Anaplasmosis and Lyme Disease: Coinfection Symptoms and Treatment
Anaplasmosis and Lyme disease coinfection can cause an acute febrile illness with high fever, severe headache, chills, and characteristic laboratory abnormalities.
The same black-legged tick that transmits Lyme disease can also carry Anaplasma phagocytophilum, the bacterium responsible for anaplasmosis.
When both infections occur together, patients may feel significantly sicker—and much earlier—than expected with Lyme disease alone.
For a broader overview, see our coinfections hub.
What Is Anaplasmosis?
Anaplasmosis is a bacterial infection transmitted by Ixodes scapularis ticks, the same ticks that spread Lyme disease, Babesia, and other tick-borne infections.
Unlike Lyme disease, which may evolve more gradually, anaplasmosis typically presents as an acute febrile illness within 1–2 weeks of a tick bite—sometimes before Lyme disease symptoms even appear.
The bacteria infect white blood cells, particularly neutrophils, leading to immune dysfunction and characteristic laboratory abnormalities.
Symptoms of Anaplasmosis and Lyme Disease Coinfection
Patients with anaplasmosis often develop symptoms suddenly and may become severely ill within days.
Common symptoms include:
- High fever, often 102–104°F
- Severe headache
- Chills and sweats
- Profound fatigue
- Muscle aches and body pain
- Nausea, vomiting, or diarrhea
Unlike Lyme disease, anaplasmosis rarely causes an erythema migrans rash.
Patients with coinfection may also experience overlapping Lyme disease symptoms, including joint pain, neurologic symptoms, or persistent fatigue.
Characteristic Laboratory Findings
Laboratory abnormalities can provide important diagnostic clues in anaplasmosis.
Typical findings include:
- Low white blood cell count (leukopenia)
- Low platelet count (thrombocytopenia)
- Elevated liver enzymes
When these abnormalities occur alongside high fever and tick exposure, clinicians should strongly consider anaplasmosis—even before confirmatory testing returns.
Why Anaplasmosis Is Often Missed
Anaplasmosis is frequently mistaken for influenza or another viral illness because the symptoms develop rapidly and resemble a severe flu-like infection.
The diagnosis may also be missed when clinicians do not ask about recent tick exposure, hiking, gardening, or outdoor activity.
Testing can further complicate the diagnosis. Early serology may be negative, while PCR testing is not always available.
Because treatment delays can lead to severe complications, clinicians often begin doxycycline based on clinical suspicion alone.
Can Lyme Disease and Anaplasmosis Occur Together?
Yes. A single tick bite can transmit both Lyme disease and anaplasmosis simultaneously.
Patients with coinfection may experience the acute febrile illness of anaplasmosis together with the musculoskeletal, neurologic, or fatigue-related symptoms associated with Lyme disease.
This overlap can make the clinical picture more confusing—and more severe.
Coinfections may also overlap with other tick-borne illnesses. Learn more about Babesia and Bartonella and Lyme disease.
Treatment of Anaplasmosis
Doxycycline is the first-line treatment for both Lyme disease and anaplasmosis.
Many patients experience significant improvement within 24–48 hours after starting treatment, especially when fever is present.
Treatment should not be delayed while waiting for confirmatory test results when clinical suspicion is high.
Delayed therapy increases the risk of serious complications, including respiratory failure, kidney injury, bleeding problems, and neurologic symptoms.
When to Suspect Anaplasmosis
Clinicians should consider anaplasmosis in any patient with:
- Acute high fever after tick exposure
- Severe headache and chills
- Low white blood cells or platelets
- Elevated liver enzymes
- Coinfection symptoms suggesting Lyme disease
In endemic regions, these findings warrant prompt treatment with doxycycline while diagnostic testing is underway.
FAQ
What are the main symptoms of anaplasmosis?
High fever, severe headache, chills, muscle aches, fatigue, and abnormal laboratory findings such as low white blood cells and platelets.
How is anaplasmosis different from Lyme disease?
Anaplasmosis usually causes a sudden febrile illness within days to weeks of tick exposure, while Lyme disease often develops more gradually and may include rash, joint pain, or neurologic symptoms.
Can you have Lyme disease and anaplasmosis together?
Yes. Both infections are transmitted by the same tick species, making coinfection possible after a single bite.
How is anaplasmosis treated?
Doxycycline is the preferred treatment and is effective against both anaplasmosis and Lyme disease.
Clinical Takeaway
Anaplasmosis and Lyme disease coinfection can produce a severe acute illness with high fever, headache, and characteristic laboratory abnormalities.
When fever, low blood counts, and tick exposure occur together, clinicians should consider anaplasmosis early and begin prompt doxycycline treatment.
Related Articles
- Lyme Disease Coinfections
- Babesia: The Most Common Lyme Coinfection
- Bartonella and Lyme Disease
- Ehrlichiosis and Lyme Disease
- Lyme Disease Symptoms Guide
References
- Bakken JS, Dumler JS. Human granulocytic anaplasmosis. Infect Dis Clin North Am. 2015;29(2):341-355.
- Dumler JS, Barbet AF, Bekker CPJ, et al. Reorganization of genera in the families Rickettsiaceae and Anaplasmataceae in the order Rickettsiales. Int J Syst Evol Microbiol. 2001;51(6):2145-2165.
- Sanchez E, Vannier E, Wormser GP, Hu LT. Diagnosis, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: A Review. JAMA. 2016;315(16):1767-1777.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
