Post-Infectious Syndromes After Tick-Borne Illness
Post-infectious syndromes can occur after tick-borne illnesses, including Lyme disease and tick-borne encephalitis. Patients may experience persistent fatigue, pain, dizziness, sleep disruption, and cognitive difficulties even after the acute infection has been treated or resolved.
Post-infectious illness is recognized after many infections. In the case of tick-borne diseases, similar patterns have been reported following Lyme disease and tick-borne encephalitis (TBE).
Researchers increasingly recognize that some infections may be followed by prolonged immune, neurological, or autonomic disturbances, even after the acute illness has improved. Understanding these post-infectious processes may help explain why some individuals develop persistent symptoms after tick-borne illness.
Persistent Symptoms After Lyme Disease
A portion of patients treated for Lyme disease report ongoing symptoms that persist beyond the initial infection. These symptoms may include:
- fatigue
- joint and muscle pain
- headaches
- sleep disturbances
- difficulty concentrating
- memory problems
These persistent health problems are sometimes described as post-treatment Lyme disease syndrome (PTLDS).
Researchers have proposed several possible explanations for these symptoms, including:
- persistent immune activation following infection
- inflammatory responses triggered during the illness
- nervous system dysfunction affecting multiple body systems
These proposed mechanisms remain under investigation. However, the symptoms illustrate that recovery from infection can sometimes be complex and prolonged.
Post-Encephalitic Syndrome After Tick-Borne Encephalitis
Post-infectious syndromes are not unique to Lyme disease.
Patients recovering from tick-borne encephalitis, a viral infection transmitted primarily by Ixodes ticks, may develop a condition known as post-encephalitic syndrome (PES).
Bogovič and colleagues studied inflammatory immune responses in patients with tick-borne encephalitis by measuring 24 cytokines and chemokines involved in innate and adaptive immune responses.¹
The investigators reported that at least 30% of patients developed post-encephalitic syndrome, while approximately 5% developed permanent neurological deficits such as paresis.
Patients with PES commonly reported symptoms including:
- fatigue
- dizziness
- headaches
- sleep disorders
- emotional lability
- memory and concentration problems
The authors suggested that abnormal or prolonged immune responses after infection may contribute to these persistent symptoms. They also noted that immune system activity may take months or years to return to homeostasis after tick-borne encephalitis.¹
Immune-Mediated Illness After Infection
One proposed explanation for post-infectious syndromes is persistent immune activation.
During infection, the immune system releases signaling molecules such as cytokines and chemokines to help control pathogens. These immune responses are essential for fighting infection.
In some individuals, however, immune activation may persist longer than expected. Researchers are investigating whether this prolonged response can affect the brain, nerves, and other organs.
Studies of tick-borne encephalitis suggest that inflammatory immune responses may be associated with persistent neurological symptoms after infection.¹
Autonomic Dysfunction After Tick-Borne Infection
Some patients with persistent symptoms after infection develop problems involving the autonomic nervous system.
The autonomic nervous system regulates many automatic body functions, including:
- heart rate
- blood pressure
- digestion
- temperature regulation
When this system becomes disrupted, patients may experience symptoms such as:
- dizziness when standing
- heart palpitations
- fatigue
- exercise intolerance
This pattern is sometimes described as autonomic dysfunction or dysautonomia.
Autonomic disturbances have been reported after several infections. Their frequency and underlying mechanisms following individual tick-borne infections remain under investigation.
Clinical Perspective
Persistent symptoms following infection are not unique to Lyme disease. Similar post-infectious syndromes have been reported after viral infections, bacterial infections, and other tick-borne illnesses.
Studies of tick-borne encephalitis highlight an important point: infections transmitted by ticks may be followed by immune and neurological disturbances that persist long after the acute illness.
Recognizing these patterns may help clinicians better understand patients who continue to experience symptoms after tick-borne infections.
Persistent symptoms after tick-borne illness may involve the nervous system in multiple ways. In addition to direct involvement of the brain or nerves, some patients develop autonomic symptoms affecting heart rate, blood pressure, digestion, temperature regulation, and other automatic body functions.
In my clinical practice, I have seen patients with autonomic symptoms improve after treatment directed at a persistent tick-borne infection or coinfection. Babesia is particularly important to consider because doxycycline and amoxicillin, which are commonly prescribed for Lyme disease, are not effective treatments for babesiosis.
This clinical observation does not mean that every persistent symptom reflects an ongoing infection. It does highlight the importance of reassessing patients for untreated or inadequately treated coinfections before concluding that their illness is exclusively post-infectious.
These neurological complications are discussed further in the sections on neurologic Lyme disease and autonomic dysfunction in Lyme disease.
These issues reflect a broader challenge in medicine—understanding how infections interact with the immune and nervous systems over time. I discuss these challenges further in Why Lyme Disease Tests the Limits of Medicine.
References
- Bogovič P, Lusa L, Korva M, et al. Inflammatory immune responses in patients with tick-borne encephalitis: dynamics and association with the outcome of the disease. Microorganisms. 2019;7(11):514.
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
I believe this is me sounds exactly like my symptoms feeling hopeless
This article focuses on a tick-borne problem that is common in Europe. The study reminds people not to overlook Lyme disease in these patients. The study also reminds us of the need to understand the mechanism of chronic illness.
I was found having a negative lyme test. Unfortunately a little black tick bit me neck 1 1/2 years ago. I was extremely articulate, am losing so much of my vocabulary now. My balance has improved, however, when walking outside I still feel extremely unstable intermittently. I have had 8 kenalog injections in the last 1 1/2 years ( two to left foot, 1 to right foot, 2 to right knee, 3 to right shoulder) all for pain. Continue to have fatigue although it is better now. Have sleep problems. Up alot after sleepng 2 or 3 hrs, then, 2-3 hrs up until I can go back to sleep. Have not found a medical doctor who has any idea of what is wrong with me, completely egnoring the fact that a tick bit me in the neck. I have seen rhumatologist, neurologist, infectious disease, orthopedic and primary care.
I run into rheumatologists, neurologists, infectious disease specialists, orthopedics and primary care doctors who are talented but don’t address Lyme and tick-borne illnesses. I recommend a second opinion with a doctor experienced in diagnosing Lyme disease. You should also be aware that steroids can make a tick-borne illness more difficult to treat. Call my office at 914-666-4665 if you have any questions.
I miss you Sarah! Keep fighting