headache
Muscle aches
Fatigue
Nausea
Vomiting
Diarrhea
Cough
Confusion
Rash (more common in children than adults)
Red eyes
Causes
Ehrlichiosis is caused by bacteria belonging to the Ehrlichia genus. These bacteria are transmitted to humans through the bite of infected ticks, most commonly the lone star tick (*Amblyomma americanum*). The bacteria then infect and multiply within white blood cells.
Medicine Used
The primary treatment for ehrlichiosis is the antibiotic doxycycline. It is most effective when started early in the course of the illness. Other tetracycline antibiotics may be used if doxycycline is not appropriate.
Is Communicable
Ehrlichiosis is not directly communicable from person to person. It is only transmitted through the bite of an infected tick.
Precautions
Avoid tick-infested areas: Stay on marked trails when hiking and avoid bushy, wooded areas with high grass and leaf litter.
Use insect repellent: Apply insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone according to label instructions.
Wear protective clothing: Wear long sleeves, long pants, and socks when outdoors. Tuck pants into socks or boots.
Perform tick checks: Thoroughly check yourself, your children, and your pets for ticks after spending time outdoors.
Remove ticks promptly: Use fine-tipped tweezers to grasp the tick as close to the skin's surface as possible. Pull upward with steady, even pressure. Do not twist or jerk the tick. Clean the area with soap and water.
Shower soon after being outdoors: Showering within two hours of coming indoors has been shown to reduce your risk of getting Lyme disease and may be protective against other tickborne diseases.
How long does an outbreak last?
Ehrlichiosis does not typically occur in outbreaks in the same way as some viral infections. Individual cases occur when a person is bitten by an infected tick. The duration of illness for an individual case, if untreated, can last for several weeks and can become severe. With appropriate antibiotic treatment, symptoms usually resolve within a few days to a week.
How is it diagnosed?
Ehrlichiosis is diagnosed based on:
Symptoms: Clinical presentation consistent with ehrlichiosis.
History of tick exposure: Recent tick bite or exposure to tick-infested areas.
Blood tests:
Complete blood count (CBC): May show low white blood cell count, low platelet count, and elevated liver enzymes.
Polymerase chain reaction (PCR) test: Detects the Ehrlichia DNA in the blood.
Antibody testing: Detects antibodies against Ehrlichia bacteria (paired acute and convalescent serum samples are preferred).
Timeline of Symptoms
The incubation period (time from tick bite to symptom onset) is typically 5-14 days.
Early phase (first week): Fever, headache, muscle aches, fatigue, malaise.
Later phase (if untreated): More severe symptoms such as nausea, vomiting, diarrhea, cough, confusion, rash, respiratory distress, and potential organ damage.
Important Considerations
Early diagnosis and treatment are crucial to prevent serious complications.
Ehrlichiosis can be severe or even fatal, especially in older adults, immunocompromised individuals, and those with underlying health conditions.
Co-infections with other tickborne diseases (e.g., Lyme disease, anaplasmosis) are possible.
Even after treatment, some individuals may experience lingering fatigue or other symptoms.
There is no vaccine available for ehrlichiosis. Prevention relies on avoiding tick bites.